Σάββατο, 31 Μαρτίου 2018

Effect of varying computed tomography acquisition and reconstruction parameters on semi-automated clot volume quantification.

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Effect of varying computed tomography acquisition and reconstruction parameters on semi-automated clot volume quantification.

World J Radiol. 2018 Mar 28;10(3):24-29

Authors: Kaufman AE, Pruzan AN, Hsu C, Ramachandran S, Jacobi A, Fayad ZA, Mani V

Abstract
AIM: To examine effects of computed tomography (CT) image acquisition/reconstruction parameters on clot volume quantification in vitro for research method validation purposes.
METHODS: This study was performed in conformance with HIPAA and IRB Regulations (March 2015-November 2016). A ten blood clot phantom was designed and scanned on a dual-energy CT scanner (SOMATOM Force, Siemens Healthcare GmBH, Erlangen, Germany) with varying pitch, iterative reconstruction, energy level and slice thickness. A range of clot and tube sizes were used in an attempt to replicate in vivo emboli found within central and segmental branches of the pulmonary arteries in patients with pulmonary emboli. Clot volume was the measured parameter and was analyzed by a single image analyst using a semi-automated region growing algorithm implemented in the FDA-approved Siemens syngo.via image analysis platform. Mixed model analysis was performed on the data.
RESULTS: On the acquisition side, the continuous factor of energy showed no statistically significant effect on absolute clot volume quantification (P = 0.9898). On the other hand, when considering the fixed factor of pitch, there were statistically significant differences in clot volume quantification (P < 0.0001). On the reconstruction side, with the continuous factor of reconstruction slice thickness no statistically significant effect on absolute clot volume quantification was demonstrated (P = 0.4500). Also on the reconstruction side, with the fixed factor of using iterative reconstructions there was also no statistically significant effect on absolute clot volume quantification (P = 0.3011). In addition, there was excellent R2 correlation between the scale-measured mass of the clots both with respect to the CT measured volumes and with respect to volumes measure by the water displacement method.
CONCLUSION: Aside from varying pitch, changing CT acquisition parameters and using iterative reconstructions had no significant impact on clot volume quantification with a semi-automated region growing algorithm.

PMID: 29599936 [PubMed]



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Submandibular Gland Transfer: A Potential Imaging Pitfall.

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Submandibular Gland Transfer: A Potential Imaging Pitfall.

AJNR Am J Neuroradiol. 2018 Mar 29;:

Authors: Wu X, Yom SS, Ha PK, Heaton CM, Glastonbury CM

Abstract
BACKGROUND AND PURPOSE: The Seikaly and Jha submandibular gland transfer surgery is performed to facilitate gland shielding during radiation therapy for head and neck tumors to circumvent radiation-induced xerostomia. It results in an asymmetric postsurgical appearance of the submandibular and submental spaces. Our purpose was to characterize the morphologic and enhancement characteristics of the transferred submandibular gland and identify potential pitfalls in postoperative radiologic interpretation.
MATERIALS AND METHODS: This retrospective study identified patients with head and neck cancer who had undergone the submandibular gland transfer procedure at our institution. Chart reviews were performed to identify relevant oncologic histories and therapies. CT and MR neck imaging was reviewed to characterize morphologic and enhancement characteristics of the pre- and postoperative submandibular glands, as well as interpretive accuracy.
RESULTS: Eleven patients with oropharyngeal and nasopharyngeal squamous cell carcinomas who underwent submandibular gland transfer were identified. The transferred glands were significantly lengthened in the anteroposterior dimension compared with contralateral glands (P < .001) and displaced anteriorly and inferiorly within the submandibular and submental spaces. Enhancement patterns of the transferred submandibular glands varied, depending on the time of imaging relative to the operation and radiation therapy. Submandibular gland transfer was acknowledged in the postoperative report in 7/11 cases. Errors in interpretation were present in 2/11 reports.
CONCLUSIONS: After the submandibular gland transfer procedure, the submandibular and submental spaces lose their symmetric appearances as the transferred submandibular glands become lengthened and located more anteriorly and inferiorly, with variable enhancement characteristics. Familiarity with the postsurgical appearance of the transferred submandibular glands is key to accurate imaging interpretation.

PMID: 29599172 [PubMed - as supplied by publisher]



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An Update on the Adjunctive Neurovascular Support of Wide-Neck Aneurysm Embolization and Reconstruction Trial: 1-Year Safety and Angiographic Results.

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An Update on the Adjunctive Neurovascular Support of Wide-Neck Aneurysm Embolization and Reconstruction Trial: 1-Year Safety and Angiographic Results.

AJNR Am J Neuroradiol. 2018 Mar 29;:

Authors: Spiotta AM, Chaudry MI, Turner RD, Turk AS, Derdeyn CP, Mocco J, Tateshima S

Abstract
BACKGROUND AND PURPOSE: The safety and efficacy of the PulseRider for the treatment of wide-neck, bifurcation aneurysms at the basilar and carotid terminus locations were studied in a prospective trial, the Adjunctive Neurovascular Support of Wide-Neck Aneurysm Embolization and Reconstruction (ANSWER) trial, reporting on initial 6-month angiographic and clinical results. This report provides insight into the longer term durability and safety with 12-month data.
MATERIALS AND METHODS: Aneurysms treated with the PulseRider among enrolled sites were prospectively studied. Updated 12-month data on clinical and imaging end points are included.
RESULTS: Thirty-four patients were enrolled (29 women, 5 men) with a mean age of 60.9 years. The mean aneurysm height ranged from 2.4 to 15.9 mm with a mean neck size of 5.2 mm (range, 2.3-11.6 mm). At 1 year, there were no device migrations or symptomatic in-stent stenoses. Raymond-Roy I occlusion was achieved in 53% of cases at the time of treatment and progressed to 61% and 67% at 6 and 12 months, respectively. Adequate occlusion (Raymond-Roy I/II) progressed from 88% at 6 months to 90% at 12 months. No recanalizations were observed. There was 1 delayed ischemic event. Good outcome (mRS 0-2) was achieved in 90% of patients.
CONCLUSIONS: The updated 1-year results from the ANSWER trial demonstrate aneurysm stability and an acceptable safety profile for aneurysms treated at the basilar apex and carotid terminus. Prospective data from a larger set of aneurysms treated at other locations are required to assess how treatment with PulseRider compares with alternatives for treating wide-neck bifurcation aneurysms.

PMID: 29599174 [PubMed - as supplied by publisher]



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Parent Artery Reconstruction for Large or Giant Cerebral Aneurysms Using the Tubridge Flow Diverter: A Multicenter, Randomized, Controlled Clinical Trial (PARAT).

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Parent Artery Reconstruction for Large or Giant Cerebral Aneurysms Using the Tubridge Flow Diverter: A Multicenter, Randomized, Controlled Clinical Trial (PARAT).

AJNR Am J Neuroradiol. 2018 Mar 29;:

Authors: Liu JM, Zhou Y, Li Y, Li T, Leng B, Zhang P, Liang G, Huang Q, Yang PF, Shi H, Zhang J, Wan J, He W, Liang C, Zhu G, Xu Y, Hong B, Yang X, Bai W, Tian Y, Zhang H, Li Z, Li Q, Zhao R, Fang Y, Zhao K, PARAT investigators

Abstract
BACKGROUND AND PURPOSE: Although flow diverters have been reported with favorable clinical and angiographic outcomes in various literatures, randomized trials determining their true effectiveness and safety are still in lack. The Parent Artery Reconstruction for Large or Giant Cerebral Aneurysms Using the Tubridge Flow Diverter (PARAT) trial was designed to evaluate the safety and efficacy of the Tubridge flow diverter in the treatment of large or giant aneurysms in comparison with Enterprise stent-assisted coiling.
MATERIALS AND METHODS: This prospective, multicenter, randomized trial was conducted at 12 hospitals throughout China. Enrolled adults with unruptured large/giant intracranial aneurysms were randomly assigned (1:1) to receive either Enterprise stent-assisted coiling or Tubridge flow diverter implantation. The primary end point was complete occlusion at 6-month follow-up, while secondary end points included technical success, mortality, target vessel-related stroke, aneurysm bleeding, in-stent stenosis, parent artery occlusion, and the frequency of all adverse events.
RESULTS: Among 185 enrolled subjects, 41 withdrew before procedure initiation. Overall, 82 subjects underwent Tubridge implantation, and 62 subjects were primarily treated with stent-assisted coiling. The results of 6-month follow-up imaging included complete occlusion rates of 75.34% versus 24.53% for the Tubridge and stent-assisted coiling groups, respectively, with a calculated common odds ratio of 9.4 (95% confidence interval, 4.14-21.38; P < .001). There was a higher, nonsignificant frequency of complications for Tubridge subjects. Multivariate analysis showed a decreased stroke rate at the primary investigational site, with a marginal P value (P = .051).
CONCLUSIONS: This trial showed an obviously higher rate of large and giant aneurysm obliteration with the Tubridge FD over Enterprise stent-assisted coiling. However, this higher obliteration rate came at the cost of a nonsignificantly higher rate of complications. Investigational site comparisons suggested that a learning curve for flow-diverter implantation should be recognized and factored into trial designs.

PMID: 29599173 [PubMed - as supplied by publisher]



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Signal Change of Acute Cortical and Juxtacortical Microinfarction on Follow-Up MRI.

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Signal Change of Acute Cortical and Juxtacortical Microinfarction on Follow-Up MRI.

AJNR Am J Neuroradiol. 2018 Mar 29;:

Authors: Miyata M, Kakeda S, Yoneda T, Ide S, Watanabe K, Moriya J, Korogi Y

Abstract
BACKGROUND AND PURPOSE: Although the clinical importance of cortical microinfarcts has become well-recognized recently, the evolution of cortical microinfarcts on MR imaging is not fully understood. The aim of this study was to examine the temporal changes in acute cortical microinfarcts using susceptibility-weighted imaging and conventional MR imaging.
MATERIALS AND METHODS: Patients with acute infarcts located in the cortical and/or juxtacortical region measuring ≤10 mm in axial diameter based on diffusion-weighted imaging who had a follow-up 3T MR imaging were retrospectively included in the study. All lesions did not show hypointensity on initial T2*WI. For cortical and/or juxtacortical microinfarcts detected on initial DWI, 2 neuroradiologists evaluated the follow-up MR imaging (T2WI, FLAIR, T2*WI, and SWI) and assessed lesion signal intensities and locations (cortical microinfarcts or microinfarcts with juxtacortical white matter involvement).
RESULTS: On initial DWI, 2 radiologists observed 180 cortical and/or juxtacortical microinfarcts in 35 MR imaging examinations in 25 patients; on follow-up, the neuroradiologists identified 29 cortical microinfarcts (16%) on T2WI, 9 (5%) on FLAIR, 4 (2%) on T2*, and 97 (54%) on SWI. All cortical microinfarcts detected with any follow-up MR imaging showed hyperintensity on T2WI/FLAIR and/or hypointensity on T2*WI and SWI.
CONCLUSIONS: SWI revealed conversion (paramagnetic susceptibility changes) of acute cortical microinfarcts, suggesting that a substantial number of cortical microinfarcts may contain hemorrhagic components.

PMID: 29599171 [PubMed - as supplied by publisher]



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Blood Flow Mimicking Aneurysmal Wall Enhancement: A Diagnostic Pitfall of Vessel Wall MRI Using the Postcontrast 3D Turbo Spin-Echo MR Imaging Sequence.

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Blood Flow Mimicking Aneurysmal Wall Enhancement: A Diagnostic Pitfall of Vessel Wall MRI Using the Postcontrast 3D Turbo Spin-Echo MR Imaging Sequence.

AJNR Am J Neuroradiol. 2018 Mar 29;:

Authors: Kalsoum E, Chabernaud Negrier A, Tuilier T, Benaïssa A, Blanc R, Gallas S, Lefaucheur JP, Gaston A, Lopes R, Brugières P, Hodel J

Abstract
Our aim was to compare the detectability of aneurysmal wall enhancement in unruptured intracranial aneurysms between conventional and motion-sensitized driven equilibrium-prepared postcontrast 3D T1-weighted TSE sequences (sampling perfection with applicationoptimized contrasts by using different flip angle evolution, SPACE). Twenty-two patients with 30 unruptured intracranial aneurysms were scanned at 3T. Aneurysmal wall enhancement was more significantly detected using conventional compared with motion-sensitized driven equilibrium-prepared SPACE sequences (10/30 versus 2/30, P < .0001). Contrast-to-noise ratio measurements did not differ between conventional and motion-sensitized driven equilibrium-prepared sequences (P = .51). Flowing blood can mimic aneurysmal wall enhancement using conventional SPACE sequences with potential implications for patient care.

PMID: 29599170 [PubMed - as supplied by publisher]



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Aneurysmal Parent Artery-Specific Inflow Conditions for Complete and Incomplete Circle of Willis Configurations.

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Aneurysmal Parent Artery-Specific Inflow Conditions for Complete and Incomplete Circle of Willis Configurations.

AJNR Am J Neuroradiol. 2018 Mar 29;:

Authors: Cornelissen BMW, Schneiders JJ, Sprengers ME, van den Berg R, van Ooij P, Nederveen AJ, van Bavel E, Vandertop WP, Slump CH, Marquering HA, Majoie CBLM

Abstract
BACKGROUND AND PURPOSE: Hemodynamics are thought to play a role in intracranial aneurysm growth and rupture. Computational fluid dynamics is frequently performed to assess intra-aneurysmal hemodynamics, using generalized flow waveforms of healthy volunteers as inflow boundary conditions. The purpose of this study was to assess differences in inflow conditions for different aneurysmal parent artery locations and variations of circle of Willis configurations.
MATERIALS AND METHODS: In a series of 96 patients with 103 aneurysms, velocity measurements were acquired using 2D phase-contrast MR imaging perpendicular to the aneurysmal parent arteries in the circle of Willis. Circle of Willis configurations were inspected for variations using multiple overlapping thin-slab-acquisition MRAs. Flow rates, velocity magnitudes, and pulsatility indices were calculated for each parent artery location in subgroups of complete and incomplete circle of Willis configurations.
RESULTS: Flow rates, velocity magnitudes, and pulsatility indices were significantly different among aneurysmal parent arteries. Incomplete circle of Willis configurations were observed in 24% of the cases. Significantly lower basilar artery flow rates were observed in configurations with hypoplastic P1 segments. Significantly higher A1 flow rates were observed in configurations with a hypoplastic contralateral A1 segment.
CONCLUSIONS: Inflow conditions vary substantially between aneurysmal parent arteries and circle of Willis configurations. We have created a collection of parent artery-specific inflow conditions tailored to the patient-specific circle of Willis configuration that can be used in future computational fluid dynamics studies analyzing intra-aneurysmal hemodynamics.

PMID: 29599169 [PubMed - as supplied by publisher]



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Appropriateness of tricyclic antidepressants in the geriatric population: A critical interpretation of existing literature.

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Appropriateness of tricyclic antidepressants in the geriatric population: A critical interpretation of existing literature.

Oral Surg Oral Med Oral Pathol Oral Radiol. 2018 Mar 09;:

Authors: Farag AM, Desai B

PMID: 29599082 [PubMed - as supplied by publisher]



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Differentiation Between Brucellar and Tuberculous Spondylodiscitis in the Acute and Subacute Stages by MRI

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Publication date: Available online 30 March 2018
Source:Academic Radiology
Author(s): Xinxin Liu, Hua Li, Chao Jin, Gang Niu, Baoqin Guo, Yi Chen, Jian Yang
Rationale and ObjectivesThe aim of this study was to reveal the distinctive features of magnetic resonance imaging (MRI) for distinguishing brucellar spondylodiscitis (BSD) from tuberculous spondylodiscitis (TSD) in the acute and subacute stages.MethodsThis study involved 14 patients with BSD and 18 patients with TSD from May 2011 to January 2015. BSD was diagnosed based on ≥1/160 titers of a Brucella agglutination test or isolation of Brucella spp. TSD was diagnosed based on the isolation of tuberculosis bacteria. All patients underwent T1- and T2-weight imaging (T1WI and T2WI) and fat suppression T2WI (FS T2WI). The height and the signal intensity (SI) of the vertebra and intervertebral disc were assessed. The distinctive MRI features were compared using the chi-square test. The SI of the vertebra between BSD and TSD was observed in terms of histogram characteristics of kurtosis, skewness, and percentile (75%–25%) on FS T2WI.ResultsTwenty-nine (76.3%) vertebrae of BSD were infected throughout the whole vertebra, and 49 (90.7%) vertebrae of TSD were infected near the osseous end plate (P < .001). Compared to TSD, the vertebral height of BSD was nearly intact (P < .001), owing to the new bone formation in the end plate without vertebral collapse. Furthermore, significant differences in the SI of the vertebra were observed between patients with BSD and TSD in terms of homogeneous characteristics on FS T2WI, that is, kurtosis (BSD vs TSD, 0.107 vs −0.250, P = .023), skewness (BSD vs TSD, −0.021 vs 0.266, P = .017), and percentile (75%–25%) (BSD vs TSD, 54.498 vs 79.399, P = .00049).ConclusionsThe nearly intact vertebra with homogeneous high signal on FS T2WI was an important MRI feature for distinguishing BSD from TSD in the acute and subacute stages.



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Rethinking the PGY-1 Basic Clinical Year

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Publication date: Available online 30 March 2018
Source:Academic Radiology
Author(s): Kathryn E. Darras, Abigail A. Arnold, Colin Mar, Bruce B. Forster, Linda Probyn, Silvia D. Chang
Rationale and ObjectivesRecently, the relevance of the postgraduate year 1 (PGY-1) Basic Clinical Year for radiology residents has been questioned. The purpose of this study was to determine the attitude of radiologists and trainees toward this year and which clinical rotations they perceived as most valuable to clinical practice.Materials and MethodsFollowing institutional review board approval, an anonymous online survey was administered to Canadian radiologists and radiology trainees. In addition to reporting demographic information, respondents were asked to rank the usefulness of individual rotations on a five-point Likert scale. To assess whether there are differences in the ratings and therefore rankings of the rotations by gender, position, and level of training, the Kruskal-Wallis one-way analysis of variance test was used with significance defined as P < .05. The Schulze method was used to rank the perceived usefulness of clinical rotations considered.ResultsOf the 275 respondents, 73.1% were male and 47.3% were trainees. A total of 71.3% of respondents were in favor of the basic clinical year, whereas 16.4% opposed. There was a statistically significant difference between the responses of staff radiologists and trainees, with the staff more strongly favoring the Basic Clinical Year (84.1%) than the trainees (56.9%) (P < .0001). As a whole, the respondents favored general surgery rotations as most relevant to their clinical practice (agreement rate of 48.3%). Interventional radiologists found general and subspecialty surgical rotations to be equally relevant. The rotations deemed to be "essential" were emergency medicine (48.7%) and general surgery (46.6%), and the rotations deemed to be "very useful" were orthopedics (45.8%), trauma (44.4%), neurosurgery (43.3%), neurology (42.2%), and hepatobiliary surgery (38.9%). There was no statistical difference between the respondents' choices based on their level of experience and scope of practice.ConclusionsMost radiologists and radiology trainees were in favor of completing the PGY-1 Basic Clinical Year. However, programs should maximize the education value of this year by including more of the top-ranked rotations. As the practice of radiology evolves, it is important to ensure that training paradigms continue to prepare residents for independent practice.



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Determination of Prostate Volume

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Publication date: Available online 30 March 2018
Source:Academic Radiology
Author(s): Adam Bezinque, Andrew Moriarity, Crystal Farrell, Henry Peabody, Sabrina L. Noyes, Brian R. Lane
Rationale and ObjectivesProstate volume (PV) determination provides important clinical information. We compared PVs determined by digital rectal examination (DRE), transrectal ultrasound (TRUS), magnetic resonance imaging (MRI) with or without three-dimensional (3D) segmentation software, and surgical prostatectomy weight (SPW) and volume (SPV).Materials and MethodsThis retrospective review from 2010 to 2016 included patients who underwent radical prostatectomy ≤1 year after multiparametric prostate MRI. PVs from DRE and TRUS were obtained from urology clinic notes. MRI-based PVs were calculated using bullet and ellipsoid formulas, automated 3D segmentation software (MRI-A3D), manual segmentation by a radiologist (MRI-R3D), and a third-year medical student (MRI-S3D). SPW and SPV were derived from pathology reports. Intraclass correlation coefficients compared the relative accuracy of each volume measurement.ResultsNinety-nine patients were analyzed. Median PVs were DRE 35 mL, TRUS 35 mL, MRI-bullet 49 mL, MRI-ellipsoid 39 mL, MRI-A3D 37 mL, MRI-R3D 36 mL, MRI-S3D 36 mL, SPW 54 mL, SPV-bullet 47 mL, and SPV-ellipsoid 37 mL. SPW and bullet formulas had consistently large PV, and formula-based PV had a wider spread than PV based on segmentation. Compared to MRI-R3D, the intraclass correlation coefficient was 0.91 for MRI-S3D, 0.90 for MRI-ellipsoid, 0.73 for SPV-ellipsoid, 0.72 for MRI-bullet, 0.71 for TRUS, 0.70 for SPW, 0.66 for SPV-bullet, 0.38 for MRI-A3D, and 0.33 for DRE.ConclusionsWith MRI-R3D measurement as the reference, the most reliable methods for PV estimation were MRI-S3D and MRI-ellipsoid formula. Automated segmentations must be individually assessed for accuracy, as they are not always truly representative of the prostate anatomy. Manual segmentation of the prostate does not require expert training.



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Deep Learning in Radiology

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Publication date: Available online 30 March 2018
Source:Academic Radiology
Author(s): Morgan P. McBee, Omer A. Awan, Andrew T. Colucci, Comeron W. Ghobadi, Nadja Kadom, Akash P. Kansagra, Srini Tridandapani, William F. Auffermann
As radiology is inherently a data-driven specialty, it is especially conducive to utilizing data processing techniques. One such technique, deep learning (DL), has become a remarkably powerful tool for image processing in recent years. In this work, the Association of University Radiologists Radiology Research Alliance Task Force on Deep Learning provides an overview of DL for the radiologist. This article aims to present an overview of DL in a manner that is understandable to radiologists; to examine past, present, and future applications; as well as to evaluate how radiologists may benefit from this remarkable new tool. We describe several areas within radiology in which DL techniques are having the most significant impact: lesion or disease detection, classification, quantification, and segmentation. The legal and ethical hurdles to implementation are also discussed. By taking advantage of this powerful tool, radiologists can become increasingly more accurate in their interpretations with fewer errors and spend more time to focus on patient care.



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Παρασκευή, 30 Μαρτίου 2018

Three-dimensional cluster formation and structure in heterogeneous dose distribution of intensity modulated radiation therapy

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Publication date: Available online 30 March 2018
Source:Radiotherapy and Oncology
Author(s): Ming Chao, Jie Wei, Ganesh Narayanasamy, Yading Yuan, Yeh-Chi Lo, José A. Peñagarícano
PurposeTo investigate three-dimensional cluster structure and its correlation to clinical endpoint in heterogeneous dose distributions from intensity modulated radiation therapy.MethodsTwenty-five clinical plans from twenty-one head and neck (HN) patients were used for a phenomenological study of the cluster structure formed from the dose distributions of organs at risks (OARs) close to the planning target volumes (PTVs). Initially, OAR clusters were searched to examine the pattern consistence among ten HN patients and five clinically similar plans from another HN patient. Second, clusters of the esophagus from another ten HN patients were scrutinized to correlate their sizes to radiobiological parameters. Finally, an extensive Monte Carlo (MC) procedure was implemented to gain deeper insights into the behavioral properties of the cluster formation.ResultsClinical studies showed that OAR clusters had drastic differences despite similar PTV coverage among different patients, and the radiobiological parameters failed to positively correlate with the cluster sizes. MC study demonstrated the inverse relationship between the cluster size and the cluster connectivity, and the nonlinear changes in cluster size with dose thresholds. In addition, the clusters were insensitive to the shape of OARs.ConclusionThe results demonstrated that the cluster size could serve as an insightful index of normal tissue damage. The clinical outcome of the same dose–volume might be potentially different.



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Correction to: Dynamic susceptibility contrast (DSC) perfusion MRI in differential diagnosis between radionecrosis and neoangiogenesis in cerebral metastases using rCBV, rCBF and K2

Abstract

In the original publication of the article, the name of the last author was incorrect. The correct name should read as given below:



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Three-dimensional cluster formation and structure in heterogeneous dose distribution of intensity modulated radiation therapy

To investigate three-dimensional cluster structure and its correlation to clinical endpoint in heterogeneous dose distributions from intensity modulated radiation therapy.

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Fast 5DOF needle tracking in iOCT

Abstract

Purpose

Intraoperative optical coherence tomography (iOCT) is an increasingly available imaging technique for ophthalmic microsurgery that provides high-resolution cross-sectional information of the surgical scene. We propose to build on its desirable qualities and present a method for tracking the orientation and location of a surgical needle. Thereby, we enable the direct analysis of instrument–tissue interaction directly in OCT space without complex multimodal calibration that would be required with traditional instrument tracking methods.

Method

The intersection of the needle with the iOCT scan is detected by a peculiar multistep ellipse fitting that takes advantage of the directionality of the modality. The geometric modeling allows us to use the ellipse parameters and provide them into a latency-aware estimator to infer the 5DOF pose during needle movement.

Results

Experiments on phantom data and ex vivo porcine eyes indicate that the algorithm retains angular precision especially during lateral needle movement and provides a more robust and consistent estimation than baseline methods.

Conclusion

Using solely cross-sectional iOCT information, we are able to successfully and robustly estimate a 5DOF pose of the instrument in less than 5.4 ms on a CPU.



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A rare case of atypical thoracodorsal artery: a challenge for flap reconstruction.

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A rare case of atypical thoracodorsal artery: a challenge for flap reconstruction.

Surg Radiol Anat. 2018 Mar 29;:

Authors: Kumar N, Aithal AP, Nayak SB, Bhaskar R

Abstract
The thoracodorsal artery mainly supplies the latissimus dorsi muscle. Anatomical details pertaining to the origin and distribution of thoracodorsal artery are important because the latissimus dorsi myocutaneous flap is one of the most reliable and versatile flaps used in reconstructive surgery. Atypical origin and course of the thoracodorsal artery is, therefore, a challenge for flap reconstruction surgeries. In the present case, we report multiple variations in the branching pattern of axillary artery. The thoracodorsal artery had an unusual origin from the second part of axillary artery. The trunk of thoracoacromial artery was absent. The thoracodorsal artery after its origin, descended downwards over the lateral pectoral region lying deep to pectoralis minor but superficial to teres major muscles. It terminated by supplying the latissimus dorsi muscle. Due to the presence of atypical thoracodorsal branch, the subscapular artery continued as the circumflex scapular artery.

PMID: 29594336 [PubMed - as supplied by publisher]



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The retromolar canals and foramina: radiographic observation and application to oral surgery.

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The retromolar canals and foramina: radiographic observation and application to oral surgery.

Surg Radiol Anat. 2018 Mar 29;:

Authors: Kikuta S, Iwanaga J, Nakamura K, Hino K, Nakamura M, Kusukawa J

Abstract
PURPOSE: The retromolar canal (RMC) and foramen (RMF) are anatomic variants in the retromolar area of the mandible. The purpose of this study was to clarify the relationship between the RMC and RMF and related complications, and to reveal how the RMC could impact the mandibular anatomy using cone-beam computed tomography (CBCT) and panoramic images (PAN).
MATERIALS AND METHODS: CBCT and PAN images of 50 patients were retrospectively analyzed to investigate the morphology of the RMC and RMF, and their impact on impacted third molar surgery and orthognathic surgery.
RESULTS: In PAN images, neither the RMC nor RMF was detected. In CBCT images, the RMCs were detected in 26% (13/50) of the patients. A double RMC was detected on one side of one patient. The diameter of the RMC ranged from 0.8 to 2.9 mm (mean; 1.5 ± 0.6 mm), and the RMF ranged from 0.6 to 2.3 mm (mean; 1.1 ± 0.5 mm). No patients experienced unexpected bleeding. Unilateral postoperative hypoesthesia of the buccal gingiva in the molar region was reported in 6.7% of patients with the RMC.
CONCLUSIONS: Hypoesthesia of the buccal gingiva in the lower molar region may be the main complication when the RMC is damaged.

PMID: 29594335 [PubMed - as supplied by publisher]



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Uncertainty in positioning ion chamber at reference depth for various water phantoms

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Publication date: May–June 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 3
Author(s): Naoki Kinoshita, Hiroshi Oguchi, Toshiki Adachi, Hiroki Shioura, Hirohiko Kimura
BackgroundUncertainty in the calibration of high-energy radiation sources is dependent on user and equipment type.AimWe evaluated the uncertainty in the positioning of a cylindrical chamber at a reference depth for reference dosimetry of high-energy photon beams and the resulting uncertainty in the chamber readings for 6- and 10-MV photon beams. The aim was to investigate major contributions to the positioning uncertainty to reduce the uncertainty in calibration for external photon beam radiotherapy.Materials and methodsThe following phantoms were used: DoseView 1D, WP1D, 1D SCANNER, and QWP-07 as one-dimensional (1D) phantoms for a vertical-beam geometry; GRI-7632 as a phantom for a fixed waterproofing sleeve; and PTW type 41023 and QWP-04 as 1D phantoms for a horizontal-beam geometry. The uncertainties were analyzed as per the Guide to the Expression of Uncertainty in Measurement.ResultsThe positioning and resultant uncertainties in chamber readings ranged from 0.22 to 0.35mm and 0.12–0.25%, respectively, among the phantoms (using a coverage factor k=1 in both cases). The major contributions to positioning uncertainty are: definition of the origin for phantoms among users for the 1D phantoms for a vertical-beam geometry, water level adjustment among users for the phantom for a fixed waterproofing sleeve, phantom window deformation, and non-water material of the window for the 1D phantoms for a horizontal-beam geometry.ConclusionThe positioning and resultant uncertainties in chamber readings exhibited minor differences among the seven phantoms. The major components of these uncertainties differed among the phantom types investigated.



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Dual addressing of thymidine synthesis pathways for effective targeting of proliferating melanoma.

http:--media.wiley.com-assets-7315-18-Wi https:--www.ncbi.nlm.nih.gov-corehtml-pm Related Articles

Dual addressing of thymidine synthesis pathways for effective targeting of proliferating melanoma.

Cancer Med. 2017 Jul;6(7):1639-1651

Authors: Miran T, Vogg ATJ, El Moussaoui L, Kaiser HJ, Drude N, von Felbert V, Mottaghy FM, Morgenroth A

Abstract
Here, we examined the potential of blocking the thymidine de novo synthesis pathways for sensitizing melanoma cells to the nucleoside salvage pathway targeting endogenous DNA irradiation. Expression of key nucleotide synthesis and proliferation enzymes thymidylate synthase (TS) and thymidine kinase 1 (TK1) was evaluated in differentiated (MITFhigh [microphthalmia-associated transcription factor] IGR1) and invasive (MITFmedium IGR37) melanoma cells. For inhibition of de novo pathways cells were incubated either with an irreversible TS inhibitor 5-fluoro-2'-deoxyuridine (FdUrd) or with a competitive dihydrofolate-reductase (DHFR) inhibitor methotrexate (MTX). Salvage pathway was addressed by irradiation-emitting thymidine analog [123/125 I]-5-iodo-4'-thio-2'-deoxyuridine (123/125 I-ITdU). The in vivo targeting efficiency was visualized by single-photon emission computed tomography. Pretreatment with FdUrd strongly increased the cellular uptake and the DNA incorporation of 125 I-ITdU into the mitotically active IGR37 cells. This effect was less pronounced in the differentiated IGR1 cells. In vivo, inhibition of TS led to a high and preferential accumulation of 123 I-ITdU in tumor tissue. This preclinical study presents profound rationale for development of therapeutic approach by highly efficient and selective radioactive targeting one of the crucial salvage pathways in melanomas.

PMID: 28608446 [PubMed - indexed for MEDLINE]



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Correction to: Global and Japanese regional variations in radiologist potential workload for computed tomography and magnetic resonance imaging examinations

Abstract

In Results of Abstract, the first sentence should read as: The radiologist potential workload in Japan was 2.78–4.17 times higher than those in other countries.



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LV function validation of computer-assisted interventional system for cardiac resyncronisation therapy

Abstract

Purpose

Cardiac resynchronisation therapy (CRT) is an established treatment for symptomatic patients with heart failure, a prolonged QRS duration, and impaired left ventricular (LV) function; however, non-response rates remain high. Recently proposed computer-assisted interventional platforms for CRT provide new routes to improving outcomes. Interventional systems must process information in an accurate, fast and highly automated way that is easy for the interventional cardiologists to use. In this paper, an interventional CRT platform is validated against two offline diagnostic tools to demonstrate that accurate information processing is possible in the time critical interventional setting.

Methods

The study consisted of 3 healthy volunteers and 16 patients with heart failure and conventional criteria for CRT. Data analysis included the calculation of end-diastolic volume, end-systolic volume, stroke volume and ejection fraction; computation of global volume over the cardiac cycle as well as time to maximal contraction expressed as a percentage of the total cardiac cycle.

Results

The results showed excellent correlation ( \(R^{2}\) values of \(>\,0.99\) and Pearson correlation coefficient of \(>\,0.98\) ) with comparable offline diagnostic tools.

Conclusion

Results confirm that our interventional system has good accuracy in everyday clinical practice and can be of clinical utility in identification of CRT responders and LV function assessment.



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Vital Signs in Radiologic Education

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Publication date: Available online 29 March 2018
Source:Academic Radiology
Author(s): Priscilla J. Slanetz




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A Feasibility Study of Single-inhalation, Single-energy Xenon-enhanced CT for High-resolution Imaging of Regional Lung Ventilation in Humans

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Publication date: Available online 29 March 2018
Source:Academic Radiology
Author(s): Daniel W. Pinkham, Mohammadreza Negahdar, Tokihiro Yamamoto, Erik Mittra, Maximilian Diehn, Viswam S. Nair, Paul J. Keall, Peter G. Maxim, Billy W. Loo
Rationale and ObjectivesThe objective of this study was to assess the feasibility of single-inhalation xenon-enhanced computed tomography (XeCT) to provide clinically practical, high-resolution pulmonary ventilation imaging to clinics with access to only a single-energy computed tomography scanner, and to reduce the subject's overall exposure to xenon by utilizing a higher (70%) concentration for a much shorter time than has been employed in prior studies.Materials and MethodsWe conducted an institutional review board-approved prospective feasibility study of XeCT for 15 patients undergoing thoracic radiotherapy. For XeCT, we acquired two breath-hold single-energy computed tomography images of the entire lung with a single inhalation each of 100% oxygen and a mixture of 70% xenon and 30% oxygen, respectively. A video biofeedback system for coached patient breathing was used to achieve reproducible breath holds. We assessed the technical success of XeCT acquisition and side effects. We then used deformable image registration to align the breath-hold images with each other to accurately subtract them, producing a map of lung xenon distribution. Additionally, we acquired ventilation single-photon emission computed tomography-computed tomography (V-SPECT-CT) images for 11 of the 15 patients. For a comparative analysis, we partitioned each lung into 12 sectors, calculated the xenon concentration from the Hounsfield unit enhancement in each sector, and then correlated this with the corresponding V-SPECT-CT counts.ResultsXeCT scans were tolerated well overall, with a mild (grade 1) dizziness as the only side effect in 5 of the 15 patients. Technical failures in five patients occurred because of inaccurate breathing synchronization with xenon gas delivery, leaving seven patients analyzable for XeCT and single-photon emission computed tomography correlation. Sector-wise correlations were strong (Spearman coefficient >0.75, Pearson coefficient >0.65, P value <.002) for two patients for whom ventilation deficits were visibly pronounced in both scans. Correlations were nonsignificant for the remaining five who had more homogeneous XeCT ventilation maps, as well as strong V-SPECT-CT imaging artifacts attributable to airway deposition of the aerosolized imaging agent. Qualitatively, XeCT demonstrated higher resolution and no central airway deposition artifacts compared to V-SPECT-CT.ConclusionsIn this pilot study, single-breath XeCT ventilation imaging was generally feasible for patients undergoing thoracic radiotherapy, using an imaging protocol that is clinically practical and potentially widely available. In the future, the xenon delivery failures can be addressed by straightforward technical improvements to the patient biofeedback coaching system.



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Πέμπτη, 29 Μαρτίου 2018

External beam radiation therapy to hepatocellular carcinoma involving inferior vena cava and/or right atrium: A meta-analysis and systemic review

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Publication date: Available online 29 March 2018
Source:Radiotherapy and Oncology
Author(s): Chai Hong Rim, Chul Yong Kim, Dae Sik Yang, Won Sup Yoon
PurposeHepatocellular carcinoma (HCC) involving inferior vena cava (IVC) and/or right atrium (RA) is a very rare but serious disease. The objective of this meta-analysis was to assess efficacy and safety of external beam radiotherapy (EBRT) for HCC involving IVC and/or RA.Materials and methodsSystematic search of Pubmed, MEDLINE, EMBASE, and Cochrane library published was performed. Primary endpoints were 1-year overall survival (OS) rate and 2-year OS rates. Secondary endpoints were response rate, local control (LC) rate, and grade ≥3 toxicities. According to heterogeneity evaluated with Cochran Q test and I2 statistics, meta-analysis was performed using either random or fixed model.ResultsA total of 8 studies and 9 cohorts were included, encompassing 164 patients. Pooled 1- and 2-year OS rates were 53.6% (95% CI: 45.7–61.3%) and 36.9% (95% CI: 27.2–42.4%), respectively. Pooled response rate and LC rate were 59.2% (95% CI: 39.0–76.7%) and 83.8% (95% CI: 78.8–97.1%), respectively. Only one study reported 2 grade ≥3 toxicities, an esophageal rupture and a pulmonary embolism cases. The overall rate of possible grade ≥3 complications was 1.2% (2 of 164).ConclusionsEBRT is a feasible and safe option to palliate HCC with IVC and/or RA invasion.



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Influence of deformable image registration on 4D dose simulation for extracranial SBRT: A multi-registration framework study

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Publication date: Available online 29 March 2018
Source:Radiotherapy and Oncology
Author(s): Nik Mogadas, Thilo Sothmann, Tobias Knopp, Tobias Gauer, Cordula Petersen, René Werner
Background and purposeTo evaluate the influence of deformable image registration approaches on correspondence model-based 4D dose simulation in extracranial SBRT by means of open source deformable image registration (DIR) frameworks.Material and methodsEstablished DIR algorithms of six different open source DIR frameworks were considered and registration accuracy evaluated using freely available 4D image data. Furthermore, correspondence models (regression-based correlation of external breathing signal measurements and internal structure motion field) were built and model accuracy evaluated. Finally, the DIR algorithms were applied for motion field estimation in radiotherapy planning 4D CT data of five lung and five liver lesion patients, correspondence model formation, and model-based 4D dose simulation. Deviations between the original, statically planned and the 4D-simulated VMAT dose distributions were analyzed and correlated to DIR accuracy differences.ResultsRegistration errors varied among the DIR approaches, with lower DIR accuracy translating into lower correspondence modeling accuracy. Yet, for lung metastases, indices of 4D-simulated dose distributions widely agreed, irrespective of DIR accuracy differences. In contrast, liver metastases 4D dose simulation results strongly vary for the different DIR approaches.ConclusionsEspecially in treatment areas with low image contrast (e.g. the liver), DIR-based 4D dose simulation results strongly depend on the applied DIR algorithm, drawing resulting dose simulations and indices questionable.



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Radiotherapy quality assurance for the RTOG 0834/EORTC 26053-22054/NCIC CTG CEC.1/CATNON intergroup trial “concurrent and adjuvant temozolomide chemotherapy in newly diagnosed non-1p/19q deleted anaplastic glioma”: Individual case review analysis

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Publication date: Available online 29 March 2018
Source:Radiotherapy and Oncology
Author(s): André N. Abrunhosa-Branquinho, Raquel Bar-Deroma, Sandra Collette, Enrico Clementel, Yan Liu, Coen W. Hurkmans, Loïc Feuvret, Karen Van Beek, Martin van den Bent, Brigitta G. Baumert, Damien C. Weber
BackgroundThe EORTC phase III 26053-22054/ RTOG 0834/NCIC CTG CEC.1/CATNON intergroup trial was designed to evaluate the impact on concurrent and adjuvant temozolomide chemotherapy in newly diagnosed non-1p/19q deleted anaplastic gliomas. The primary endpoint was overall survival.We report the results of retrospective individual case reviews (ICRs) for the first patient randomized per institution to detect the compliance with the study protocol.Material and methodsSixty-nine institutions were required to submit the radiotherapy plan of their first randomized patient. Full digital datasets uploaded to the EORTC server were assessed by three independent and blinded reviewers through the EORTC radiotherapy quality assurance platform.ResultsSixty-two (90%) of sixty-nine ICRs were received and assessable. Of the 62 cases, 22 were evaluated as per protocol (35.5%), 11 as acceptable variation (17.7%) and 29 were classified as unacceptable variations (46.8%). Most common unacceptable variations were related to the PTV dose (n = 19, 31%) and delineation (n = 17, 27%) processes.ConclusionsThe ICR analysis showed a significant number of unacceptable variations with potential impact on tumor control and/or toxicity profile. Prospective ICRs are encouraged for future studies to prevent and correct protocol violations before start of treatment.



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Economic data for particle therapy: Dealing with different needs in a heterogeneous landscape

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Publication date: Available online 29 March 2018
Source:Radiotherapy and Oncology
Author(s): Yolande Lievens, Klaus Nagels
BackgroundIn the light of scarce resources to be allocated for cancer care and a steady stream of costly innovations in all modalities applied to treat cancer, particle therapy needs to demonstrate its cost-utility balance to allow its positioning in the context of competing modalities. In the continuous evolving particle therapy landscape, the timely availability of appropriate economic data is crucial.MethodsEconomic data collection and compilation for particle therapy needs to follow health economic standards. Costing related analyses particularly need attention as clinical outcome data follow international standards to provide comparability. Among others, perspective, time horizons and cost categories are critical.ResultsIn this report from the "Health Economics Work Package" of the European Particle Therapy Network, the approaches commonly applied in health economic assessments are described and tailored to the specific needs of particle therapy. Data collection for cost calculation, economic evaluation and budget impact analysis are discussed.ConclusionThe presented data are intended to serve as a guidance for economic data collection, bearing in mind that in each specific case, the heterogeneous requirements of national health systems will need to be considered and assessments adapted accordingly.



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Submandibular Gland Transfer: A Potential Imaging Pitfall [HEAD & NECK]

BACKGROUND AND PURPOSE:

The Seikaly and Jha submandibular gland transfer surgery is performed to facilitate gland shielding during radiation therapy for head and neck tumors to circumvent radiation-induced xerostomia. It results in an asymmetric postsurgical appearance of the submandibular and submental spaces. Our purpose was to characterize the morphologic and enhancement characteristics of the transferred submandibular gland and identify potential pitfalls in postoperative radiologic interpretation.

MATERIALS AND METHODS:

This retrospective study identified patients with head and neck cancer who had undergone the submandibular gland transfer procedure at our institution. Chart reviews were performed to identify relevant oncologic histories and therapies. CT and MR neck imaging was reviewed to characterize morphologic and enhancement characteristics of the pre- and postoperative submandibular glands, as well as interpretive accuracy.

RESULTS:

Eleven patients with oropharyngeal and nasopharyngeal squamous cell carcinomas who underwent submandibular gland transfer were identified. The transferred glands were significantly lengthened in the anteroposterior dimension compared with contralateral glands (P < .001) and displaced anteriorly and inferiorly within the submandibular and submental spaces. Enhancement patterns of the transferred submandibular glands varied, depending on the time of imaging relative to the operation and radiation therapy. Submandibular gland transfer was acknowledged in the postoperative report in 7/11 cases. Errors in interpretation were present in 2/11 reports.

CONCLUSIONS:

After the submandibular gland transfer procedure, the submandibular and submental spaces lose their symmetric appearances as the transferred submandibular glands become lengthened and located more anteriorly and inferiorly, with variable enhancement characteristics. Familiarity with the postsurgical appearance of the transferred submandibular glands is key to accurate imaging interpretation.



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Aneurysmal Parent Artery-Specific Inflow Conditions for Complete and Incomplete Circle of Willis Configurations [INTERVENTIONAL]

BACKGROUND AND PURPOSE:

Hemodynamics are thought to play a role in intracranial aneurysm growth and rupture. Computational fluid dynamics is frequently performed to assess intra-aneurysmal hemodynamics, using generalized flow waveforms of healthy volunteers as inflow boundary conditions. The purpose of this study was to assess differences in inflow conditions for different aneurysmal parent artery locations and variations of circle of Willis configurations.

MATERIALS AND METHODS:

In a series of 96 patients with 103 aneurysms, velocity measurements were acquired using 2D phase-contrast MR imaging perpendicular to the aneurysmal parent arteries in the circle of Willis. Circle of Willis configurations were inspected for variations using multiple overlapping thin-slab-acquisition MRAs. Flow rates, velocity magnitudes, and pulsatility indices were calculated for each parent artery location in subgroups of complete and incomplete circle of Willis configurations.

RESULTS:

Flow rates, velocity magnitudes, and pulsatility indices were significantly different among aneurysmal parent arteries. Incomplete circle of Willis configurations were observed in 24% of the cases. Significantly lower basilar artery flow rates were observed in configurations with hypoplastic P1 segments. Significantly higher A1 flow rates were observed in configurations with a hypoplastic contralateral A1 segment.

CONCLUSIONS:

Inflow conditions vary substantially between aneurysmal parent arteries and circle of Willis configurations. We have created a collection of parent artery–specific inflow conditions tailored to the patient-specific circle of Willis configuration that can be used in future computational fluid dynamics studies analyzing intra-aneurysmal hemodynamics.



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Blood Flow Mimicking Aneurysmal Wall Enhancement: A Diagnostic Pitfall of Vessel Wall MRI Using the Postcontrast 3D Turbo Spin-Echo MR Imaging Sequence [ADULT BRAIN]

SUMMARY:

Our aim was to compare the detectability of aneurysmal wall enhancement in unruptured intracranial aneurysms between conventional and motion-sensitized driven equilibrium–prepared postcontrast 3D T1-weighted TSE sequences (sampling perfection with applicationoptimized contrasts by using different flip angle evolution, SPACE). Twenty-two patients with 30 unruptured intracranial aneurysms were scanned at 3T. Aneurysmal wall enhancement was more significantly detected using conventional compared with motion-sensitized driven equilibrium–prepared SPACE sequences (10/30 versus 2/30, P < .0001). Contrast-to-noise ratio measurements did not differ between conventional and motion-sensitized driven equilibrium–prepared sequences (P = .51). Flowing blood can mimic aneurysmal wall enhancement using conventional SPACE sequences with potential implications for patient care.



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Signal Change of Acute Cortical and Juxtacortical Microinfarction on Follow-Up MRI [ADULT BRAIN]

BACKGROUND AND PURPOSE:

Although the clinical importance of cortical microinfarcts has become well-recognized recently, the evolution of cortical microinfarcts on MR imaging is not fully understood. The aim of this study was to examine the temporal changes in acute cortical microinfarcts using susceptibility-weighted imaging and conventional MR imaging.

MATERIALS AND METHODS:

Patients with acute infarcts located in the cortical and/or juxtacortical region measuring ≤10 mm in axial diameter based on diffusion-weighted imaging who had a follow-up 3T MR imaging were retrospectively included in the study. All lesions did not show hypointensity on initial T2*WI. For cortical and/or juxtacortical microinfarcts detected on initial DWI, 2 neuroradiologists evaluated the follow-up MR imaging (T2WI, FLAIR, T2*WI, and SWI) and assessed lesion signal intensities and locations (cortical microinfarcts or microinfarcts with juxtacortical white matter involvement).

RESULTS:

On initial DWI, 2 radiologists observed 180 cortical and/or juxtacortical microinfarcts in 35 MR imaging examinations in 25 patients; on follow-up, the neuroradiologists identified 29 cortical microinfarcts (16%) on T2WI, 9 (5%) on FLAIR, 4 (2%) on T2*, and 97 (54%) on SWI. All cortical microinfarcts detected with any follow-up MR imaging showed hyperintensity on T2WI/FLAIR and/or hypointensity on T2*WI and SWI.

CONCLUSIONS:

SWI revealed conversion (paramagnetic susceptibility changes) of acute cortical microinfarcts, suggesting that a substantial number of cortical microinfarcts may contain hemorrhagic components.



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An Update on the Adjunctive Neurovascular Support of Wide-Neck Aneurysm Embolization and Reconstruction Trial: 1-Year Safety and Angiographic Results [INTERVENTIONAL]

BACKGROUND AND PURPOSE:

The safety and efficacy of the PulseRider for the treatment of wide-neck, bifurcation aneurysms at the basilar and carotid terminus locations were studied in a prospective trial, the Adjunctive Neurovascular Support of Wide-Neck Aneurysm Embolization and Reconstruction (ANSWER) trial, reporting on initial 6-month angiographic and clinical results. This report provides insight into the longer term durability and safety with 12-month data.

MATERIALS AND METHODS:

Aneurysms treated with the PulseRider among enrolled sites were prospectively studied. Updated 12-month data on clinical and imaging end points are included.

RESULTS:

Thirty-four patients were enrolled (29 women, 5 men) with a mean age of 60.9 years. The mean aneurysm height ranged from 2.4 to 15.9 mm with a mean neck size of 5.2 mm (range, 2.3–11.6 mm). At 1 year, there were no device migrations or symptomatic in-stent stenoses. Raymond-Roy I occlusion was achieved in 53% of cases at the time of treatment and progressed to 61% and 67% at 6 and 12 months, respectively. Adequate occlusion (Raymond-Roy I/II) progressed from 88% at 6 months to 90% at 12 months. No recanalizations were observed. There was 1 delayed ischemic event. Good outcome (mRS 0–2) was achieved in 90% of patients.

CONCLUSIONS:

The updated 1-year results from the ANSWER trial demonstrate aneurysm stability and an acceptable safety profile for aneurysms treated at the basilar apex and carotid terminus. Prospective data from a larger set of aneurysms treated at other locations are required to assess how treatment with PulseRider compares with alternatives for treating wide-neck bifurcation aneurysms.



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Parent Artery Reconstruction for Large or Giant Cerebral Aneurysms Using the Tubridge Flow Diverter: A Multicenter, Randomized, Controlled Clinical Trial (PARAT) [INTERVENTIONAL]

BACKGROUND AND PURPOSE:

Although flow diverters have been reported with favorable clinical and angiographic outcomes in various literatures, randomized trials determining their true effectiveness and safety are still in lack. The Parent Artery Reconstruction for Large or Giant Cerebral Aneurysms Using the Tubridge Flow Diverter (PARAT) trial was designed to evaluate the safety and efficacy of the Tubridge flow diverter in the treatment of large or giant aneurysms in comparison with Enterprise stent-assisted coiling.

MATERIALS AND METHODS:

This prospective, multicenter, randomized trial was conducted at 12 hospitals throughout China. Enrolled adults with unruptured large/giant intracranial aneurysms were randomly assigned (1:1) to receive either Enterprise stent-assisted coiling or Tubridge flow diverter implantation. The primary end point was complete occlusion at 6-month follow-up, while secondary end points included technical success, mortality, target vessel–related stroke, aneurysm bleeding, in-stent stenosis, parent artery occlusion, and the frequency of all adverse events.

RESULTS:

Among 185 enrolled subjects, 41 withdrew before procedure initiation. Overall, 82 subjects underwent Tubridge implantation, and 62 subjects were primarily treated with stent-assisted coiling. The results of 6-month follow-up imaging included complete occlusion rates of 75.34% versus 24.53% for the Tubridge and stent-assisted coiling groups, respectively, with a calculated common odds ratio of 9.4 (95% confidence interval, 4.14–21.38; P < .001). There was a higher, nonsignificant frequency of complications for Tubridge subjects. Multivariate analysis showed a decreased stroke rate at the primary investigational site, with a marginal P value (P = .051).

CONCLUSIONS:

This trial showed an obviously higher rate of large and giant aneurysm obliteration with the Tubridge FD over Enterprise stent-assisted coiling. However, this higher obliteration rate came at the cost of a nonsignificantly higher rate of complications. Investigational site comparisons suggested that a learning curve for flow-diverter implantation should be recognized and factored into trial designs.



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Combined hyperpolarized 13C-pyruvate MRS and 18F-FDG PET (hyperPET) estimates of glycolysis in canine cancer patients

Publication date: June 2018
Source:European Journal of Radiology, Volume 103
Author(s): Adam E. Hansen, Henrik Gutte, Pernille Holst, Helle H. Johannesen, Sofie Rahbek, Andreas E. Clemmensen, Majbritt M.E. Larsen, Christina Schøier, Jan Ardenkjaer-Larsen, Thomas L. Klausen, Annemarie T. Kristensen, Andreas Kjaer
13C Magnetic Resonance Spectroscopy (MRS) using hyperpolarized 13C-labeled pyruvate as a substrate offers a measure of pyruvate-lactate interconversion and is thereby a marker of the elevated aerobic glycolysis (Warburg effect) generally exhibited by cancer cells. Here, we aim to compare hyperpolarized [1-13C]pyruvate MRS with simultaneous 18F-2-fluoro-2-deoxy-d-glucose (FDG) PET in a cross-sectional study of canine cancer patients.MethodsCanine cancer patients underwent integrated PET/MRI using a clinical whole-body system. Hyperpolarized [1-13C]pyruvate was obtained using dissolution-DNP. 18F-FDG PET, dynamic 13C MRS, 13C MRS Imaging (MRSI) and anatomical 1H MRI was acquired from 17 patients. Apparent pyruvate-to-lactate rate constants were estimated from dynamic 13C MRS. 18F-FDG Standard Uptake Values and maximum [1-13C]lactate-to-total-13C ratios were obtained from tumor regions of interest. Following inspection of data, patients were grouped according to main cancer type and linear regression between measures of lactate generation and 18F-FDG uptake were tested within groups. Between groups, the same measures were tested for group differences.ResultsThe main cancer types of the 17 patients were sarcoma (n = 11), carcinoma (n = 5) and mastocytoma (n = 1). Significant correlations between pyruvate-to-lactate rate constants and 18F-FDG uptake were found for sarcoma patients, whereas no significant correlations appeared for carcinoma patients. The sarcoma patients showed a non-significant trend towards lower 18F-FDG uptake and higher lactate generation than carcinoma patients. However, the ratio of lactate generation to 18F-FDG uptake was found to be significantly higher in sarcoma as compared to carcinoma. The results were found both when lactate generation was estimated as an apparent pyruvate-to-lactate rate constant from dynamic 13C MRS and as an [1-13C]lactate to total 13C ratio from 13C MRSI.ConclusionsA comparison of hyperpolarized [1-13C]pyruvate MRS with simultaneous 18F-FDG PET indicate that lactate generation and 18F-FDG uptake in cancers can be related and that their relation depend on cancer type. This finding could be important for the interpretation and eventual clinical implementation of hyperpolarized 13C. In addition, the differences between the two modalities may allow for better metabolic phenotyping performing hybrid imaging in the form of hyperPET.

Graphical abstract

image


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Radiotherapy quality assurance for the RTOG 0834/EORTC 26053-22054/NCIC CTG CEC.1/CATNON intergroup trial “concurrent and adjuvant temozolomide chemotherapy in newly diagnosed non-1p/19q deleted anaplastic glioma”: Individual case review analysis

The EORTC phase III 26053-22054/ RTOG 0834/NCIC CTG CEC.1/CATNON intergroup trial was designed to evaluate the impact on concurrent and adjuvant temozolomide chemotherapy in newly diagnosed non-1p/19q deleted anaplastic gliomas. The primary endpoint was overall survival.We report the results of retrospective individual case reviews (ICRs) for the first patient randomized per institution to detect the compliance with the study protocol.

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Influence of deformable image registration on 4D dose simulation for extracranial SBRT: A multi-registration framework study

To evaluate the influence of deformable image registration approaches on correspondence model-based 4D dose simulation in extracranial SBRT by means of open source deformable image registration (DIR) frameworks.

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External beam radiation therapy to hepatocellular carcinoma involving inferior vena cava and/or right atrium: A meta-analysis and systemic review

Hepatocellular carcinoma (HCC) involving inferior vena cava (IVC) and/or right atrium (RA) is a very rare but serious disease. The objective of this meta-analysis was to assess efficacy and safety of external beam radiotherapy (EBRT) for HCC involving IVC and/or RA.

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Economic data for particle therapy: Dealing with different needs in a heterogeneous landscape

In the light of scarce resources to be allocated for cancer care and a steady stream of costly innovations in all modalities applied to treat cancer, particle therapy needs to demonstrate its cost-utility balance to allow its positioning in the context of competing modalities. In the continuous evolving particle therapy landscape, the timely availability of appropriate economic data is crucial.

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Radiation exposure for intraoperative 3D scans in a hybrid operating room: how to reduce radiation exposure for the surgical team

Abstract

Background

Hybrid operating rooms are used in different fields of surgery. In orthopedic surgery, the possibility of a 3D scan of difficult anatomical regions (spine, pelvis) showed promising results not only in navigated screw placement. The associated exposure to radiation raises questions regarding potential risks for the operating room personal and the patient. The present study focuses on scatter radiation during 3D scans in a hybrid operating room, the adjacent rooms, and methods to reduce radiation exposure.

Material and Methods

\(\hbox {RaySafe}^{\mathrm{TM}}\) i2 dosimeters were used to measure scatter radiation during 3D scans of different anatomical regions in different distances and heights in a hybrid operating room. The 3D scans were performed with a floor-based flat-panel robotic C-arm with 3D scan capability (Artis Zeego, Siemens; Germany). The 3D scans were performed using a human cadaver. The 3D scans were performed using a standard and a dose reduction protocol (DRP).

Results

The highest scatter radiation was measured during 3D scans of the pelvis on the side of the surgical assistant (39.5 Sv in height of 1 m) compared to the side of the main surgeon (23 Sv in height of 1 m). Scatter radiation was less on the position of the scrub nurse (6.8 Sv in height of 1 m) and during 3D scans of the other anatomical regions. The radiation dosage was about 66% less with the DRP. Low values of scatter radiation were measured behind a radiation protection wall and with open doors in the adjacent rooms.

Conclusion

While performing a scan scatter radiation was measured everywhere in the operating room especially during 3D scans of the pelvic girdle. Therefore, settings with lower dosage should be used whenever possible. Personnel should stand behind a radiation safety wall or leave the operating room and close the doors. For this study, six behavioral rules to avoid radiation in a hybrid operating room were established.



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Anatomical description of the umbilical arteries and impact of their ligation on pelvic and perineal vascular supply after cystectomy in women.

Related Articles

Anatomical description of the umbilical arteries and impact of their ligation on pelvic and perineal vascular supply after cystectomy in women.

Surg Radiol Anat. 2018 Mar 27;:

Authors: Chantalat E, Vaysse C, Delchier MC, Bordier B, Game X, Chaynes P, Cavaignac E, Roumiguié M

Abstract
OBJECTIVE: In radical cystectomy, the surgeon generally ligates the umbilical artery at its origin. This artery may give rise to several arteries that supply the sexual organs. Our aim was to evaluate pelvic and perineal devascularisation in women after total cystectomy.
PATIENTS AND METHODS: We carried out a prospective anatomical and radiological study. We performed bilateral pelvic dissections of fresh adult female cadavers to identify the dividing branches of the umbilical artery. In parallel, we examined and compared the pre- and postoperative imaging investigations [magnetic resonance imaging (MRI) angiography] in patients undergoing cystectomy for benign disease to quantify the loss of pelvic vascularisation on the postoperative images by identifying the occluded arteries.
RESULTS: The anatomical study together with the radiological study visualised 35 umbilical arteries (n = 70) with their branching patterns and collateral arteries. The uterine artery originated from the umbilical artery in more than 75% of cases (n = 54) of the internal pudendal artery in 34% (n = 24) and the vaginal artery in 43% (n = 30). The postoperative MRI angiograms showed pelvic devascularisation in four patients. Devascularisation was dependent on the level of surgical ligation. In the four patients with loss of pelvic vascular supply, the umbilical artery had been ligated at its origin.
CONCLUSION: The umbilical artery gives rise to various branches that supply the pelvis and perineum. If the surgeon ligates the umbilical artery at its origin during total cystectomy, there is a significant risk of pelvic and perineal devascularisation.

PMID: 29589145 [PubMed - as supplied by publisher]



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[Influence of glucocorticoid therapy on intratherapeutic biodistribution of 131I radioiodine therapy in Graves' disease].

[Influence of glucocorticoid therapy on intratherapeutic biodistribution of 131I radioiodine therapy in Graves' disease].

Nuklearmedizin. 2018 Apr;57(2):43-49

Authors: Halstenberg J, Kranert WT, Korkusuz H, Mayer A, Ackermann H, Grünwald F, Happel C

Abstract
AIM: Radioiodine therapy (RIT) is an important therapeutic method in the definitive treatment of Graves' disease (GD). However, RIT may trigger development of Graves' ophthalmopathy (GO) or exacerbate a pre-existing GO. Therefore, the procedure recommendation of the DGN (German Society of Nuclear Medicine) for RIT of benign thyroid diseases recommends an additional glucocorticoid therapy for patients with pre-existing GO. Aim of this study was to analyze the influence of a protective glucocorticoid therapy on 131I biokinetics during RIT of patients with GD.
MATERIAL AND METHODS: In this retrospective analysis 211 patients with GD who underwent RIT without additional thyreostatic medication were examined. To analyze 131I biokinetics the extrapolated maximum uptake (EMU) and the effective half-life of 131I in the thyroid were determined. Patients suffering from GO received glucocorticoids according to a fixed scheme starting one day prior to RIT, patients without GO did not receive glucocorticoids. Subsequently the ratios of values measured during RIT and those measured during radioactive iodine uptake test were compared among the groups. To take into account other factors, the groups were also compared regarding age, weight, TSH, TRAb, TgAb and TPOAb.
RESULTS: In patients with additional glucocorticoid therapy, a reduction of the median EMU from 44 % in radioiodine uptake test to 35 % during RIT was observed. The pretherapeutic (47 %) and intratherapeutic (46 %) EMU of the control group without glucocorticoids remained constant. Comparison of the change in the EMU showed a statistically significant difference between both groups (p < 0.001). Comparison of all other parameters including the effective half-life of 131I (p = 0.79) did not show any statistically significant difference.
CONCLUSION: The present study suggests that glucocorticoids affect the biokinetics of 131I by reducing its thyroidal uptake. As a result of this study, for patients without antithyroid medication undergoing glucocorticoid therapy, an adjustment of therapeutic 131I activity determined in radioiodine uptake test could be considered.

PMID: 29590674 [PubMed - in process]



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Evaluation and Management of the Child with Thyrotoxicosis.

Evaluation and Management of the Child with Thyrotoxicosis.

Recent Pat Endocr Metab Immune Drug Discov. 2018 Mar 26;:

Authors: Leung AKC, Leung AAC

Abstract
BACKGROUND: Uncontrolled thyrotoxicosis, especially in early infancy, may cause irreversible damage to the central nervous system as well as profound effects on the function of many organs. Thyrotoxicosis has multiple etiologies and treatment depends on the underlying etiology. An accurate diagnosis is essential so that appropriate treatment can be initiated without undue delay.
OBJECTIVE: To review in depth the evaluation, diagnosis, and treatment of children with thyrotoxicosis.
METHODS: A PubMed search was completed in Clinical Queries using the key terms "thyrotoxicosis" and "hyperthyroidism". The search strategy included meta-analysis, randomized controlled trials, clinical trials, observational studies, and reviews. Patents were searched using the key terms "thyrotoxicosis" and "hyperthyroidism" from https://ift.tt/N1R7MD and www.google.com/patents.
RESULTS: Graves' disease accounts for approximately 96% of pediatric cases of thyrotoxicosis. Other causes include Hashitoxicosis, toxic adenoma, toxic multinodular goiter, subacute granulomatous thyroiditis, acute suppurative thyroiditis, pituitary thyroid-stimulating hormone-secreting adenoma, pituitary thyroid hormone resistance, iodine-induced thyrotoxicosis, and drug-induced thyrotoxicosis. Familiarity of the clinical features would allow prompt diagnosis and institution of treatment. The underlying cause of thyrotoxicosis should be treated if possible. Treatment options for Graves' disease include antithyroid medications, radioiodine therapy, and surgery. Recent patents related to the management of thyrotoxicosis are discussed.
CONCLUSION: Currently, antithyroid medications are considered to be the initial treatment of choice for Graves' disease in the pediatric age group. Radioactive iodine treatment is generally used for children with poor compliance with antithyroid medications, children not in remission after 1 to 2 years of antithyroid medications, and children with a major adverse effect while receiving an antithyroid medication. Total or near-total thyroidectomy should be considered in children younger than 5 years of age who do not respond to or experience a major adverse effect to antithyroid medications. Surgery should also be considered in those with very large goiter, severe ophthalmopathy, pregnancy, persistent hyperthyroidism in spite of treatment with antithyroid medications and radioactive iodine, and personal preference.

PMID: 29589552 [PubMed - as supplied by publisher]



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Dissolution of studtite [UO2(O2)(H2O)4] in various geochemical conditions

Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Jungjin Kim, HyunJu Kim, Won-Seok Kim, Wooyong Um
This study determined the dissolution rate of studtite, (UO2)O2(H2O)4, which can be formed by reaction between H2O2 and UO22+ that leaks from spent nuclear fuel (SNF) in deep geological repositories. The batch dissolution experiments were conducted using synthesized studtite under different solution conditions with varying pHs and concentrations of HCO3 and [H2O2] in synthetic groundwater. The experimental results suggested that carbonate ligand and H2O2 in groundwater accelerated the dissolution of studtite and uranium (U) release. Above 10−5 M of H2O2 initial concentration, the released uranium concentration in solution decreased, possibly as a result of reprecipitation of studtite due to reaction between uranium and H2O2. The results will be useful to assess the comprehensive transport of uranium from both nuclear waste and SNF stored in deep geological repositories.

Graphical abstract

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Possible Balo concentric sclerosis : MRI

Case Report: 23 year old left hemiparesis. Clinical diagnosis MS. CSF OCB positive . Poor response to steroid. CEMR images are provided.MRI images  reveal rounded lesion with alternating layers of increased and reduced signal, along with diffusion restriction.  Case Submitted by Dr Rahul Rajeev, DM (Neurology std)

Quick Notes: Balo concentric sclerosis  is a rare and severe monophasic demyelinating disease, considered a subtype of multiple sclerosis, appearing as a rounded lesion with alternating layers of increased and reduced signal giving it a characteristic 'bulls eye or 'onion bulb' appearance

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FLAIR AXIAL MRI

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DW-MRI AXIAL

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CEMR

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AXIAL T2 WI

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Τετάρτη, 28 Μαρτίου 2018

Comparing the performances of Magnetic Resonance Imaging size versus pharmacokinetic parameters to predict response to neoadjuvant chemotherapy and survival in breast cancer patients

Publication date: Available online 28 March 2018
Source:Current Problems in Diagnostic Radiology
Author(s): Basak Dogan, Qing Yuan, Roland Bassett, Inanc Guvenc, Edward F. Jackson, Massimo Cristofanilli, Gary J. Whitman
PurposeTo compare the value of dynamic contrast-enhanced MRI (DCE-MRI)-pharmacokinetic (PK) parameters versus tumor volume in predicting breast cancer neoadjuvant chemotherapy response (NACR) and patient survival.Subjects and MethodsSixty-six patients with locally advanced breast cancer who underwent breast MRI monitoring of NACR were retrospectively analyzed. We compared baseline transfer constant (Ktrans), reflux rate contrast (kep), and extracellular extravascular volume fraction (ve) with the same parameters obtained at early post-chemotherapy MRI, and examined model-independent changes in time-intensity curves (maximum slope, contrast enhancement ratio, and IAUC90). Tumor size changes (tumor volume, single dimension, and RECIST) were also analyzed. The Spearman correlation test was used to assess the association between size and PK parameters, and regression analysis to assess the association with 5-year disease free survival.ResultsHigher ve values at baseline were associated with greater decreases in tumor size (P=0.008). Changes in Ktrans and IAUC90 were the strongest predictors of NACR. Changes in IAUC90 (P=0.04) and RECIST (P=0.003) were independently associated with pathological response. The only parameter significantly associated with 5-year survival was change in RECIST (P=0.001). However, there was a trend toward statistical significance for changes in ve and Ktrans, with greater changes associated with longer survival.ConclusionChanges in PK and DCE-MRI kinetic parameters may have a role in predicting NACR in breast tumors. While changes in Ktrans and IAUC90 are helpful in predicting NACR, they do not show significant association with survival. Early RECIST size change measured by MRI remains the strongest predictor of overall patient survival.



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Comparison of Natural Language Processing Rules-based and Machine-learning Systems to Identify Lumbar Spine Imaging Findings Related to Low Back Pain

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Publication date: Available online 28 March 2018
Source:Academic Radiology
Author(s): W. Katherine Tan, Saeed Hassanpour, Patrick J. Heagerty, Sean D. Rundell, Pradeep Suri, Hannu T. Huhdanpaa, Kathryn James, David S. Carrell, Curtis P. Langlotz, Nancy L. Organ, Eric N. Meier, Karen J. Sherman, David F. Kallmes, Patrick H. Luetmer, Brent Griffith, David R. Nerenz, Jeffrey G. Jarvik
Rationale and ObjectivesTo evaluate a natural language processing (NLP) system built with open-source tools for identification of lumbar spine imaging findings related to low back pain on magnetic resonance and x-ray radiology reports from four health systems.Materials and MethodsWe used a limited data set (de-identified except for dates) sampled from lumbar spine imaging reports of a prospectively assembled cohort of adults. From N = 178,333 reports, we randomly selected N = 871 to form a reference-standard dataset, consisting of N = 413 x-ray reports and N = 458 MR reports. Using standardized criteria, four spine experts annotated the presence of 26 findings, where 71 reports were annotated by all four experts and 800 were each annotated by two experts. We calculated inter-rater agreement and finding prevalence from annotated data. We randomly split the annotated data into development (80%) and testing (20%) sets. We developed an NLP system from both rule-based and machine-learned models. We validated the system using accuracy metrics such as sensitivity, specificity, and area under the receiver operating characteristic curve (AUC).ResultsThe multirater annotated dataset achieved inter-rater agreement of Cohen's kappa > 0.60 (substantial agreement) for 25 of 26 findings, with finding prevalence ranging from 3% to 89%. In the testing sample, rule-based and machine-learned predictions both had comparable average specificity (0.97 and 0.95, respectively). The machine-learned approach had a higher average sensitivity (0.94, compared to 0.83 for rules-based), and a higher overall AUC (0.98, compared to 0.90 for rules-based).ConclusionsOur NLP system performed well in identifying the 26 lumbar spine findings, as benchmarked by reference-standard annotation by medical experts. Machine-learned models provided substantial gains in model sensitivity with slight loss of specificity, and overall higher AUC.



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ESTRO ACROP guidelines for target volume definition in the treatment of locally advanced non-small cell lung cancer

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Publication date: Available online 28 March 2018
Source:Radiotherapy and Oncology
Author(s): Ursula Nestle, Dirk De Ruysscher, Umberto Ricardi, Xavier Geets, Jose Belderbos, Christoph Pöttgen, Rafal Dziadiuszko, Stephanie Peeters, Yolande Lievens, Coen Hurkmans, Ben Slotman, Sara Ramella, Corinne Faivre-Finn, Fiona McDonald, Farkhad Manapov, Paul Martin Putora, Cécile LePéchoux, Paul Van Houtte
Radiotherapy (RT) plays a major role in the curative treatment of locally advanced non-small cell lung cancer (NSCLC). Therefore, the ACROP committee was asked by the ESTRO to provide recommendations on target volume delineation for standard clinical scenarios in definitive (chemo)radiotherapy (RT) and adjuvant RT for locally advanced NSCLC. The guidelines given here are a result of the evaluation of a structured questionnaire followed by a consensus discussion, voting and writing procedure within the committee. Hence, we provide advice for methods and time-points of diagnostics and imaging before the start of treatment planning and for the mandatory and optional imaging to be used for planning itself. Concerning target volumes, recommendations are given for GTV delineation of primary tumour and lymph nodes followed by issues related to the delineation of CTVs for definitive and adjuvant radiotherapy. In the context of PTV delineation, recommendations about the management of geometric uncertainties and target motion are given. We further provide our opinions on normal tissue delineation and organisational and responsibility questions in the process of target volume delineation. This guideline intends to contribute to the standardisation and optimisation of the process of RT treatment planning for clinical practice and prospective studies.



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Practice patterns of image guided particle therapy in Europe: A 2016 survey of the European Particle Therapy Network (EPTN)

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Publication date: Available online 28 March 2018
Source:Radiotherapy and Oncology
Author(s): Alessandra Bolsi, Marta Peroni, Dante Amelio, Alexandru Dasu, Markus Stock, Iuliana Toma-Dasu, Petra Witt Nyström, Aswin Hoffmann
Background and purposeImage guidance is critical in achieving accurate and precise radiation delivery in particle therapy, even more than in photon therapy. However, equipment, quality assurance procedures and clinical workflows for image-guided particle therapy (IGPT) may vary substantially between centres due to a lack of standardization. A survey was conducted to evaluate the current practice of IGPT in European particle therapy centres.Material and methodsIn 2016, a questionnaire was distributed among 19 particle therapy centres in 12 European countries. The questionnaire consisted of 30 open and 37 closed questions related to image guidance in the general clinical workflow, for moving targets, current research activities and future perspectives of IGPT.ResultsAll centres completed the questionnaire. The IGPT methods used by the 10 treating centres varied substantially. The 9 non-treating centres were in the process to introduce IGPT. Most centres have developed their own IGPT strategies, being tightly connected to their specific technical implementation and dose delivery methods.ConclusionsInsight into the current clinical practice of IGPT in European particle therapy centres was obtained. A variety in IGPT practices and procedures was confirmed, which underlines the need for harmonisation of practice parameters and consensus guidelines.



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Susceptibility-weighted magnetic resonance imaging of cerebrovascular sequelae after radiotherapy for pediatric brain tumors

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Publication date: Available online 28 March 2018
Source:Radiotherapy and Oncology
Author(s): Marie A. Neu, Yasemin Tanyildizi, Arthur Wingerter, Nicole Henninger, Khalifa El Malki, Francesca Alt, Barbara Doerr, Heinz Schmidberger, Marcus Stockinger, Wolfgang Wagner, Stefanie Keweloh, Marc A. Brockmann, Alexandra Russo, Joerg Faber
Background and purposeDue to sensitive neuroimaging techniques, cerebrovascular complications such as cerebral microbleeds (CMB) and cerebral cavernous malformations (CCM) are increasingly recognized as considerable late effects after treatment for pediatric brain tumor. The aim of this study was to analyze CMB in a cohort of patients after cranial irradiation therapy for medulloblastoma or other pediatric brain tumors using susceptibility-weighted magnetic resonance imaging (SWI).Materials and methodsForty former pediatric brain tumor patients were enrolled in this prospective cross-sectional study and examined by cranial MRI including SWI sequences. Cerebral microbleeds, clinical symptoms and disability were evaluated.ResultsThirty-six (90%) of the examined individuals (mean follow-up age 22.2 y; mean follow-up time 13.5 y) were affected by CMB. Longer follow-up time and higher craniospinal irradiation doses correlated with higher total lesion count (p < 0.01). Thirteen patients (32.5%) presented with clinical symptoms. Individuals with CMB were more severely disabled than patients without CMB (p < 0.05).ConclusionsCerebrovascular sequelae occur frequently after treatment for pediatric brain tumor. In this study, a remarkable part of pediatric brain tumor patients presents with CMB. As a sign of vascular damage, they can cause clinical symptoms and may correspond to neurocognitive decline. Further studies are needed to standardize MRI protocols and to improve quality of long-term follow-up.



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Is accurate contouring of salivary and swallowing structures necessary to spare them in head and neck VMAT plans?

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Publication date: Available online 28 March 2018
Source:Radiotherapy and Oncology
Author(s): Alexander R. Delaney, Max Dahele, Ben J. Slotman, Wilko F.A.R. Verbakel
Background and purposeCurrent standards for organ-at-risk (OAR) contouring encourage anatomical accuracy which can be resource intensive. Certain OARs may be suitable for alternative delineation strategies. We investigated whether simplified salivary and swallowing structure contouring can still lead to good OAR sparing in automated head and neck cancer (HNC) plans.Materials and methodsFor 15 HNC patients, knowledge-based plans (KBPs) using RapidPlan™ were created using: (1) standard clinical contours for all OARs (benchmark-plans), (2) automated knowledge-based contours for the salivary glands, with standard contours for the remaining OARs (SS-plans) and (3) simplified contours (SC-plans) consisting of quick-to-draw tubular structures to account for the oral cavity, salivary glands and swallowing muscles. Individual clinical OAR contours in a RapidPlan™ model were combined to create composite salivary/swallowing structures. These were matched to tube-contours to create SC-plans. All plans were compared based on dose to anatomically accurate clinical OAR contours.ResultsSalivary gland delineation in SS-plans required on average 2 min, compared with 7 min for manual delineation of all tubular-contours. Automated atlas-based contours overlapped with, on average, 71% of clinical salivary gland contours while tube-contours overlapped with 95%/75%/93% of salivary gland/oral cavity/swallowing structure contours. On average, SC-plans were comparable to benchmark-plans and SS-plans, with average differences in composite salivary and swallowing structure dose ≤2 Gy and <1 Gy respectively.ConclusionsSimplified-contours could be created quickly and resulted in clinically acceptable HNC VMAT plans. They can be combined with automated planning to facilitate the implementation of advanced radiotherapy, even when resources are limited.



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The role of shear wave elastography on evaluation of the rigidity changes of corpus cavernosum penis in venogenic erectile dysfunction

Publication date: June 2018
Source:European Journal of Radiology, Volume 103
Author(s): Ailin Cui, Lili Xu, Jingjing Mu, Minghui Tong, Cheng Peng, Tingting Wu
ObjectiveThe goal of this study was to evaluate the effect of shear wave elastography (SWE) on the measurement of rigidity changes of penile erection in venogenic erectile dysfunction (ED) and in rigidity alterations of corpus cavernosum penis with age in normal population.MethodsThe study was a prospective analysis of 81 patients referred to the department of urology with complaints of ED as well as 35 healthy volunteers. SWE was performed on the corpus cavernosum penis (CCP) in the flaccid state of healthy group. The patients were divided into venogenic ED (31 patients) and non-vascular ED (neither arterial insufficiency nor venogenic dysfunction) (36 patients) by performing color doppler ultrasonography in association with intracavernous injection (ICI). SWE measurements were performed in CCP in the flaccid state, after 15–20 min and 25–30 min of ICI in both patients groups. Differences between groups were compared.ResultsAge was significantly negatively associated with SWE values of CCP among three groups (healthy group: r = −0.584, p < 0.05; venogenic ED group: r = −0.468, p < 0.05; non-vascular ED group: r = −0.539, p < 0.05). There was no significant difference between the SWE values of three groups in the flaccid state (p > 0.05). The mean SWE values of CCP were significantly lower in the erectile state (15–20 min after ICI) compared with the flaccid state in two patients groups (p < 0.05). The mean SWE values of CCP after ICI increased with time (from 15–20 min to 25–30 min) in patients with venogenic ED (p < 0.05), while the SWE values of CCP after ICI did not statistically significantly differ with time in patients with non-vascular ED (p > 0.05).ConclusionSWE is expected to be a promising approach in terms of the etiological diagnosis of ED and the quantitative evaluation of alternations of penile structures with age.



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Resting-state functional connectivity MRI analysis in Human Immunodeficiency Virus and Hepatitis C Virus co-infected subjects. A pilot study

Publication date: May 2018
Source:European Journal of Radiology, Volume 102
Author(s): Simone Corgiolu, Luigi Barberini, Jasjit S. Suri, Antonella Mandas, Diego Costaggiu, Paola Piano, Fulvio Zaccagna, Pierleone Lucatelli, Antonella Balestrieri, Luca Saba
Background and purposeHepatitis C virus (HCV) co-infection's role on cognitive impairment of human immunodeficiency virus (HIV) positive patients is still debated and functional neuroimaging evaluation on this matter is lacking. To provide further insight about HCV's neuro-effects on HIV associated neurocognitive disorder (HAND), we performed a pilot resting state (RS) functional connectivity magnetic resonance imaging (fcMRI) study to find eventual functional connectivity alteration that could reflect HCV related cognitive performance degradation.MethodsEighteen patients (8 HIV, 10 HIV + HCV), either impaired or not impaired, were assessed with RS fcMRI. A statistic model including cognitive testing results was elaborated during data processing to evaluate brain networks alteration related to actual cognitive status in patients.ResultsStatistically significant different patterns of connectivity were found: HCV co-infection modified 17 ROIs' connectivity with 45 supra-threshold connections (p-FDR min 0.0022, max 0.0497). ROIs most involved were right pallidum, brainstem, vermian lobules 1–2 and right cerebellar lobule 10. Graph theory analysis did not demonstrate significant difference between networks, but HCV related modifications at ROI's local level were found, with particular involvement of ROIs of frontal lobe, basal ganglia and cerebellum. Increased fronto-striatal dysfunctions have been already reported as consequences of HCV infection and could reflect an additive effect. Cerebellar alterations are associated with HIV and HAND, but not with HCV infection, suggesting a synergic effect of HCV.ConclusionOur study demonstrates RS fcMRI can help to understand the interactions between HIV and HCV co-infection, and our preliminary results suggest synergic effects of HCV in HIV-related brain functional modification.

Graphical abstract

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Peptide Receptor Radionuclide Therapy and the Treatment of Gastroentero-pancreatic Neuroendocrine Tumors: Current Findings and Future Perspectives

Abstract

Purpose and Methods

Patients with inoperable and metastasized neuroendocrine tumors (NETs), particularly those with grades 1 and 2, usually receive treatment with somatostatin analogues (SSAs). Peptide receptor radionuclide therapy (PRRT) has gained momentum over the past two decades in patients who progress on SSAs. 177Lu-DOTATATE is currently the most widely used radiopeptide for PRRT. We reviewed the recent evidence on PRRT and the treatment of gastroentero-pancreatic neuroendocrine tumors (GEP-NETs).

Results

177Lu-DOTATATE can be used as neoadjuvant treatment in patients with inoperable GEP-NETs, who might be candidate for surgery after treatment and as adjuvant therapy after surgical intervention. Combination treatments of PRRT with chemotherapy or targeted agents as well as combinations of radionuclides in patients with NETs have been explored over the last few years. The majority of patients with NETs experience partial response or have disease stabilization, a small percentage has complete response, while some 30% of patients, however, will have disease progression. The safety and efficacy of retreatment with extra cycles of PRRT as salvage therapy have been evaluated in small retrospective series.

Conclusion

Overall, there is evidence that disease control and quality of life improve significantly after 117Lu PRRT therapy. Clinical trials on this therapy are scarce, and there is a need for further studies to establish proper management guidelines.



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