Πέμπτη, 26 Απριλίου 2018

Papillary thyroid microcarcinoma: characteristics at presentation, and evaluation of clinical and histological features associated with a worse prognosis in a Latin American cohort.

Papillary thyroid microcarcinoma: characteristics at presentation, and evaluation of clinical and histological features associated with a worse prognosis in a Latin American cohort.

Arch Endocrinol Metab. 2018 Feb;62(1):6-13

Authors: Domínguez JM, Nilo F, Martínez MT, Massardo JM, Muñoz S, Contreras T, Carmona R, Jerez J, González H, Droppelmann N, León A

Abstract
Objective We aimed to describe the presentation of papillary microcarcinoma (PTMC) and identify the clinical and histological features associated with persistence/recurrence in a Latin American cohort. Subjects and methods Retrospective study of PTMC patients who underwent total thyroidectomy, with or without radioactive iodine (RAI), and who were followed for at least 2 years. Risk of recurrence was estimated with ATA 2009 and 2015 classifications, and risk of mortality with 7th and 8th AJCC/TNM systems. Clinical data obtained during follow-up were used to detect structural and biochemical persistence/recurrence. Results We included 209 patients, predominantly female (90%), 44.5 ± 12.6 years old, 183 (88%) received RAI (90.4 ± 44.2 mCi), followed-up for a median of 4.4 years (range 2.0-7.8). The 7th and 8th AJCC/TNM system classified 89% and 95.2% of the patients as stage I, respectively. ATA 2009 and ATA 2015 classified 70.8% and 78.5% of the patients as low risk, respectively. Fifteen (7%) patients had persistence/recurrence during follow-up. In multivariate analysis, only lymph node metastasis was associated with persistence/recurrence (coefficient beta 4.0, p = 0.016; 95% CI 1.3-12.9). There were no PTMC related deaths. Conclusions Our series found no mortality and low rate of persistence/recurrence associated with PTMC. Lymph node metastasis was the only feature associated with recurrence in multivariate analysis. The updated ATA 2015 and 8th AJCC/TNM systems classified more PTMCs than previous classifications as low risk of recurrence and mortality, respectively.

PMID: 29694628 [PubMed - in process]



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Fast in situ gamma spectroscopy using hand-held spectrometer with NaI probe.

https:--linkinghub.elsevier.com-ihub-ima Related Articles

Fast in situ gamma spectroscopy using hand-held spectrometer with NaI probe.

J Environ Radioact. 2018 Aug;188:87-94

Authors: Guguła S, Kozak K, Mazur J, Grządziel D, Mroczek M

Abstract
In this work a hand-held spectrometer InSpector 1000 with NaI (Tl) 2″ x 2″ detector has been adapted to fast in situ gamma-ray spectroscopy. Two specially designed mounting stands with shielding have been built, allowing conducting measurements in different geometries. Three particular geometries (NW, IS50, IS00) have been chosen for efficiency calibration and further study. The first one (NW) is intended for small environmental samples (volume ca 140 cm3) collected on site. IS50 geometry is a typical in situ geometry meant for radioactivity measurements in soil with detector pointed towards the ground. In this geometry the probe is shielded and mounted 50 cm above the soil surface. The new proposed geometry IS00 is designed in the way that the detector is inserted directly into the soil in order to increase the counting efficiency. The methods of efficiency calibration involved using calibration standards (in NW geometry) and the results obtained in previous in situ measurements with InSpector 2000 portable spectrometer with HPGe detector and ISOCS™ Shield Systems, which is routinely used in environmental measurements. NW geometry turned out to be useful for natural radioisotopes concentrations (K-40, U-238 and Th-232), which significantly exceed typical values of those concentrations observed in Poland. Both IS50 and IS00 geometries are applicative for quick (2 h long measurement) evaluation of typical concentrations of K, U and Th in soils. The newly proposed geometry IS00 is superior as it showed lower detection limits and uncertainties as well as its handling was far easier than of IS50. Authors have proven that hand-held spectrometer InSpector 1000, together with mounting stands and shielding, can be successfully used for fast in situ gamma-spectroscopy. Its relatively small weight and good mobility are additional assets. Moreover, detailed procedures for measurements in each geometry have been developed to conduct such analyses properly.

PMID: 29021085 [PubMed - indexed for MEDLINE]



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11C-methionine positron emission tomography for target delineation of recurrent glioblastoma in re-irradiation planning

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Publication date: May–June 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 3
Author(s): Hidekazu Tanaka, Takahiro Yamaguchi, Kae Hachiya, Kazuhiro Miwa, Jun Shinoda, Masahide Hayashi, Shinichi Ogawa, Hironori Nishibori, Satoshi Goshima, Masayuki Matsuo
AimTo define the optimal margin on MRI scans in the re-radiation planning of recurrent glioblastoma using methionine positron emission tomography (MET-PET).BackgroundIt would be very useful if the optimal margin on MRI to cover the uptake area on MET-PET is known.Materials and MethodsCT, MRI, and MET-PET were performed separately over the course of 2 weeks. Among the MRI scans, we used the contrast-enhanced T1-weighted images (Gd-MRI) and T2-weighted images (T2-MRI). The Gd-MRI-based clinical target volume (CTV) (CTV-Gd) and the T2-MRI-based CTV (CTV-T2) were defined as the contrast-enhanced area on Gd-MRI and the high intensity area on T2-MRI, respectively. We defined CTV x mm (x=5, 10, 15, 20) as x mm outside the CTV. MET-PET-based CTV (CTV-MPET) was defined as the area of accumulation of MET-PET. We calculated the sensitivity and specificity of CTV-Gd and CTV-T2 following comparison with CTV-MPET, which served as the gold standard in this study.ResultsThe sensitivity of CTV-T2 5mm (98%) was significantly higher than CTV-T2 (87%), and there was no significant difference in the sensitivity between CTV-T2 5mm and CTV T2 10, 15, or 20mm. The sensitivity of CTV-Gd 20mm (97%) was lower than that of CTV-T2 5mm (98%).ConclusionsA margin of at least 5mm around the high intensity area on T2-MRI is necessary in the target volume delineation of recurrent glioblastoma for the coverage of MET-PET findings in re-radiation therapy planning.



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Quantitative analysis of the perimeniscal position of the inferior lateral genicular artery (ILGA): magnetic resonance imaging study.

Quantitative analysis of the perimeniscal position of the inferior lateral genicular artery (ILGA): magnetic resonance imaging study.

Surg Radiol Anat. 2018 Apr 24;:

Authors: Park J, Lee SS, Kim TW

Abstract
PURPOSE: The inferior lateral genicular artery (ILGA) passes around the lateral knee joint, adjacent to the lateral meniscus (LM). ILGA injuries in total knee arthroplasty or arthroscopic surgery can result in recurrent hemarthrosis or painful pseudoaneurysms. Detailed information about the perimeniscal position of the ILGA relative to the LM is necessary to avoid these complications.
METHODS: 3-T MR images of 100 knees (mean age 36.3 ± 11.2 years) were retrospectively reviewed. The perimeniscal area was divided into four regions: the anterior, middle, popliteal hiatus, and posterior zones. In each zone, the ILGA diameter, superoinferior position (assessed as the height of the ILGA from the LM base), and distance between the meniscocapsular junction and the ILGA were measured.
RESULTS: The distance between the ILGA and meniscocapsular junction was significantly smaller in the middle zone than in the other three zones (anterior 5.3 ± 0.8 mm, middle 1.4 ± 0.4 mm, popliteal hiatus 6.1 ± 1.0 mm, and posterior 5.6 ± 1.5 mm, p < 0.05). In the superoinferior position, the height of the ILGA was 3.4 ± 0.9 mm in the anterior zone, 0.4 ± 1.3 mm in the middle zone, - 1.9 ± 1.8 mm in the popliteal hiatus zone, and - 1.3 ± 4.3 mm in the posterior zone. When the LM bottom is the base, the ILGA was located superiorly in the anterior zone, close to the base in the middle zone, and inferiorly in the popliteal hiatus zone.
CONCLUSIONS: To avoid ILGA injury, close attention is necessary during surgical procedures involving the meniscocapsular junction of the LM, especially at the meniscal base in the middle zone.

PMID: 29694643 [PubMed - as supplied by publisher]



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Changes in the ADC of diffusion-weighted MRI with the oscillating gradient spin-echo (OGSE) sequence due to differences in substrate viscosities

Abstract

Purpose

Compared with the conventional pulsed gradient spin-echo (PGSE) sequence, diffusion-weighted imaging (DWI) with the oscillating gradient spin-echo (OGSE) sequence can shorten the diffusion time by changing the frequency. The purpose was to investigate whether n-alkanes are suitable as isotropic phantoms for estimating the diffusion coefficient with the OGSE sequence.

Materials and methods

We investigated changes in the apparent diffusion coefficient (ADC) due to differences in the viscosities of nine n-alkane phantoms with different numbers of carbon atoms from C8H18 to C16H34 using OGSE and PGSE sequences at 21 °C. Effective diffusion times of 4.3, 5.1, 6.5, 9.3, 20, 40, and 60 ms were used. The T2 relaxation times of each n-alkane phantom were measured using quantitative synthetic magnetic resonance imaging (MRI). Circular regions of interest were placed manually within the alkane phantoms on ADC and T2 maps.

Results

In each alkane phantom, changes in mean ADC values were almost constant with changes in diffusion times. Viscosities and ADC values showed inverse proportionality, as expected theoretically.

Conclusion

The ADC values of alkanes do not depend on diffusion times. The n-alkanes can be useful phantoms for assessing the accuracy of clinical protocols of DWI with the OGSE sequence.



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Τετάρτη, 25 Απριλίου 2018

Post mortem CT angiography in fetuses or newborn: very affordable pump and catheter solution

Publication date: Available online 25 April 2018
Source:Journal of Forensic Radiology and Imaging
Author(s): Wolf Schweitzer, Michael Thali, Rosa Maria Martinez, Lars Ebert
This technical note describes a pump and catheter setup that is geared towards performing post mortem computed tomography angiography (PMCTA) examinations in fetal humans. With a voltage controlled very affordable immersion pump and a modified butterfly injection needle, relatively stable linear voltage flow rate relationships can be obtained across flow rates in the range of 30 to 150 ml/min. Flow rates are calculated and compared with actual measurements, whereas practical results suggest a degree of turbulence within the setup used. Practical testing with a fetal pig results in excellent vascular filling. This was subject to considerable partial volume effect, however, so using a micro computed tomography scanner for better quality scans of PMCTA for fetal humans is highly recommended.



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Editorial Board



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Contents



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Important ESTRO dates



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Corrigendum to “PO0994 Integrin antagonistic drugs reveal different effectiveness in 2D monolayer vs. 3D spheroid culture” [Radiother. Onco. 123(Suppl. 1) (2017), S544]

The authors regret that the order of authors in the above mentioned abstract, were published in an incorrect order. The correct listing is shown above.

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Quality of radiotherapy services in post-Soviet countries: An IAEA survey

The quality of radiotherapy services in post-Soviet countries has not yet been studied following a formal methodology. The IAEA conducted a survey using two sets of validated radiation oncology quality indicators (ROIs).

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Impact of Patient Age and Histological Type on Radioactive Iodine Avidity of Recurrent Lesions of Differentiated Thyroid Carcinoma.

Related Articles

Impact of Patient Age and Histological Type on Radioactive Iodine Avidity of Recurrent Lesions of Differentiated Thyroid Carcinoma.

Clin Nucl Med. 2018 Apr 23;:

Authors: Nakanishi K, Kikumori T, Miyajima N, Takano Y, Noda S, Takeuchi D, Iwano S, Kodera Y

Abstract
BACKGROUND: Age is a prognostic factor for recurrent differentiated thyroid carcinoma (DTC) and may be related to radioactive iodine (RAI) nonavidity. Indications for molecular-targeted drugs (MTDs) are currently limited to RAI-refractory DTC. Demonstrating refractoriness to RAI, mainly indicated by RAI nonavidity, may be a barrier to the introduction of MTDs for elderly patients. The present study was conducted to evaluate the impact of age and histological type on the RAI avidity of recurrent lesions of DTC.
METHODS: Two hundred fifty-eight patients (189 patients with classic papillary thyroid carcinoma [cPTC], 8 patients with follicular variant of papillary thyroid carcinoma, and 61 patients with follicular thyroid carcinoma), who underwent their first RAI whole-body scanning for recurrent DTC at our institution between 2004 and 2013, were retrospectively studied. Radioactive iodine uptake was determined by visible uptake by metastatic lesion(s) in a diagnostic RAI-whole-body scan.
RESULTS: The prevalence of RAI-avid lung metastases in cPTC indicated a significant, inverse correlation with age (<55 years, 36.2%; ≥55 years, 3%; P < 0.001). By contrast, for follicular thyroid carcinoma, the prevalence of RAI avidity was not influenced by age. Similar tendencies were observed for lymph node metastases.
CONCLUSIONS: Radioactive iodine avidity by metastatic lesions of cPTC in elderly patients, especially those older than 55 years, was seldom demonstrated. Adherence to a strategy of restricting MTD administration after confirmation of RAI refractoriness should be revisited for elderly patients. A strategy of omitting RAI treatment should be taken into account when considering age and histological type.

PMID: 29688947 [PubMed - as supplied by publisher]



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THE TRENDS OF HYPERTHYROIDISM TREATMENT IN TAIWAN: A NATIONWIDE POPULATION-BASED STUDY.

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THE TRENDS OF HYPERTHYROIDISM TREATMENT IN TAIWAN: A NATIONWIDE POPULATION-BASED STUDY.

Endocr Pract. 2018 Apr 24;:

Authors: Kornelius E, Yang YS, Huang CN, Wang YH, Lo SC, Lai YR, Chiou JY

Abstract
OBJECTIVE: Over the past three decades, few studies on hyperthyroidism treatment trends have been reported. Therefore, we used a nationwide population-based database to evaluate the current practices and management of hyperthyroidism in Taiwan.
METHODS: This retrospective study included a random selection of 1 million people in Taiwan between 2004 and 2010. Hyperthyroidism patients who received anti-thyroid drugs (ATD), radioactive iodine (RAI), or surgery were identified. We calculated the proportion and treatment trends of those 3 treatment options annually. Poisson regression model was used to determine whether there was a change of trends in hyperthyroidism patients. P < 0.05 was considered statistically significant.
RESULTS: The prevalence of overt hyperthyroidism increased steadily in Taiwan from 2,666 (0.27%) in 2004, to 3,464 (0.37%) in 2010. The incidence of hyperthyroidism (per 1,000 persons) also increased from 0.97 in 2004 to 1.06 in 2010. The major proportion of hyperthyroidism in this study was Graves' disease (95%), followed by toxic nodular goiter (2%), and other causes (3%). ATD is the most commonly used (96-97%) treatment for hyperthyroidism, followed by surgery (2-3%), and RAI (<1%). There was a significant decreasing trend for surgery, which decreased from 2.9% in 2004 to 2% in 2010, especially in female patients (3.3% in 2004 to 2.3% in 2010, p <001) and patients younger than 40 (3.8% in 2004 to 2.9% in 2010, p <001). Meanwhile, the proportion of ATD and RAI remain unchanged. The most common ATD prescription was methimazole (45-50%), followed by propylthiouracil (30-32%) and carbimazole (19-21%).
CONCLUSION: For the period 2004-2010, ATD was the treatment of choice in Taiwan, followed by surgery and RAI.

PMID: 29688762 [PubMed - as supplied by publisher]



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Abdominal manifestations of IgG4-related disease: a pictorial review

Abstract

In the last decade, autoimmune pancreatitis has become recognised as part of a wider spectrum of IgG4-related disease, typically associated with elevated serum IgG4 levels and demonstrating a response to corticosteroid therapy. Radiologically, there is imaging overlap with other benign and neoplastic conditions. This pictorial review discusses the intra-abdominal manifestations of this disease on cross-sectional imaging before and after steroid treatment and the main radiological features which help to distinguish it from other key differentials.

Teaching Points

Autoimmune pancreatitis is part of a spectrum of IgG4-related disease.

Diagnosis is based on raised serum IgG4, clinical, radiological and histopathological findings.

Cross-sectional imaging can demonstrate the typical findings of abdominal IgG4-related disease.

Cross-sectional imaging can be used to monitor response to corticosteroid treatment.



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Brain-injured Survivors of Monochorionic Twin Pregnancies Complicated by Single Intrauterine Death: MR Findings in a Multicenter Study.

Related Articles

Brain-injured Survivors of Monochorionic Twin Pregnancies Complicated by Single Intrauterine Death: MR Findings in a Multicenter Study.

Radiology. 2018 Apr 24;:

Authors: Conte G, Righini A, Griffiths PD, Rustico M, Lanna M, Mackie FL, Pinelli L, Prefumo F, Persico N, Igra MS, Parazzini C, Doneda C, Fichera A, Ambrosi C, Kilby M, Severino M, Triulzi F, Rossi A, Skipper N

Abstract
Purpose To describe and classify the range of brain injuries present at prenatal, in-utero magnetic resonance (MR) imaging in co-twin survivors of monochorionic (MC) twin pregnancies complicated by single intrauterine death (SIUD). Materials and Methods This retrospective, observational study from six tertiary fetal medicine centers that perform tertiary-level prenatal in-utero MR studies reviewed cases in which prenatal in-utero MR imaging had shown a brain injury in a surviving co-twin of a twin pregnancy with a MC component complicated by SIUD. Results Forty-two surviving MC twins were described. The primary distinction of brain abnormalities was into nonfocal and focal lesions. The nonfocal lesions included periventricular leukomalacia (group 1; two fetuses), generalized encephalomalacia (group 2; nine fetuses), posterior encephalomalacia (group 3; seven fetuses), and bilateral parasagittal and perisylvian injury (group 4; three fetuses). The focal lesions included nonhemorrhagic lesions (group 5; 14 fetuses) and hemorrhagic lesions (group 6; seven fetuses). Focal brain lesions were more likely to be found in the surviving MC pregnancies complicated by twin-twin transfusion syndrome (TTTS) (odds ratio, 2.4; 95% confidence interval: 1.3, 18.5; P = .01) and in fetuses that underwent an obstetric intervention (odds ratio, 2.8; 95% confidence interval: 1.8, 23.6; P = .006). Conclusion Brain injury of the surviving co-twin after SIUD in MC pregnancies is usually of ischemic origin and spares the brainstem and cerebellum. Focal brain lesions are more frequent in pregnancies complicated by TTTS or in those where an intervention has been performed.

PMID: 29688161 [PubMed - as supplied by publisher]



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Developmental Hip Dysplasia Diagnosis at Three-dimensional US: A Multicenter Study.

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Developmental Hip Dysplasia Diagnosis at Three-dimensional US: A Multicenter Study.

Radiology. 2018 Apr 24;:172592

Authors: Zonoobi D, Hareendranathan A, Mostofi E, Mabee M, Pasha S, Cobzas D, Rao P, Dulai SK, Kapur J, Jaremko JL

Abstract
Purpose To validate accuracy of diagnosis of developmental dysplasia of the hip (DDH) from geometric properties of acetabular shape extracted from three-dimensional (3D) ultrasonography (US). Materials and Methods In this retrospective multi-institutional study, 3D US was added to conventional two-dimensional (2D) US of 1728 infants (mean age, 67 days; age range, 3-238 days) evaluated for DDH from January 2013 to December 2016. Clinical diagnosis after more than 6 months follow-up was normal (n = 1347), borderline (Graf IIa, later normalizing spontaneously; n = 140) or dysplastic (Graf IIb or higher, n = 241). Custom software accessible through the institution's research portal automatically calculated indexes including 3D posterior and anterior alpha angle and osculating circle radius from hip surface models generated with less than 1 minute of user input. Logistic regression predicted clinical diagnosis (normal = 0, dysplastic = 1) from 3D indexes (ie, age and sex). Output represented probability of hip dysplasia from 0 to 1 (output: >0.9, dysplastic; 0.11-0.89, borderline; <0.1, normal). Software can be accessed through the research portal. Results Area under the receiver operating characteristic curve was equivalently high for 3D US indexes and 2D US alpha angle (0.996 vs 0.987). Three-dimensional US helped to correctly categorize 97.5% (235 of 241) dysplastic and 99.4% (1339 of 1347) normal hips. No dysplastic hips were categorized as normal. Correct diagnosis was provided at initial 3D US scan in 69.3% (97 of 140) of the studies diagnosed as borderline at initial 2D US scans. Conclusion Automatically calculated 3D indexes of acetabular shape performed equivalently to high-quality 2D US scans at tertiary medical centers to help diagnose DDH. Three-dimensional US reduced the number of borderline studies requiring follow-up imaging by over two-thirds.

PMID: 29688160 [PubMed - as supplied by publisher]



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Radiomics of CT Features May Be Nonreproducible and Redundant: Influence of CT Acquisition Parameters.

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Radiomics of CT Features May Be Nonreproducible and Redundant: Influence of CT Acquisition Parameters.

Radiology. 2018 Apr 24;:172361

Authors: Berenguer R, Pastor-Juan MDR, Canales-Vázquez J, Castro-García M, Villas MV, Legorburo FM, Sabater S

Abstract
Purpose To identify the reproducible and nonredundant radiomics features (RFs) for computed tomography (CT). Materials and Methods Two phantoms were used to test RF reproducibility by using test-retest analysis, by changing the CT acquisition parameters (hereafter, intra-CT analysis), and by comparing five different scanners with the same CT parameters (hereafter, inter-CT analysis). Reproducible RFs were selected by using the concordance correlation coefficient (as a measure of the agreement between variables) and the coefficient of variation (defined as the ratio of the standard deviation to the mean). Redundant features were grouped by using hierarchical cluster analysis. Results A total of 177 RFs including intensity, shape, and texture features were evaluated. The test-retest analysis showed that 91% (161 of 177) of the RFs were reproducible according to concordance correlation coefficient. Reproducibility of intra-CT RFs, based on coefficient of variation, ranged from 89.3% (151 of 177) to 43.1% (76 of 177) where the pitch factor and the reconstruction kernel were modified, respectively. Reproducibility of inter-CT RFs, based on coefficient of variation, also showed large material differences, from 85.3% (151 of 177; wood) to only 15.8% (28 of 177; polyurethane). Ten clusters were identified after the hierarchical cluster analysis and one RF per cluster was chosen as representative. Conclusion Many RFs were redundant and nonreproducible. If all the CT parameters are fixed except field of view, tube voltage, and milliamperage, then the information provided by the analyzed RFs can be summarized in only 10 RFs (each representing a cluster) because of redundancy.

PMID: 29688159 [PubMed - as supplied by publisher]



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Prospective Comparison of the Diagnostic Accuracy of MR Imaging versus CT for Acute Appendicitis.

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Prospective Comparison of the Diagnostic Accuracy of MR Imaging versus CT for Acute Appendicitis.

Radiology. 2018 Apr 24;:171838

Authors: Repplinger MD, Pickhardt PJ, Robbins JB, Kitchin DR, Ziemlewicz TJ, Hetzel SJ, Golden SK, Harringa JB, Reeder SB

Abstract
Purpose To compare the accuracy of magnetic resonance (MR) imaging with that of computed tomography (CT) for the diagnosis of acute appendicitis in emergency department (ED) patients. Materials and Methods This was an institutional review board-approved, prospective, observational study of ED patients at an academic medical center (February 2012 to August 2014). Eligible patients were nonpregnant and 12- year-old or older patients in whom a CT study had been ordered for evaluation for appendicitis. After informed consent was obtained, CT and MR imaging (with non-contrast material-enhanced, diffusion-weighted, and intravenous contrast-enhanced sequences) were performed in tandem, and the images were subsequently retrospectively interpreted in random order by three abdominal radiologists who were blinded to the patients' clinical outcomes. Likelihood of appendicitis was rated on a five-point scale for both CT and MR imaging. A composite reference standard of surgical and histopathologic results and clinical follow-up was used, arbitrated by an expert panel of three investigators. Test characteristics were calculated and reported as point estimates with 95% confidence intervals (CIs). Results Analysis included images of 198 patients (114 women [58%]; mean age, 31.6 years ± 14.2 [range, 12-81 years]; prevalence of appendicitis, 32.3%). The sensitivity and specificity were 96.9% (95% CI: 88.2%, 99.5%) and 81.3% (95% CI: 73.5%, 87.3%) for MR imaging and 98.4% (95% CI: 90.5%, 99.9%) and 89.6% (95% CI: 82.8%, 94.0%) for CT, respectively, when a cutoff point of 3 or higher was used. The positive and negative likelihood ratios were 5.2 (95% CI: 3.7, 7.7) and 0.04 (95% CI: 0, 0.11) for MR imaging and 9.4 (95% CI: 5.9, 16.4) and 0.02 (95% CI: 0.00, 0.06) for CT, respectively. Receiver operating characteristic curve analysis demonstrated that the optimal cutoff point to maximize accuracy was 4 or higher, at which point there was no difference between MR imaging and CT. Conclusion The diagnostic accuracy of MR imaging was similar to that of CT for the diagnosis of acute appendicitis.

PMID: 29688158 [PubMed - as supplied by publisher]



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Three-dimensional US in Infants with Developmental Dysplasia of the Hip: Ready for Prime Time.

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Three-dimensional US in Infants with Developmental Dysplasia of the Hip: Ready for Prime Time.

Radiology. 2018 Apr 24;:180141

Authors: Jaramillo D

PMID: 29688157 [PubMed - as supplied by publisher]



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Radiation Segmentectomy for Hepatocellular Carcinoma: Ready for Prime Time?

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Radiation Segmentectomy for Hepatocellular Carcinoma: Ready for Prime Time?

Radiology. 2018 Apr 24;:180163

Authors: Sofocleous CT, Boas FE

PMID: 29688156 [PubMed - as supplied by publisher]



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Radiation Segmentectomy: Potential Curative Therapy for Early Hepatocellular Carcinoma.

Related Articles

Radiation Segmentectomy: Potential Curative Therapy for Early Hepatocellular Carcinoma.

Radiology. 2018 Apr 24;:171768

Authors: Lewandowski RJ, Gabr A, Abouchaleh N, Ali R, Al Asadi A, Mora RA, Kulik L, Ganger D, Desai K, Thornburg B, Mouli S, Hickey R, Caicedo JC, Abecassis M, Riaz A, Salem R

Abstract
Purpose To report long-term outcomes of radiation segmentectomy (RS) for early hepatocellular carcinoma (HCC). The authors hypothesized that outcomes are comparable to curative treatments for patients with solitary HCC less than or equal to 5 cm and preserved liver function. Materials and Methods This retrospective study included 70 patients (median age, 71 years; range, 22-96 years) with solitary HCC less than or equal to 5 cm not amenable to percutaneous ablation who underwent RS (dose of >190 Gy) between 2003 and 2016. Patients who underwent subsequent curative liver transplantation were excluded to eliminate this confounding variable affecting survival. Radiologic response of time to progression and median overall survival were estimated by using the Kaplan-Meier method per the guidelines of the European Association for the Study of the Liver (EASL) and the World Health Organization (WHO). Results Seventy patients were treated with RS over 14 years. Sixty-three patients (90%) showed response by using EASL criteria, of which 41 (59%) showed complete response. Fifty patients (71%) achieved response by using WHO criteria, of which 11 (16%) achieved complete response. Response rates at 6 months were 86% and 49% by using EASL and WHO criteria, respectively. Median time to progression was 2.4 years (95% confidence interval: 2.1, 5.7), with 72% of patients having no target lesion progression at 5 years. Median overall survival was 6.7 years (95% confidence interval: 3.1, 6.7); survival probability at 1, 3, and 5 years was 98%, 66%, and 57%, respectively. Overall survival probability at 1, 3, and 5 years was 100%, 82%, and 75%, respectively, in patients with baseline tumor size less than or equal to 3 cm (n = 45) and was significantly longer than in patients with tumors greater than 3 cm (P = .026). Conclusion RS provides response rates, tumor control, and survival outcomes comparable to curative-intent treatments for selected patients with early-stage HCC who have preserved liver function. © RSNA, 2018 Online supplemental material is available for this article.

PMID: 29688155 [PubMed - as supplied by publisher]



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Use of Myocardial T1 Mapping at 3.0 T to Differentiate Anderson-Fabry Disease from Hypertrophic Cardiomyopathy.

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Use of Myocardial T1 Mapping at 3.0 T to Differentiate Anderson-Fabry Disease from Hypertrophic Cardiomyopathy.

Radiology. 2018 Apr 24;:172613

Authors: Karur GR, Robison S, Iwanochko RM, Morel CF, Crean AM, Thavendiranathan P, Nguyen ET, Mathur S, Wasim S, Hanneman K

Abstract
Purpose To compare left ventricular (LV) and right ventricular (RV) 3.0-T cardiac magnetic resonance (MR) imaging T1 values in Anderson-Fabry disease (AFD) and hypertrophic cardiomyopathy (HCM) and evaluate the diagnostic value of native T1 values beyond age, sex, and conventional imaging features. Materials and Methods For this prospective study, 30 patients with gene-positive AFD (37% male; mean age ± standard deviation, 45.0 years ± 14.1) and 30 patients with HCM (57% male; mean age, 49.3 years ± 13.5) were prospectively recruited between June 2016 and September 2017 to undergo cardiac MR imaging T1 mapping with a modified Look-Locker inversion recovery (MOLLI) acquisition scheme at 3.0 T (repetition time msec/echo time msec, 280/1.12; section thickness, 8 mm). LV and RV T1 values were evaluated. Statistical analysis included independent samples t test, receiver operating characteristic curve analysis, multivariable logistic regression, and likelihood ratio test. Results Septal LV, global LV, and RV native T1 values were significantly lower in AFD compared with those in HCM (1161 msec ± 47 vs 1296 msec ± 55, respectively [P < .001]; 1192 msec ± 52 vs 1268 msec ± 55 [P < .001]; and 1221 msec ± 54 vs 1271 msec ± 37 [P = .001], respectively). A septal LV native T1 cutoff point of 1220 msec or lower distinguished AFD from HCM with sensitivity of 97%, specificity of 93%, and accuracy of 95%. Septal LV native T1 values differentiated AFD from HCM after adjustment for age, sex, and conventional imaging features (odds ratio, 0.94; 95% confidence interval: 0.91, 0.98; P = < .001). In a nested logistic regression model with age, sex, and conventional imaging features, model fit was significantly improved by the addition of septal LV native T1 values (χ2 [df = 1] = 33.4; P < .001). Conclusion Cardiac MR imaging native T1 values at 3.0 T are significantly lower in patients with AFD compared with those with HCM and provide independent and incremental diagnostic value beyond age, sex, and conventional imaging features. © RSNA, 2018.

PMID: 29688154 [PubMed - as supplied by publisher]



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Medium or Large Hepatocellular Carcinoma: Sorafenib Combined with Transarterial Chemoembolization and Radiofrequency Ablation.

Related Articles

Medium or Large Hepatocellular Carcinoma: Sorafenib Combined with Transarterial Chemoembolization and Radiofrequency Ablation.

Radiology. 2018 Apr 24;:172028

Authors: Zhu K, Huang J, Lai L, Huang W, Cai M, Zhou J, Guo Y, Chen J

Abstract
Purpose To determine the safety and efficacy of sorafenib combined with transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) (hereafter, S-TACE-RFA) in patients with medium or large (range, 3.1-7.0 cm in diameter) hepatocellular carcinoma (HCC). Materials and Methods This retrospective study evaluated the medical records of consecutive patients with medium or large HCC who underwent S-TACE-RFA or combined TACE and RFA (hereafter, TACE-RFA) from January 2010 to December 2014. Sorafenib was started 3-5 days after TACE, and RFA was performed 1-2 weeks after TACE. Treatment complications, recurrence-free survival (RFS), and overall survival (OS) in patients who underwent S-TACE-RFA were compared with those in patients who underwent TACE-RFA. Results Of the 174 patients who underwent S-TACE-RFA or TACE-RFA, 106 who met the eligibility criteria were included in this study. Among them, 40 underwent S-TACE-RFA and 66 underwent TACE-RFA. The patients who underwent S-TACE-RFA had longer RFS (median, 24.0 vs 10.0 months; P = .04) and better OS (median, 63.0 vs 36.0 months, P = .048) than those who underwent TACE-RFA. S-TACE-RFA and α-fetoprotein level were independent prognostic factors for survival in uni- and multivariable analyses. The rate of complications in patients who underwent S-TACE-RFA was similar to that in patients who underwent TACE-RFA (22.5% vs 18.2%, P = .59). Conclusion S-TACE-RFA resulted in longer RFS and better OS than did TACE-RFA in patients with medium or large HCC. © RSNA, 2018 Online supplemental material is available for this article.

PMID: 29688153 [PubMed - as supplied by publisher]



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Freiburg Neuropathology Case Conference



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Improvement of region of interest extraction and scanning method of computer-aided diagnosis system for osteoporosis using panoramic radiographs

Abstract

Objectives

Patients undergoing osteoporosis treatment benefit greatly from early detection. We previously developed a computer-aided diagnosis (CAD) system to identify osteoporosis using panoramic radiographs. However, the region of interest (ROI) was relatively small, and the method to select suitable ROIs was labor-intensive. This study aimed to expand the ROI and perform semi-automatized extraction of ROIs. The diagnostic performance and operating time were also assessed.

Methods

We used panoramic radiographs and skeletal bone mineral density data of 200 postmenopausal women. Using the reference point that we defined by averaging 100 panoramic images as the lower mandibular border under the mental foramen, a 400 × 100-pixel ROI was automatically extracted and divided into four 100 × 100-pixel blocks. Valid blocks were analyzed using program 1, which examined each block separately, and program 2, which divided the blocks into smaller segments and performed scans/analyses across blocks. Diagnostic performance was evaluated using another set of 100 panoramic images.

Results

Most ROIs (97.0%) were correctly extracted. The operation time decreased to 51.4% for program 1 and to 69.3% for program 2. The sensitivity, specificity, and accuracy for identifying osteoporosis were 84.0, 68.0, and 72.0% for program 1 and 92.0, 62.7, and 70.0% for program 2, respectively. Compared with the previous conventional system, program 2 recorded a slightly higher sensitivity, although it occasionally also elicited false positives.

Conclusions

Patients at risk for osteoporosis can be identified more rapidly using this new CAD system, which may contribute to earlier detection and intervention and improved medical care.



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Imaging features of benign mass lesions in the nasal cavity and paranasal sinuses according to the 2017 WHO classification

Abstract

The World Health Organization (WHO) 2017 classification of head and neck tumors has been just published and has reorganized tumors of the nasal cavity and paranasal sinuses. In this classification, three new entities (seromucinous hamartoma, NUT carcinoma, and biphenotypic sinonasal sarcoma) were included, while the total number of tumors has been reduced by excluding tumors if they did not occur exclusively or predominantly in this region. Among these entities, benign tumors were classified as sinonasal papillomas, respiratory epithelial lesions, salivary gland tumors, benign soft tissue tumors, or other tumors. In contrast, inflammatory diseases often show tumor-like appearances. The imaging features of these benign tumors and tumor-like inflammatory diseases often resemble malignant tumors, and some benign lesions should be given attention in the follow-up period and before surgery to avoid recurrence, malignant transformation, or massive bleeding. Understanding the CT and MR imaging features of various benign mass lesions is clinically important for appropriate therapy. The purpose of this article is to describe the clinical characteristics and imaging features of each of clinically important nasal and paranasal benign mass lesions, as classified according to the WHO 2017 classification of head and neck tumors, along with some inflammatory diseases.



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Performance of an Automated Versus a Manual Whole-Body Magnetic Resonance Imaging Workflow

Objectives The aim of this study was to evaluate the performance of an automated workflow for whole-body magnetic resonance imaging (WB-MRI), which reduces user interaction compared with the manual WB-MRI workflow. Materials and Methods This prospective study was approved by the local ethics committee. Twenty patients underwent WB-MRI for myopathy evaluation on a 3 T MRI scanner. Ten patients (7 women; age, 52 ± 13 years; body weight, 69.9 ± 13.3 kg; height, 173 ± 9.3 cm; body mass index, 23.2 ± 3.0) were examined with a prototypical automated WB-MRI workflow, which automatically segments the whole body, and 10 patients (6 women; age, 35.9 ± 12.4 years; body weight, 72 ± 21 kg; height, 169.2 ± 10.4 cm; body mass index, 24.9 ± 5.6) with a manual scan. Overall image quality (IQ; 5-point scale: 5, excellent; 1, poor) and coverage of the study volume were assessed by 2 readers for each sequence (coronal T2-weighted turbo inversion recovery magnitude [TIRM] and axial contrast-enhanced T1-weighted [ce-T1w] gradient dual-echo sequence). Interreader agreement was evaluated with intraclass correlation coefficients. Examination time, number of user interactions, and MR technicians' acceptance rating (1, highest; 10, lowest) was compared between both groups. Results Total examination time was significantly shorter for automated WB-MRI workflow versus manual WB-MRI workflow (30.0 ± 4.2 vs 41.5 ± 3.4 minutes, P

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Application of induced pluripotency in cancer studies

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Publication date: May–June 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 3
Author(s): Patrycja Czerwińska, Sylwia Mazurek, Maciej Wiznerowicz
As soon as induced pluripotent stem cells (iPSCs) reprogramming of somatic cells were developed, the discovery attracted the attention of scientists, offering new perspectives for personalized medicine and providing a powerful platform for drug testing. The technology was almost immediately applied to cancer studies. As presented in this review, direct reprogramming of cancer cells with enforced expression of pluripotency factors have several basic purposes, all of which aim to explain the complex nature of cancer development and progression, therapy-resistance and relapse, and ultimately lead to the development of novel anti-cancer therapies. Here, we briefly present recent advances in reprogramming methodologies as well as commonalities between cell reprogramming and carcinogenesis and discuss recent outcomes from the implementation of induced pluripotency into cancer research.



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Performance of an Automated Versus a Manual Whole-Body Magnetic Resonance Imaging Workflow

Objectives The aim of this study was to evaluate the performance of an automated workflow for whole-body magnetic resonance imaging (WB-MRI), which reduces user interaction compared with the manual WB-MRI workflow. Materials and Methods This prospective study was approved by the local ethics committee. Twenty patients underwent WB-MRI for myopathy evaluation on a 3 T MRI scanner. Ten patients (7 women; age, 52 ± 13 years; body weight, 69.9 ± 13.3 kg; height, 173 ± 9.3 cm; body mass index, 23.2 ± 3.0) were examined with a prototypical automated WB-MRI workflow, which automatically segments the whole body, and 10 patients (6 women; age, 35.9 ± 12.4 years; body weight, 72 ± 21 kg; height, 169.2 ± 10.4 cm; body mass index, 24.9 ± 5.6) with a manual scan. Overall image quality (IQ; 5-point scale: 5, excellent; 1, poor) and coverage of the study volume were assessed by 2 readers for each sequence (coronal T2-weighted turbo inversion recovery magnitude [TIRM] and axial contrast-enhanced T1-weighted [ce-T1w] gradient dual-echo sequence). Interreader agreement was evaluated with intraclass correlation coefficients. Examination time, number of user interactions, and MR technicians' acceptance rating (1, highest; 10, lowest) was compared between both groups. Results Total examination time was significantly shorter for automated WB-MRI workflow versus manual WB-MRI workflow (30.0 ± 4.2 vs 41.5 ± 3.4 minutes, P

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Preparation of MnO2 coated fibers for gamma spectrometric measurements - A comparison of four practical approaches

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Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Michael Schubert, Martin Oberreich, Jan Scholten
The analysis of natural radium-in-water activity concentrations is for two reasons of general interest: (1) radium in natural waters may pose a problem with regard to radiation protection and (2) radium isotopes in natural waters can be used as environmental tracers in hydrological studies. A state-of-the-art method for radium extraction from (generally large) water sample volumes is radium adsorption onto MnO2 coated acrylic fibers. In our study we comparatively evaluated four methodical approaches for post-extraction preparation of the fiber to allow gamma spectrometric measurements. The methods included (1) straightforward measurement of the loose fiber, (2) compressing the fiber after mixing it with an adhesive, (3) combustion of the fiber and embedding the ash in candlewax, and (4) leaching of the fiber and embedding the resulting precipitate in candlewax. The aim of the study was to compare the advantages and disadvantages of the four preparation approaches with respect to their individual practicability. Even though the methodical fiber preparation approaches have been suggested in the literature before (as cited in this paper), results of their direct practical comparison have not been presented yet. Our study revealed that balancing practical sample preparation effort against data reproducibility suggests a measurement of the compressed fiber applying an adhesive to be the preferable approach.



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Geochemical signature of NORM waste in Brazilian oil and gas industry

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Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): G.T. De-Paula-Costa, I.C. Guerrante, J. Costa-de-Moura, F.C. Amorim
The Brazilian Nuclear Energy Agency (CNEN) is responsible for any radioactive waste storage and disposal in the country. The storage of radioactive waste is carried out in the facilities under CNEN regulation and its disposal is operated, managed and controlled by the CNEN. Oil NORM (Naturally Occurring Radioactive Materials) in this article refers to waste coming from oil exploitation. Oil NORM has called much attention during the last decades, mostly because it is not possible to determine its primary source due to the actual absence of a regulatory control mechanism. There is no efficient regulatory tool which allows determining the origin of such NORM wastes even among those facilities under regulatory control. This fact may encourage non-authorized radioactive material transportation, smuggling and terrorism. The aim of this project is to provide a geochemical signature for oil NORM waste using its naturally occurring isotopic composition to identify its origin. The here proposed method is the modeling of radioisotopes normally present in oil pipe contamination such as 228Ac, 214Bi and 214Pb analyzed by gamma spectrometry. The specific activities of elements from different decay series are plotted in a scatter diagram. This method was successfully tested with gamma spectrometry analyses of oil sludge NORM samples from four different sources obtained from Petrobras reports for the Campos Basin/Brazil.



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Comparison of experimental and calculated shielding factors for modular buildings in a radioactive fallout scenario

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Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Yvonne Hinrichsen, Robert Finck, Karl Östlund, Christopher Rääf, Kasper Grann Andersson
Experimentally and theoretically determined shielding factors for a common light construction dwelling type were obtained and compared. Sources of the gamma-emitting radionuclides 60Co and 137Cs were positioned around and on top of a modular building to represent homogeneous fallout. The modular building used was a standard prefabricated structure obtained from a commercial manufacturer. Four reference positions for the gamma radiation detectors were used inside the building. Theoretical dose rate calculations were performed using the Monte Carlo code MCNP6, and additional calculations were performed that compared the shielding factor for 137Cs and 134Cs. This work demonstrated the applicability of using MCNP6 for theoretical calculations of radioactive fallout scenarios. Furthermore, the work showed that the shielding effect for modular buildings is almost the same for 134Cs as for 137Cs.



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‘Omic’ technologies as a helpful tool in radioecological research

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Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Polina Yu. Volkova, Stanislav A. Geras'kin
This article presents a brief review of the modern 'omic' technologies, namely genomics, epigenomics, transcriptomics, proteomics, and metabolomics, as well as the examples of their possible use in radioecology. For each technology, a short description of advances, limitations, and instrumental applications is given. In addition, the review contains examples of successful use of 'omic' technologies in the assessment of biological effects of pollutants in the field conditions.



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A survey of uranium levels in urine and hair of people living in a coal mining area in Yili, Xinjiang, China

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Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Rehemanjiang Wufuer, Wenjuan Song, Daoyong Zhang, Xiangliang Pan, Geoffrey Michael Gadd
Recent reports have drawn attention to the uranium contamination arising from coal mining activities in the Yili region of Xinjiang, China due to the mixed distribution of uranium and coal mines, and some of the coal mines being associated with a high uranium content. In this study, we have collected water samples, solid samples such as soil, mud, coal, and coal ash, and hair and urine samples from local populations in order to evaluate the uranium level in this environment and its implications for humans in this high uranium coal mining area. Our results showed that uranium concentrations were 8.71–10.91 μg L−1 in underground water, whereas lower levels of uranium occurred in river water. Among the solid samples, coal ash contained fairly high concentrations of uranium (33.1 μg g−1) due to enrichment from coal burning. In addition, uranium levels in the other solid samples were around 2.8 μg g−1 (the Earth's average background value). Uranium concentrations in hair and urine samples were 22.2–634.5 ng g−1 (mean: 156.2 ng g−1) and 8.44–761.6 ng L−1 (mean: 202.6 ng L−1), respectively, which are significantly higher than reference values reported for unexposed subjects in other areas. Therefore, these results indicate that people living in this coal mining area have been subjected to uranium exposure for long periods of time.



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The 2014 Integrated Field Exercise of the Comprehensive Nuclear-Test-Ban Treaty revisited: The case for data fusion

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Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Jonathan L. Burnett, Harry S. Miley, Theodore W. Bowyer, Ian M. Cameron
The International Monitoring System of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) uses a global network of radionuclide monitoring stations to detect evidence of a nuclear explosion. The two radionuclide technologies employed—particulate and noble gas (radioxenon) detection—have applications for data fusion to improve detection of a nuclear explosion. Using the hypothetical 0.5 kT nuclear explosive test scenario of the CTBTO 2014 Integrated Field Exercise, the intrinsic relationship between particulate and noble gas signatures has been examined. This study shows that, depending upon the time of the radioxenon release, the particulate progeny can produce the more detectable signature. Thus, as both particulate and noble gas signatures are inherently coupled, the authors recommend that the sample categorization schemes should be linked.



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Submarine groundwater discharge and chemical behavior of tracers in Laizhou Bay, China

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Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Yan Zhang, Hailong Li, Xuejing Wang, Chaoyue Wang, Kai Xiao, Wenjing Qu
Naturally occurring radon (222Rn) and radium isotopes are widely used to trace water mixing and submarine groundwater discharge (SGD) in the coastal zones. However, their activities in groundwater are variable both spatially and temporally. Here, time series sampling of 222Rn and radium was conducted to investigate their behavior in intertidal groundwater of Laizhou Bay, China. The result shows that groundwater redox conditions have an important impact on the behavior of tracers. The activities of tracers will decrease under oxidizing conditions and increase under reducing conditions. Radon and radium mass balance models were used to evaluate the flushing time and SGD based on spatial surveys in Laizhou Bay. The flushing time is estimated to be 32.9–55.3 d with coupled models, which agrees well with the result of tidal prism model. The trace-derived SGD in the whole bay ranges from 6.1 × 108 to 9.0 × 108 m3/d and the re-circulated seawater (RSGD) ranges from 5.5 × 108 to 8.5 × 108 m3/d. The average SGD and RSGD fluxes are 22.8 and 21.1 times greater than the Yellow River discharge in April 2014, respectively. The study provides a better understanding of the dynamics of coastal groundwater and behavior of tracers in a well-studied bay system.



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Evaluation of background radiation dose contributions in the United Arab Emirates

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Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Braden Goddard, Emmanuel Bosc, Sarra Al Hasani, Cody Lloyd
The natural background radiation consists of three main components; cosmic, terrestrial, and skyshine. Although there are currently methods available to measure the total dose rate from background radiation, no established methods exist that allow for the measurement of each component the background radiation. This analysis consists of a unique methodology in which the dose rate contribution from each component of the natural background radiation is measured and calculated. This project evaluates the natural background dose rate in the Abu Dhabi City region from all three of these components using the developed methodology. Evaluating and understanding the different components of background radiation provides a baseline allowing for the detection, and possibly attribution, of elevated radiation levels. Measurements using a high-pressure ion chamber with different shielding configurations and two offshore measurements provided dose rate information that were attributed to the different components of the background radiation. Additional spectral information was obtained using an HPGe detector to verify and quantify the presence of terrestrial radionuclides. By evaluating the dose rates of the different shielding configurations the comic, terrestrial, and skyshine contribution in the Abu Dhabi City region were determined to be 33.0 ± 1.7, 15.7 ± 2.5, and 2.4 ± 2.1 nSv/h, respectively.



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Characterizing regional-scale temporal evolution of air dose rates after the Fukushima Daiichi Nuclear Power Plant accident

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Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Haruko M. Wainwright, Akiyuki Seki, Satoshi Mikami, Kimiaki Saito
In this study, we quantify the temporal changes of air dose rates in the regional scale around the Fukushima Dai-ichi Nuclear Power Plant in Japan, and predict the spatial distribution of air dose rates in the future. We first apply the Bayesian geostatistical method developed by Wainwright et al. (2017) to integrate multiscale datasets including ground-based walk and car surveys, and airborne surveys, all of which have different scales, resolutions, spatial coverage, and accuracy. This method is based on geostatistics to represent spatial heterogeneous structures, and also on Bayesian hierarchical models to integrate multiscale, multi-type datasets in a consistent manner. We apply this method to the datasets from three years: 2014 to 2016. The temporal changes among the three integrated maps enables us to characterize the spatiotemporal dynamics of radiation air dose rates. The data-driven ecological decay model is then coupled with the integrated map to predict future dose rates. Results show that the air dose rates are decreasing consistently across the region. While slower in the forested region, the decrease is particularly significant in the town area. The decontamination has contributed to significant reduction of air dose rates. By 2026, the air dose rates will continue to decrease, and the area above 3.8 μSv/h will be almost fully contained within the non-residential forested zone.



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Method for source localization proposed and applied to the October 2017 case of atmospheric dispersion of Ru-106

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Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Jens Havskov Sørensen
An efficient numerical method for the temporal and spatial localization of an unknown point source of an atmospheric tracer is proposed. The method, which is based on inverse modelling techniques, employs available data from a network of ground-level stations on the condition that the measurements represent the plume geographically and temporally. The method, which employs a level-of-agreement approach, is applied to the October 2017 air concentration measurements of Ru-106 in Europe.



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Τρίτη, 24 Απριλίου 2018

Occurrence and associated factors of carotid artery calcification detected by digital panoramic radiography in chronic kidney disease patients undergoing hemodialysis

To investigate the occurrence and associated factors of carotid artery calcification (CAC) in chronic kidney disease (CKD) patients undergoing hemodialysis.

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Automatic quantification of calcifications in the coronary arteries and thoracic aorta on radiotherapy planning CT scans of Western and Asian breast cancer patients

This study automatically quantified calcifications in coronary arteries (CAC) and thoracic aorta (TAC) on breast planning computed tomography (CT) scans and assessed its reproducibility compared to manual scoring.

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Heart volume reduction during radiotherapy involving the thoracic region in children: An unexplained phenomenon

Radiotherapy involving the thoracic region is associated with cardiotoxicity in long-term childhood cancer survivors. We quantified heart volume changes during radiotherapy in children (<18 years) and investigated correlations with patient and treatment related characteristics.

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Improving the modelling of irradiation-induced brain activation for in vivo PET verification of proton therapy

A reliable Monte Carlo prediction of proton-induced brain tissue activation used for comparison to particle therapy positron-emission-tomography (PT-PET) measurements is crucial for in vivo treatment verification. Major limitations of current approaches to overcome include the CT-based patient model and the description of activity washout due to tissue perfusion.

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A long-awaited guideline for the delineation of primary tumor in head and neck cancer, and a few concerns about it

We read the article entitled 'Delineation of the primary tumour Clinical Target Volumes (CTV-P) in laryngeal, hypopharyngeal, oropharyngeal and oral cavity squamous cell carcinoma: AIRO, CACA, DAHANCA, EORTC, GEORCC, GORTEC, HKNPCSG, HNCIG, IAG-KHT, LPRHHT, NCIC CTG, NCRI, NRG Oncology, PHNS, SBRT, SOMERA, SRO, SSHNO, TROG consensus guidelines' with great interest [1]. There was a lack of a guideline for the delineation of the primary tumor in head and neck cancer. This paper might shed light on the accurate delineation the clinical target volume (CTV).

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Efficacy of thoracic radiotherapy in patients with stage IIIB–IV epidermal growth factor receptor-mutant lung adenocarcinomas who received and responded to tyrosine kinase inhibitor treatment

Large-scale, prospective, randomized studies of the efficacy of thoracic radiotherapy (RT) in patients with unresectable stage IIIB–IV epidermal growth factor receptor (EGFR)-mutant lung adenocarcinomas who received and responded to EGFR tyrosine kinase inhibitor (TKI) treatment are not currently available. Therefore, we designed a propensity score-matched, nationwide, population-based, cohort study for estimating the effects of thoracic RT on patients with EGFR-mutant lung adenocarcinomas.

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Overview of research and therapy facilities for radiobiological experimental work in particle therapy. Report from the European Particle Therapy Network radiobiology group

Particle therapy (PT) as cancer treatment, using protons or heavier ions, can provide a more favorable dose distribution compared to X-rays. While the physical characteristics of particle radiation have been the aim of intense research, less focus has been placed on the actual biological responses arising from particle irradiation.One of the biggest challenges for proton radiobiology is the RBE, with an increasing concern that the clinically-applied generic RBE-value of 1.1 is an approximation, as RBE is a complex quantity, depending on both biological and physical parameters, such as dose, LET, cellular and tissue radiobiological characteristics, as well as the endpoints being studied.

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Preoperative Digital Subtraction Angiography in Incidental Unruptured Intracranial Aneurysms

Abstract

Purpose

Digital subtraction angiography (DSA) is deemed necessary to precisely visualize intracranial aneurysms and define individual treatment strategies. In patients with unruptured intracranial aneurysms (UIA) who were diagnosed by MRI, a four-vessel DSA is usually performed to detect additional aneurysms. This study aimed to evaluate whether the evaluation of all vessels beyond the aneurysm-harboring artery is really necessary.

Material and methods

Patients with an UIA that was detected on MRA (TOF/ceMRA) were prospectively included. All patients underwent a four-vessel DSA (including 3D-DSA) and two experienced neuroradiologists independently analyzed the MRI sequences before DSA. The number of aneurysms, size and anatomic localization were documented and correlated with the angiographic findings.

Results

The DSA revealed a total of 134 aneurysms in 106 patients. Overall sensitivity and negative predictive value of MRA were 95.6% and 95.6%, respectively. In patients with multiple (≥2) aneurysms, 4 very small aneurysms <3 mm in the A2 segment, posterior communicating artery (PcomA), extradural internal carotid artery (ICA) were missed with MRI alone. In one patient with an ICA aneurysm, an additional small MCA bifurcation aneurysm was overlooked by MRA but detected by DSA. The periprocedural complication rate was 0.9%.

Conclusion

The rate of aneurysms that were detected by DSA but not by MRA was very low, thus potentially justifying visualization of the vessel harboring aneurysm alone; however, the four-vessel angiography detected further small aneurysms in patients with multiple aneurysms and therefore seems to be indicated in this specific subgroup. This approach has the potential to reduce the risk of complications, the intervention time and thus radiation exposure.



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American Thyroid Association Scientific Statement on the Use of Potassium Iodide Ingestion in a Nuclear Emergency.

Related Articles

American Thyroid Association Scientific Statement on the Use of Potassium Iodide Ingestion in a Nuclear Emergency.

Thyroid. 2017 Jul;27(7):865-877

Authors: Leung AM, Bauer AJ, Benvenga S, Brenner AV, Hennessey JV, Hurley JR, Milan SA, Schneider AB, Sundaram K, Toft DJ

Abstract
This document serves to summarize the issues and the American Thyroid Association (ATA) position regarding the use of potassium iodide as a thyroid blocking agent in the event of a nuclear accident. The purpose is to provide a review and updated position statement regarding the advanced distribution, stockpiling, and availability of potassium iodide in the event of nuclear radiation emergencies in the United States.

PMID: 28537500 [PubMed - indexed for MEDLINE]



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Micro-CT study of the human cochlear aqueduct.

Related Articles

Micro-CT study of the human cochlear aqueduct.

Surg Radiol Anat. 2018 Apr 21;:

Authors: Li Z, Shi D, Li H, Tan S, Liu Y, Qi C, Tang A

Abstract
OBJECTIVE: The anatomic structure of the cochlear aqueduct (CA) in human temporal bone specimens was observed using micro-computed tomography (CT).
MATERIALS AND METHODS: Micro-CT scanning of 18-µm-thick slices was performed on 30 slides of human temporal bone specimens to observe the CA structure and its relationship with its surroundings. The length, internal and external apertures, and the narrowest width of the CA were measured. The differences in CAs were compared between high jugular bulb (HJB) specimens and normal specimens.
RESULTS: A large number of CA images were acquired using Micro-CT scanning, which clearly displayed the basic anatomic structures, stereotactic localizations, and adjacent relationships of the CAs. The whole course of a CA was 12.31 ± 3.60 mm, the diameter of the internal aperture was 465 ± 242 µm, the diameter of the external aperture was 2.88 ± 1.06 mm, the narrowest diameter was 601 ± 335 µm, the diameter of the opening of inferior cochlear vein (ICV) was 151 ± 50 µm, the distance between the internal aperture and ICV was 270 ± 197 µm, and the distance between the inferior margin of the internal acoustic meatus (IAM) and the top most part of the external aperture of the CA was 6.783 ± 2.15 mm. No bony obstruction of the CA or CA enlargement was observed in the specimens. A total of 28 CAs had one accompanying bony canal in the surroundings. The length and travelling of the CA were not affected by the level of the jugular bulb (JB). The variation of the travelling of the ICV was larger than that of the CA.
CONCLUSION: Micro-CT adequately displayed the bony CA canal and provided a new method for anatomical studies of the CA and a basis for functional studies.

PMID: 29680956 [PubMed - as supplied by publisher]



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A first-in-man PET study of [ 18 F]PSS232, a fluorinated ABP688 derivative for imaging metabotropic glutamate receptor subtype 5

Abstract

Purpose

Non-invasive imaging of metabotropic glutamate receptor 5 (mGlu5) in the brain using PET is of interest in e.g., anxiety, depression, and Parkinson's disease. Widespread application of the most widely used mGlu5 tracer, [11C]ABP688, is limited by the short physical half-life of carbon-11. [18F]PSS232 is a fluorinated analog with promising preclinical properties and high selectivity and specificity for mGlu5. In this first-in-man study, we evaluated the brain uptake pattern and kinetics of [18F]PSS232 in healthy volunteers.

Methods

[18F]PSS232 PET was performed with ten healthy male volunteers aged 20–40 years. Seven of the subjects received a bolus injection and the remainder a bolus/infusion protocol. Cerebral blood flow was determined in seven subjects using [15O]water PET. Arterial blood activity was measured using an online blood counter. Tracer kinetics were evaluated by compartment modeling and parametric maps were generated for both tracers.

Results

At 90 min post-injection, 59.2 ± 11.1% of total radioactivity in plasma corresponded to intact tracer. The regional first pass extraction fraction of [18F]PSS232 ranged from 0.41 ± 0.06 to 0.55 ± 0.03 and brain distribution pattern matched that of [11C]ABP688. Uptake kinetics followed a simple two-tissue compartment model. The volume of distribution of total tracer (V T, ml/cm3) ranged from 1.18 ± 0.20 for white matter to 2.91 ± 0.51 for putamen. The respective mean distribution volume ratios (DVR) with cerebellum as the reference tissue were 0.88 ± 0.06 and 2.12 ± 0.10, respectively. The tissue/cerebellum ratios of a bolus/infusion protocol (30/70 dose ratio) were close to the DVR values.

Conclusions

Brain uptake of [18F]PSS232 matched the distribution of mGlu5 and followed a two-tissue compartment model. The well-defined kinetics and the possibility to use reference tissue models, obviating the need for arterial blood sampling, make [18F]PSS232 a promising fluorine-18 labeled radioligand for measuring mGlu5 density in humans.



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Extraction, selection and comparison of features for an effective automated computer-aided diagnosis of Parkinson’s disease based on [ 123 I]FP-CIT SPECT images

Abstract

Purpose

This work aimed to assess the potential of a set of features extracted from [123I]FP-CIT SPECT brain images to be used in the computer-aided "in vivo" confirmation of dopaminergic degeneration and therefore to assist clinical decision to diagnose Parkinson's disease.

Methods

Seven features were computed from each brain hemisphere: five standard features related to uptake ratios on the striatum and two features related to the estimated volume and length of the striatal region with normal uptake. The features were tested on a dataset of 652 [123I]FP-CIT SPECT brain images from the Parkinson's Progression Markers Initiative. The discrimination capacities of each feature individually and groups of features were assessed using three different machine learning techniques: support vector machines (SVM), k-nearest neighbors and logistic regression.

Results

Cross-validation results based on SVM have shown that, individually, the features that generated the highest accuracies were the length of the striatal region (96.5%), the putaminal binding potential (95.4%) and the striatal binding potential (93.9%) with no statistically significant differences among them. The highest classification accuracy was obtained using all features simultaneously (accuracy 97.9%, sensitivity 98% and specificity 97.6%). Generally, slightly better results were obtained using the SVM with no statistically significant difference to the other classifiers for most of the features.

Conclusions

The length of the striatal region uptake is clinically useful and highly valuable to confirm dopaminergic degeneration "in vivo" as an aid to the diagnosis of Parkinson's disease. It compares fairly well to the standard uptake ratio-based features, reaching, at least, similar accuracies and is easier to obtain automatically. Thus, we propose its day to day clinical use, jointly with the uptake ratio-based features, in the computer-aided diagnosis of dopaminergic degeneration in Parkinson's disease.



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Correction to: Biological tumour volumes of gliomas in early and standard 20–40 min 18 F-FET PET images differ according to IDH mutation status

Abstract

The name of M. Unterrainer was inadvertently presented as M. Unterrrainer in the original article.



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PSA-stratified detection rates for [ 68 Ga]THP-PSMA, a novel probe for rapid kit-based 68 Ga-labeling and PET imaging, in patients with biochemical recurrence after primary therapy for prostate cancer

Abstract

Purpose

[68Ga]Tris(hydroxypyridinone)(THP)-PSMA is a novel radiopharmaceutical for one-step kit-based radiolabelling, based on direct chelation of 68Ga3+ at low concentration, room temperature and over a wide pH range, using direct elution from a 68Ge/68Ga-generator. We evaluated the clinical detection rates of [68Ga]THP-PSMA PET/CT in patients with biochemically recurrent prostate cancer after prostatectomy.

Methods

Consecutive patients (n=99) referred for evaluation of biochemical relapse of prostate cancer by [68Ga]THP-PSMA PET/CT were analyzed retrospectively. Patients underwent a standard whole-body PET/CT (1 h p.i.), followed by delayed (3 h p.i.) imaging of the abdomen. PSA-stratified cohorts of positive PET/CT results, standardized uptake values (SUVs) and target-to-background ratios (TBRs) were analyzed, and compared between standard and delayed imaging.

Results

At least one lesion suggestive of recurrent or metastatic prostate cancer was identified on PET images in 52 patients (52.5%). Detection rates of [68Ga]THP-PSMA PET/CT increased with increasing PSA level: 94.1% for a PSA value of ≥10 ng/mL, 77.3% for a PSA value of 2 to <10 ng/mL, 54.5% for a PSA value of 1 to <2 ng/mL, 14.3% for a PSA value of 0.5 to <1 ng/mL, 20.0% for a PSA value of >0.2 to <0.5, and 22.2% for a PSA value of 0.01 to 0.2 ng/mL. [68Ga]THP-PSMA uptake (SUVs) in metastases decreased over time, whereas TBRs improved. Delayed imaging at 3 h p.i. exclusively identified pathologic findings in 2% of [68Ga]THP-PSMA PET/CT scans. Detection rate was higher in patients with a Gleason score ≥8 (P=0.02) and in patients receiving androgen deprivation therapy (P=0.003).

Conclusions

In this study, [68Ga]THP-PSMA PET/CT showed suitable detection rates in patients with biochemical recurrence of prostate cancer and PSA levels ≥ 2 ng /mL. Detections rates were lower than in previous studies evaluating other PSMA ligands, though prospective direct radiotracer comparison studies are mandatory particularly in patients with low PSA levels to evaluate the relative performance of different PSMA ligands.



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11 C–acetate PET/CT: a potential alternative of transcranial biopsy for grading cerebral gliomas



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Hybrid MR-PET of brain tumours using amino acid PET and chemical exchange saturation transfer MRI

Abstract

Purpose

PET using radiolabelled amino acids has become a promising tool in the diagnostics of gliomas and brain metastasis. Current research is focused on the evaluation of amide proton transfer (APT) chemical exchange saturation transfer (CEST) MR imaging for brain tumour imaging. In this hybrid MR-PET study, brain tumours were compared using 3D data derived from APT-CEST MRI and amino acid PET using O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET).

Methods

Eight patients with gliomas were investigated simultaneously with 18F-FET PET and APT-CEST MRI using a 3-T MR-BrainPET scanner. CEST imaging was based on a steady-state approach using a B1 average power of 1μT. B0 field inhomogeneities were corrected a Prametric images of magnetisation transfer ratio asymmetry (MTRasym) and differences to the extrapolated semi-solid magnetisation transfer reference method, APT# and nuclear Overhauser effect (NOE#), were calculated. Statistical analysis of the tumour-to-brain ratio of the CEST data was performed against PET data using the non-parametric Wilcoxon test.

Results

A tumour-to-brain ratio derived from APT# and 18F-FET presented no significant differences, and no correlation was found between APT# and 18F-FET PET data. The distance between local hot spot APT# and 18F-FET were different (average 20 ± 13 mm, range 4–45 mm).

Conclusion

For the first time, CEST images were compared with 18F-FET in a simultaneous MR-PET measurement. Imaging findings derived from18F-FET PET and APT CEST MRI seem to provide different biological information. The validation of these imaging findings by histological confirmation is necessary, ideally using stereotactic biopsy.



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Investigation of receptor radionuclide therapy with 177 Lu-DOTATATE in patients with GEP-NEN and a high Ki-67 proliferation index

Abstract

Purpose

In the 2010 WHO classification, a Ki-67 proliferation index of 20% is the cut-off between intermediate-grade and high-grade gastroenteropancreatic neuroendocrine neoplasia (GEP-NEN). However, in clinical practice, tumours with a Ki-67 index of >15% are often considered high grade and treated with chemotherapy. In 40–70% of high-grade NENs, somatostatin receptors are overexpressed, enabling peptide receptor radionuclide therapy (PRRT) to be performed. We investigated the role of PRRT with 177Lu-DOTATATE in patients with GEP-NEN and a high Ki-67 proliferation index.

Methods

A total of 33 patients with advanced GEP-NENs, positive somatostatin receptor imaging (SRI+) and a Ki-67 proliferation index ranging from 15% to 70% were treated with Lu-PRRT. A cumulative activity of 18.5 GBq or 27.8 GBq of 177Lu-DOTATATE was administered in four or five cycles. Receiver operating characteristic (ROC) curve analysis was used to determine the best threshold of Ki-67 expression to predict disease progression.

Results

All patients completed the intended treatment. The median follow-up was 43 months (range 3–69 months). Two patients (6%) achieved a partial response and 21 (64%) showed stable disease, giving a disease control rate (DCR) of 70%. The median progression-free survival (PFS) was 23 months (95% CI 14.9–31.0 months) and the median overall survival was 52.9 months (95% CI 17.1–68.9 months). ROC curve analysis at 23 months revealed that the best Ki-67 index cut-off was 35%. In 23 patients (70%) the Ki-67 index was ≤35% and in 10 patients (30%) the Ki-67 index was in the range 36–70%. The DCR in the former group was 87% and 30% in the latter. The median PFS was 26.3 months (95% CI 18.4–37.7 months) and 6.8 months (95% CI 2.1–27 months), respectively (p = 0.005).

Conclusions

Lu-PRRT showed antitumour activity in SRI+ GEP-NENs of intermediate and high-grade. DCR and PFS were significantly better in patients with a Ki-67 index of ≤35% than in those with a Ki-67 index of >35%. On the basis of these results, PRRT should be considered as a therapeutic option in patients with high-grade SRI+ GEP-NENs, in particular those with a Ki-67 proliferation index of ≤35%.



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Combined model-based and patient-specific dosimetry for 18 F-DCFPyL, a PSMA-targeted PET agent

Abstract

Purpose

Prostate-specific membrane antigen (PSMA), a type-II integral membrane protein highly expressed in prostate cancer, has been extensively used as a target for imaging and therapy. Among the available PET radiotracers, the low molecular weight agents that bind to PSMA are proving particularly effective. We present the dosimetry results for 18F-DCFPyL in nine patients with metastatic prostate cancer.

Methods

Nine patients were imaged using sequential PET/CT scans at approximately 1, 12, 35 and 70 min, and a final PET/CT scan at approximately 120 min after intravenous administration of 321 ± 8 MBq (8.7 ± 0.2 mCi) of18F-DCFPyL. Time-integrated-activity coefficients were calculated and used as input in OLINDA/EXM software to obtain dose estimates for the majority of the major organs. The absorbed doses (AD) to the eye lens and lacrimal glands were calculated using Monte-Carlo models based on idealized anatomy combined with patient-specific volumes and activity from the PET/CT scans. Monte-Carlo based models were also developed for calculation of the dose to two major salivary glands (parotid and submandibular) using CT-based patient-specific gland volumes.

Results

The highest calculated mean AD per unit administered activity of 18F was found in the lacrimal glands, followed by the submandibular glands, kidneys, urinary bladder wall, and parotid glands. The S-values for the lacrimal glands to the eye lens (0.42 mGy/MBq h), the tear film to the eye lens (1.78 mGy/MBq h) and the lacrimal gland self-dose (574.10 mGy/MBq h) were calculated. Average S-values for the salivary glands were 3.58 mGy/MBq h for the parotid self-dose and 6.78 mGy/MBq h for the submandibular self-dose. The resultant mean effective dose of 18F-DCFPyL was 0.017 ± 0.002 mSv/MBq.

Conclusions

18F-DCFPyL dosimetry in nine patients was obtained using novel models for the lacrimal and salivary glands, two organs with potentially dose-limiting uptake for therapy and diagnosis which lacked pre-existing models.



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The roles of 11 C-acetate PET/CT in predicting tumor differentiation and survival in patients with cerebral glioma

Abstract

Purpose

This prospective study aimed to evaluate the clinical values of 11C–acetate positron emission tomography/computed tomography (PET/CT) in predicting histologic grades and survival in patients with cerebral glioma.

Methods

Seventy-three patients with surgically confirmed cerebral gliomas (19 grade II, 21 grade III, and 33 grade IV) who underwent 11C–acetate PET/CT before surgery were included. Tumor-to-choroid plexus ratio (TCR), which was defined as the maximum standardized uptake value (SUV) of tumors to the mean SUV of choroid plexus, was compared between three World Health Organization (WHO) grade groups. Moreover, metabolic tumor volumes (MTV) were calculated. Progression-free survival (PFS) and overall survival (OS) curves were plotted using the Kaplan–Meier method, and differences in survival between groups were assessed using the log-rank test.

Results

Median TCR was 1.20 (interquartile range [IQR], 1.14 to 1.4) in grade II, 1.65 (IQR, 1.26 to 1.79) in grade III, and 2.53 (IQR, 1.93 to 3.30) in grade IV gliomas. Significant differences in TCR were seen among the three WHO grade groups (P < 0.001). In Cox regression analysis including TCR, MTV, molecular markers, and other clinical factors, TCR was prognostic for PFS (P = 0.016) and TCR and MTV were prognostic for OS (P = 0.024 [TCR], P = 0.030 [MTV]). PFS and OS were significantly shorter in patients with a TCR ≥ 1.6 than in those with a TCR < 1.6. OS were significantly shorter in patients with a MTV ≥ 1 than in those with a TCR < 1.

Conclusions

TCR on 11C–acetate PET/CT significantly differed between low- and high-grade cerebral gliomas, and it showed the capability to further differentiate grade III from grade IV tumors. TCR and MTV were independent prognostic factors and predicted survival better than did the WHO grade.



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Advantage of 18 F-PSMA-1007 over 68 Ga-PSMA-11 PET imaging for differentiation of local recurrence vs. urinary tracer excretion



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68 Ga-PSMA PET/CT in the evaluation of bone metastases in prostate cancer

Abstract

Purpose

The aims of this retrospective analysis were to compare 68Ga-PSMA PET findings and low-dose CT findings (120 kV, 30 mA), and to obtain semiquantitative and quantitative 68Ga-PSMA PET data in patients with prostate cancer (PC) bone metastases.

Methods

In total, 152 PET/CT scans from 140 patients were evaluated. Of these patients, 30 had previously untreated primary PC, and 110 had biochemical relapse after treatment of primary PC. All patients underwent dynamic PET/CT scanning of the pelvis and lower abdomen as well as whole-body PET/CT with 68Ga-PSMA-11. The PET/CT scans were analysed qualitatively (visually), semiquantitatively (SUV), and quantitatively based on a two-tissue compartment model and a noncompartmental approach leading to the extraction of the fractal dimension. Differences were considered significant for p values <0.05.

Results

In total, 168 68Ga-PSMA-positive and 113 CT-positive skeletal lesions were detected in 37 patients (8 with primary PC, 29 with biochemical recurrence). Of these 168 lesions, 103 were both 68Ga-PSMA PET-positive and CT-positive, 65 were only 68Ga-PSMA-positive, and 10 were only CT-positive. The Yang test showed that there were significantly more 68Ga-PSMA PET-positive lesions than CT-positive lesions. Association analysis showed that PSA plasma levels were significantly correlated with several 68Ga-PSMA-11-associated parameters in bone metastases, including the degree of tracer uptake (SUVaverage and SUVmax), its transport rate from plasma to the interstitial/intracellular compartment (K1), its rate of binding to the PSMA receptor and its internalization (k3), its influx rate (Ki), and its distribution heterogeneity.

Conclusion

68Ga-PSMA PET/CT is a useful diagnostic tool in the detection of bone metastases in PC. 68Ga-PSMA PET visualizes more bone metastases than low-dose CT. PSA plasma levels are significantly correlated with several 68Ga-PSMA PET parameters.



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Amyloid and tau signatures of brain metabolic decline in preclinical Alzheimer’s disease

Abstract

Purpose

We aimed to determine the amyloid (Aβ) and tau biomarker levels associated with imminent Alzheimer's disease (AD) - related metabolic decline in cognitively normal individuals.

Methods

A threshold analysis was performed in 120 cognitively normal elderly individuals by modelling 2-year declines in brain glucose metabolism measured with [18F]fluorodeoxyglucose ([18F]FDG) as a function of [18F]florbetapir Aβ positron emission tomography (PET) and cerebrospinal fluid phosphorylated tau biomarker thresholds. Additionally, using a novel voxel-wise analytical framework, we determined the sample sizes needed to test an estimated 25% drugeffect with 80% of power on changes in FDG uptake over 2 years at every brain voxel.

Results

The combination of [18F]florbetapir standardized uptake value ratios and phosphorylated-tau levels more than one standard deviation higher than their respective thresholds for biomarker abnormality was the best predictor of metabolic decline in individuals with preclinical AD. We also found that a clinical trial using these thresholds would require as few as 100 individuals to test a 25% drug effect on AD-related metabolic decline over 2 years.

Conclusions

These results highlight the new concept that combined Aβ and tau thresholds can predict imminent neurodegeneration as an alternative framework with a high statistical power for testing the effect of disease-modifying therapies on [18F]FDG uptake decline over a typical 2-year clinical trial period in individuals with preclinical AD.



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Imaging α v β 3 integrin expression in skeletal metastases with 99m Tc-maraciclatide single-photon emission computed tomography: detection and therapy response assessment

Abstract

Purpose

Osteoclast activity is an important factor in the pathogenesis of skeletal metastases and is a potential therapeutic target. This study aimed to determine if selective uptake of 99mTc-maraciclatide, a radiopharmaceutical targeting αvβ3 integrin, occurs in prostate cancer (PCa) bone metastases and to observe the changes following systemic therapy.

Methods

The study group comprised 17 men with bone-predominant metastatic PCa who underwent whole-body planar and single-photon emission computed tomography/computed tomography (SPECT/CT) imaging with 99mTc-maraciclatide before (n = 17) and 12 weeks after (n = 11) starting treatment with abiraterone. Tumour to normal bone (T:N) ratios, tumour to muscle (T:M) ratios and CT Hounsfield units (HU) were measured in up to five target metastases in each subject. An oncologist blinded to study scans assessed clinical responses up to 24 weeks using conventional criteria.

Results

Before treatment, metastases showed specific 99mTc-maraciclatide accumulation (mean planar T:N and T:M ratios 1.43 and 3.06; SPECT T:N and T:M ratios 3.1 and 5.19, respectively). Baseline sclerotic lesions (389–740 HU) showed lower T:M ratios (4.22 vs. 7.04, p = 0.02) than less sclerotic/lytic lesions (46–381 HU). Patients with progressive disease (PD; n = 5) showed increased planar T:N and T:M ratios (0.29 and 12.1%, respectively) and SPECT T:N and T:M ratios (11.9 and 20.2%, respectively). Patients without progression showed decreased planar T:N and T:M ratios (0.27 and −8.0%, p = 1.0 and 0.044, respectively) and SPECT T:N and T:M ratios (−21.9, and −27.2%, p = 0.3 and 0.036, respectively). The percentage change in CT HU was inversely correlated with the percentage change in SPECT T:M ratios (r = −0.59, p = 0.006).

Conclusions

99mTc-maraciclatide accumulates in PCa bone metastases in keeping with increased αvβ3 integrin expression. Greater activity in metastases with lower CT density suggests that uptake is related to osteoclast activity. Changes in planar and SPECT T:M ratios after 12 weeks of treatment differed between patients with and without PD and 99mTc-maraciclatide imaging may be a potential method for assessing early response.



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Prospective observational study of 177 Lu-DOTA-octreotate therapy in 200 patients with advanced metastasized neuroendocrine tumours (NETs): feasibility and impact of a dosimetry-guided study protocol on outcome and toxicity

Abstract

Purpose

Peptide receptor radionuclide therapy in patients with neuroendocrine tumours has yielded promising results. This prospective study investigated the feasibility of dosimetry of the kidneys and bone marrow during therapy and its impact on efficacy and outcome.

Methods

The study group comprised 200 consecutive patients with metastasized somatostatin receptor-positive neuroendocrine tumours progressing on standard therapy or not suitable for other therapeutic options. A treatment cycle consisted of 7.4 GBq 177Lu-DOTA-octreotate with co-infusion of a mixed amino acid solution, and cycles were repeated until the absorbed dose to the kidneys reached 23 Gy or there were other reasons for stopping therapy. The Ki-67 index was ≤2% in 47 patients (23.5%), 3–20% in 121 (60.5%) and >20% in 16 (8%).

Results

In 123 patients (61.5%) the absorbed dose to the kidneys reached 23 Gy with three to nine cycles during first-line therapy; in no patient was a dose to the bone marrow of 2 Gy reached. The best responses (according to RECIST 1.1) were a complete response (CR) in 1 patient (0.5%), a partial response (PR) in 47 (23.5%), stable disease (SD) in 135 (67.5%) and progressive disease (PD) in 7 (3.5%). Median progression-free survival was 27 months (95% CI 22–30 months) in all patients, 33 months in those in whom the absorbed dose to the kidneys reached 23 Gy and 15 months in those in whom it did not. Median overall survival (OS) was 43 months (95% CI 39–53 months) in all patients, 54 months in those in whom the absorbed dose to the kidneys reached 23 Gy and 25 months in those in whom it did not. Median OS was 60 months in patients with a best response of PR or CR, 42 months in those with SD and 16 months in those with PD. Three patients (1.5%) developed acute leukaemia, 1 patient (0.5%) chronic leukaemia (unconfirmed) and 30 patients (15%) grade 3 or 4 bone marrow toxicity. Eight patients (4%) developed grade 2 kidney toxicity and one patient (0.5%) grade 4 kidney toxicity.

Conclusions

Dosimetry-based therapy with 177Lu-DOTA-octreotate is feasible. Patients in whom the absorbed dose to the kidneys reached 23 Gy had a longer OS than those in whom it did not. Patients with CR/PR had a longer OS than those with SD. Bone marrow dosimetry did not predict toxicity.



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Cancer metastasizes to the bone marrow and not to the bone: time for a paradigm shift!



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Antitumor effects of radionuclide treatment using α-emitting meta - 211 At-astato-benzylguanidine in a PC12 pheochromocytoma model

Abstract

Purpose

Therapeutic options for patients with malignant pheochromocytoma are currently limited, and therefore new treatment approaches are being sought. Targeted radionuclide therapy provides tumor-specific systemic treatments. The β-emitting radiopharmaceutical meta-131I-iodo-benzylguanidine (131I-MIBG) provides limited survival benefits and has adverse effects. A new generation of radionuclides for therapy using α-particles including meta-211At-astato-benzylguanidine (211At-MABG) are expected to have strong therapeutic effects with minimal side effects. However, this possibility has not been evaluated in an animal model of pheochromocytoma. We aimed to evaluate the therapeutic effects of the α-emitter 211At-MABG in a pheochromocytoma model.

Methods

We evaluated tumor volume-reducing effects of 211At-MABG using rat pheochromocytoma cell line PC12 tumor-bearing mice. PC12 tumor-bearing mice received intravenous injections of 211At-MABG (0.28, 0.56, 1.11, 1.85, 3.70 and 5.55 MBq; five mice per group). Tumor volumes were evaluated for 8 weeks after 211At-MABG administration. The control group of ten mice received phosphate-buffered saline.

Results

The 211At-MABG-treated mice showed significantly lower relative tumor growth during the first 38 days than the control mice. The relative tumor volumes on day 21 were 509.2% ± 169.1% in the control mice and 9.6% ± 5.5% in the mice receiving 0.56 MBq (p < 0.01). In addition, the mice treated with 0.28, 0.56 and 1.11 MBq of 211At-MABG showed only a temporary weight reduction, with recovery in weight by day 10.

Conclusion

211At-MABG exhibited a strong tumor volume-reducing effect in a mouse model of pheochromocytoma without weight reduction. Therefore, 211At-MABG might be an effective therapeutic agent for the treatment of malignant pheochromocytoma.



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The relationship between local recurrences and distant metastases in prostate cancer: can 11 C-choline PET/CT contribute to understand the link?

Abstract

Purpose

Previous studies in prostate cancer (PCa) patients tried to correlate the onset of local recurrence (LR) with the development of distant metastases and formulated, based on theoretical and experimental data, hypotheses linking the two events. We aimed to address this issue with 11C-choline positron emission tomography/computed tomography (PET/CT).

Methods

This retrospective study included 491 PCa patients previously treated with radical prostatectomy who had undergone 11C-choline PET/CT owing to biochemical failure. Further inclusion criteria were availability of clinical and pathological variables for survival analysis. Statistical significance was taken at P < 0.05.

Results

Seventy-two patients (14.7%) had evidence of LR at 11C-choline PET/CT. The frequency of LR increased from 13.8% in the interval 0–4 years after prostatectomy, to 23.9% in the 12–16-year interval (P = 0.080). On the contrary, the frequency of lymph node metastases (overall rate in the 0–16 years interval after prostatectomy: 26.3%) and of bone metastases (overall rate: 13.8%) decreased significantly over time. Kaplan-Meier curves showed no significant group difference in the rates of lymph node or bone metastases between patients with LR and patients without LR. LR significantly predicted PCa-specific survival at univariate analysis, but the statistical significance was lost at multivariate analysis.

Conclusion

We found no differences in the rates of lymph node and bone metastases between patients with and without LR. An inverse time-dependent trend was observed in the frequency of LR on one side and of lymph node and bone metastases on the other side. These findings were discussed in relation to previous theories linking LR to distant metastases and our study design.



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FDG-PET/CT for treatment response assessment in head and neck squamous cell carcinoma: a systematic review and meta-analysis of diagnostic performance

Abstract

Purpose

18-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) is increasingly used to evaluate treatment response in head and neck squamous cell carcinoma (HNSCC). This analysis assessed the diagnostic value of FDG-PET/CT in detecting nodal disease within 6 months after treatment, considering patient and disease characteristics.

Methods

A systematic review was performed using the MEDLINE and Web of Knowledge databases. The results were pooled using a bivariate random effects model of the sensitivity and specificity.

Results

Out of 22 identified studies, a meta-analysis of 20 studies (1293 patients) was performed. The pooled estimates of sensitivity, specificity and diagnostic odds ratio (with 95% CI) were 85% (76–91%), 93% (89–96%) and 76 (35–165), respectively. With the prevalence set at 10%, the positive and negative predictive values were 58% and 98%. There was significant heterogeneity between the trials (p < 0.001). HPV positive tumors were associated with lower sensitivity (75% vs 89%; p = 0.01) and specificity (87% vs 95%; p < 0.005).

Conclusion

FDG-PET/CT within 6 months after (chemo)radiotherapy in HNSCC patients is a reliable method for ruling out residual/recurrent nodal disease and obviates the need for therapeutic intervention. However, FDG-PET/CT may be less reliable in HPV positive tumors and the optimal surveillance strategy remains to be determined.



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