Induction chemotherapy for locally advanced nasopharyngeal carcinoma treated with concurrent chemoradiation: A systematic review and meta-analysis

Publication date: Available online 16 March 2018
Source:Radiotherapy and Oncology
Author(s): Teng Hwee Tan, Yu Yang Soon, Timothy Cheo, Francis Ho, Lea Choung Wong, Jeremy Tey, Ivan W.K. Tham
PurposeTo determine if the addition of induction chemotherapy (IC) to concurrent chemoradiation (CCRT) in locally advanced nasopharyngeal carcinoma (LA-NPC) can improve survival.MethodsWe performed a meta-analysis of both randomized controlled trials (RCTs) and observational studies (OBS) to compare the effects of addition of IC to CCRT versus (vs) CCRT alone on overall survival (OS), progression free survival (PFS), distant metastasis-free survival (DMFS) and adverse events (AE) in LA-NPC. We searched MEDLINE for eligible studies comparing IC plus CCRT vs CCRT for LA-NPC from Jan 1996 to May 2017. We selected RCTs and OBS that included patients with non-metastatic, LA-NPC who received IC followed by CCRT or CCRT alone. Three reviewers independently assessed the abstracts for eligibility. We assessed the methodological quality of the included studies using the MERGE criteria. We performed the meta-analysis with random effects model. We used the GRADE approach to appraise the quality of evidence from RCTs. The primary outcome was OS; secondary outcomes included PFS, DMFS and AE.ResultsWe found six RCTs and five OBS including 2802 patients with low to moderate risk of bias in their methodological quality. There was high quality evidence from the RCTs that IC improved PFS (HR 0.69, 95% CI 0.57–0.84, P = 0.0003, I² = 0%) and OS (HR 0.77, 95% CI 0.60–0.98, P = 0.03, I² = 0%) significantly and was associated with more frequent AE. The estimates of IC effects from RCTs and OBS were similar (PFS HR 0.69 vs 0.71, interaction P (IP) = 0.92; OS HR 0.77 vs 0.58, IP = 0.27).ConclusionsIC delays disease progression and improves survival significantly for LA-NPC treated with CCRT, and was associated with more toxicity. There were no divergent results between RCTs and OBS. IC followed by CCRT can be considered one of the standard treatment options for LA-NPC.



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High accuracy dosimetry with small pieces of Gafchromic films

Publication date: March–April 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 2
Author(s): Ryszard Dąbrowski, Izabela Drozdyk, Paweł Kukołowicz
AimTo investigate the influence of several factors on the accuracy of dose measurements and feasibility of application of small Gafchromic detectors for postal audit.BackgroundOur experience showed that precision of dose measurements with small pieces of Gafchromic films may be significantly improved.Materials and methodsGafchromic films with dimensions of 1×1, 2×2 and 3×3cm² were exposed to 6MV X-rays at dose levels of 50cGy-210cGy. The single- and multichannel methods (MM) were used for dose measurements. Detectors were scanned with an Epson V750PRO flatbed colour scanner. For 1×1 and larger detector sizes, separate calibration curves were established. The influence of the following factors was investigated: the heterogeneity of Gafchromic detectors group for single- and MM, ambient thermal detector conditions, the dose delivered on the measurement accuracy, application of two separate calibration curves for the smallest and larger pieces of films.ResultsThe MM improves significantly the precision of dose measurement. The uncertainty attributed to detector active layer differences and scanner instabilities was about 1cGy (1 StDev) regardless of dose and detector size. The ambient temperature of the environment in which films were stored after irradiation influenced the dose reading. Significant difference of transmission for detectors sized 1×1 and 2×2cm² was observed. The maximal difference between applied dose and dose reading performed was 1.1%.ConclusionsThe MM with a scaling protocol leads to a very high precision of dose measurements. The ambient thermal detector environment causes significant changes of measured signal. The detector size has relevant impact on dose reading.



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Compliance with bladder protocol during concurrent chemoradiation for cancer of the cervix and its impact on enteritis: A prospective observational study

Publication date: March–April 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 2
Author(s): Sweta Bandanatham, Janaki Manur Gururajachar, Mohan Kumar Somashekar
AimThis prospective study aims to assess the compliance with bladder protocol and the correlation with enteritis during pelvic radiation.BackgroundBladder protocol is routinely used for patients undergoing pelvic radiation to reduce radiation enteritis. It is very difficult to maintain constant volume especially in the last two weeks due to radiation enteritis and cystitis.Materials and methodsHistologically proven 35 cervical cancer patients treated with concurrent chemoradiation in a tertiary care center were the subjects of this prospective study. Following CT simulation and after every fraction, patients were asked to void urine in a calibrated urine container and the volume was documented. Patients were assessed for the highest grade of radiation enteritis weekly as per common toxicity criteria. The mean voided urine volume was correlated with the radiation enteritis.ResultsThe mean urine volume at planning CT scan was 295.85±300ml (SD) with a range of 75–650. At the end of treatment, it was reduced to 233.14±250ml (range 50–400ml), a reduction by 21% (p<0.001). The maximum grade of enteritis was grade I (11%), II (11.4%), III (3–29%) in week 1,2 and 3–5, respectively with a p value of <0.001. A mean urine volume of 230ml was associated with grade III enteritis in the third week.ConclusionsUrine output volume measured using a calibrated container is a simple, efficient and practical method to monitor bladder distension thereby reducing enteritis in cervical cancer patients treated with concurrent chemoradiation.



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Interfractional diaphragm changes during breath-holding in stereotactic body radiotherapy for liver cancer

Publication date: March–April 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 2
Author(s): Daisuke Kawahara, Shuichi Ozawa, Takeo Nakashima, Shintaro Tsuda, Yusuke Ochi, Takuro Okumura, Hirokazu Masuda, Kazunari Hioki, Tathsuhiko Suzuki, Yoshimi Ohno, Tomoki Kimura, Yuji Murakami, Yasushi Nagata
Aim and backgroundIGRT based on bone matching may produce a large target positioning error in terms of the reproducibility of expiration breath-holding on SBRT for liver cancer. We evaluated the intrafractional and interfractional errors using the diaphragm position at the end of expiration by utilising Abches and analysed the factor of the interfractional error.Materials and methodsIntrafractional and interfractional errors were measured using a couple of frontal kV images, planning computed tomography (pCT) and daily cone-beam computed tomography (CBCT). Moreover, max–min diaphragm position within daily CBCT image sets with respect to pCT and the maximum value of diaphragm position difference between CBCT and pCT were calculated.ResultsThe mean±SD (standard deviation) of the intra-fraction diaphragm position variation in the frontal kV images was 1.0±0.7mm in the C-C direction. The inter-fractional diaphragm changes were 0.4±4.6mm in the C-C direction, 1.4±2.2mm in the A-P direction, and −0.6±1.8mm in the L-R direction. There were no significant differences between the maximum value of the max–min diaphragm position within daily CBCT image sets with respect to pCT and the maximum value of diaphragm position difference between CBCT and pCT.ConclusionsResidual intrafractional variability of diaphragm position is minimal, but large interfractional diaphragm changes were observed. There was a small effect in the patient condition difference between pCT and CBCT. The impact of the difference in daily breath-holds on the interfractional diaphragm position was large or the difference in daily breath-holding heavily influenced the interfractional diaphragm change.



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Dosimetry of the left anterior descending coronary artery in left breast cancer patients treated with postoperative external radiotherapy

Publication date: March–April 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 2
Author(s): Adela Poitevin-Chacón, Jessica Chávez-Nogueda, Rubí Ramos Prudencio, Alejandro Calvo Fernández, Alejandro Rodríguez Laguna, Jesús Linares, Julio César Martínez
AimTo evaluate the dose distribution to the left anterior descending (LAD) coronary artery in patients treated with postoperative three-dimensional conformal radiotherapy (3DCRT).BackgroundPostoperative radiotherapy may increase the risk of heart disease, particularly in patients with left-sided breast cancer. Clinical data on doses to the LAD are limited.Materials and methodsRetrospective study of 14 patients who underwent postoperative 3DCRT for left breast cancer in 2014. All data were retrieved from medical records. Means, medians, ranges, and percentages were calculated.ResultsThe mean dose to the LAD in patients with V25<1% was 0.12cGy. Dmean, Dmax and V25 to the heart were, respectively, 3.7Gy (range, 0.9–4.18), 40.3Gy (9.28–62.9), and 1.59cGy. The mean Dmean and Dmax values in the sample were 9.71Gy and 33.2Gy, respectively. The maximum dose to the LAD (D2%) ranged from 3.66 to 53.01Gy. Due to the spacing of the CT slices (5mm), it was not possible to completely contour the entire artery. The mean dose to the heart (3.3Gy) was considered acceptable.ConclusionsThe maximum dose to the LAD was as high as 53Gy, suggesting an increased risk of cardiac morbidity. This study underscores the value of contouring the LAD and the value of the breath hold technique to reduce maximum cardiac doses. Smaller CT cuts (2.5mm) can improve contouring. Larger studies with long-term follow up are needed to determine the radiation tolerance dose for the LAD.



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Thymic tumors and results of radiotherapy

Publication date: March–April 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 2
Author(s): Sureyya Sarıhan, Ahmet Sami Bayram, Cengiz Gebitekin, Omer Yerci, Deniz Sıgırlı
AimThe aim of this study was to evaluate thymic epithelial tumors (TETs) for treatment outcomes and prognostic factors on survival.BackgroundTETs are very rare neoplasms and multidisciplinary approach is recommended according to prognostic factors.Materials and methodsBetween 1995 and 2013, 31 patients were treated with median 5400cGy (range: 1620–6596cGy) radiotherapy (RT). Eleven patients received adjuvant or concurrent chemotherapy. There were 25 thymomas, 4 thymic carcinomas and 2 thymic neuroendocrin carcinomas. According to Masaoka, staging and WHO classification, cases were divided to good (n: 10), moderate (n: 9) and poor (n: 12) prognostic risk groups. Survival was calculated from diagnosis.ResultsIn January 2016, 22 cases were alive with median 51.5 months (range: 2–170.5) follow-up. Recurrences were observed in 29% of patients in median 29.5 months (range: 6.5–105). Local control, mean overall (OS) and disease-free survival (DFS) rates were 86%, 119 and 116 months, respectively. There was a significant difference for R0 vs. R+ resection (81% vs. 43%, p=0.06, and 69% vs. 46%, p=0.05), Masaoka stage I–II vs. III–IV (75% vs. 52%, p=0.001, and 75% vs. 37%, p<0.001), and also prognostic risk groups (100% vs. 89% vs. 48%, p=0.003, and 100% vs. 87% vs. 27%, p=0.004) in terms of 5-year OS and DFS, respectively.ConclusionIn our study, prognostic risk stratification was shown to be a significant predictor of survival. There is a need to investigate subgroups that may or may not benefit from adjuvant RT.



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Accuracy evaluation of distance inverse square law in determining virtual electron source location in Siemens Primus linac

Publication date: March–April 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 2
Author(s): Hamid Shafaei Douk, Mahmoud Reza Aghamiri, Mahdi Ghorbani, Bagher Farhood, Mohsen Bakhshandeh, Hamid Reza Hemmati
AimThe aim of this study is to evaluate the accuracy of the inverse square law (ISL) method for determining location of virtual electron source (SVir) in Siemens Primus linac.BackgroundSo far, different experimental methods have presented for determining virtual and effective electron source location such as Full Width at Half Maximum (FWHM), Multiple Coulomb Scattering (MCS), and Multi Pinhole Camera (MPC) and Inverse Square Law (ISL) methods. Among these methods, Inverse Square Law is the most common used method.Materials and methodsFirstly, Siemens Primus linac was simulated using MCNPX Monte Carlo code. Then, by using dose profiles obtained from the Monte Carlo simulations, the location of SVir was calculated for 5, 7, 8, 10, 12 and 14MeV electron energies and 10cm×10cm, 15cm×15cm, 20cm×20cm and 25cm×25cm field sizes. Additionally, the location of SVir was obtained by the ISL method for the mentioned electron energies and field sizes. Finally, the values obtained by the ISL method were compared to the values resulted from Monte Carlo simulation.ResultsThe findings indicate that the calculated SVir values depend on beam energy and field size. For a specific energy, with increase of field size, the distance of SVir increases for most cases. Furthermore, for a special applicator, with increase of electron energy, the distance of SVir increases for most cases. The variation of SVir values versus change of field size in a certain energy is more than the variation of SVir values versus change of electron energy in a certain field size.ConclusionAccording to the results, it is concluded that the ISL method can be considered as a good method for calculation of SVir location in higher electron energies (14MeV).



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Editorial board

Publication date: March–April 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 2





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Assessment of the Monitor Unit Objective tool for VMAT in the Eclipse treatment planning system

Publication date: March–April 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 2
Author(s): Sara Jiménez-Puertas, David Sánchez-Artuñedo, Marcelino Hermida-López
AimThis work aims to achieve the highest possible monitor units (MU) reduction using the MU Objective tool included in the Eclipse treatment planning system, while preserving the plan quality.BackgroundThe treatment planning system Eclipse (Varian Medical Systems, Palo Alto, CA) includes a control mechanism for the number of monitor units of volumetric modulated arc therapy (VMAT) plans, named the MU Objective tool.Material and methodsForty prostate plans, 20 gynecological plans and 20 head and neck plans designed with VMAT were retrospectively studied. Each plan (base plan) was optimized without using the MU Objective tool, and it was re-optimized with different values of the Maximum MU (MaxMU) parameter of the MU Objective tool. MU differences were analyzed with a paired samples t-test and changes in plan quality were assessed with a set of parameters for OARs and PTVs.ResultsThe average relative MU difference (ΔMU¯) considering all treatment sites, was the highest when MaxMU=400 (−4.2%, p<0.001). For prostate plans, the lowest ΔMU¯ was obtained (−3.7%, p<0.001). For head and neck plans ΔMU¯ was −7.3% (p<0.001) and for gynecological plans ΔMU¯ was 7.0% (p=0.002). Although similar MU reductions were observed for both sites, for some gynecological plans maximum differences were greater than 10%. All the assessed parameters for PTVs and OARs sparing showed average differences below 2%.ConclusionFor the three studied clinical sites, establishing MaxMU=400 led to the optimum MU reduction, maintaining the original dose distribution and dosimetric parameters practically unaltered.



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Extended localization and adaptive dose calculation using HU corrected cone beam CT: Phantom study

Publication date: March–April 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 2
Author(s): K Mohamathu Rafic, S Amalan, B S Timothy Peace, B Paul Ravindran
Background and aimThe practicability of computing dose calculation on cone beam CT (CBCT) has been widely investigated. In most clinical scenarios, the craniocaudal scanning length of CBCT is found to be inadequate for localization. This study aims to explore extended tomographic localization and adaptive dose calculation strategies using Hounsfield unit (HU) corrected CBCT image sets.Materials and methodsPlanning CT (pCT) images of the Rando phantom (T12-to-midthigh) were acquired with pelvic-protocol using Biograph CT-scanner. Similarly, half-fan CBCT were acquired with fixed parameters using Clinac2100C/D linear accelerator integrated with an on-board imager with 2-longitudinal positions of the table. For extended localization and dose calculation, two stitching strategies viz., one with "penumbral-overlap" (S1) and the other with "no-overlap" (S2) and a local HU-correction technique were performed using custom-developed MATLAB scripts. Fluence modulated treatment plans computed on pCT were mapped with stitched CBCT and the dosimetric analyses such as dose-profile comparison, 3D-gamma (γ) evaluation and dose-volume histogram (DVH) comparison were performed.ResultsLocalizing scanning length of CBCT was extended by up to 15cm and 16cm in S1 and S2 strategies, respectively. Treatment plan mapping resulted in minor variations in the volumes of delineated structures and the beam centre co-ordinates. While the former showed maximum variations of −1.4% and −1.6%, the latter showed maximum of 1.4mm and 2.7mm differences in anteroposterior direction in S1 and S2 protocols, respectively. Dosimetric evaluations viz., dose profile and DVH comparisons were found to be in agreement with one another. In addition, γ-evaluation results showed superior pass-rates (≥98.5%) for both 3%/3mm dose-difference (DD) and distance-to-agreement (DTA) and 2%/2mm DD/DTA criteria with desirable dosimetric accuracy.ConclusionCone beam tomographic stitching and local HU-correction strategies developed to facilitate extended localization and dose calculation enables routine adaptive re-planning while circumventing the need for repeated pCT.



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Does ITV vaginal procedure ensure dosimetric coverage during IMRT of post-operative gynaecological tumours without instructions concerning rectal filling?

Publication date: March–April 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 2
Author(s): Ramona Verges, Alexandra Giraldo, Alejandro Seoane, Elisabet Toral, M. Carmen Ruiz, Ariadna Pons, Jordi Giralt
AimTo find out whether the internal target volume (ITV) vaginal procedure ensures dosimetric coverage during intensity-modulated radiation therapy (IMRT) of post-operative gynaecological tumours without instructions on rectal filling.BackgroundThe ITV vaginal procedure does not necessarily include all movements of the bladder, and does not include changes in the rectal volume. We should know if the vaginal ITV is a useful tool in maintaining CTV coverage during treatment.Materials and methodsA retrospective analysis of 24 patients treated between July 2012 and July 2014 with adjuvant IMRT for gynaecological cancer. All patients underwent empty and full bladder CT on simulation (CT-planning) and three weeks later (CT-control). ITV displacement was measured and the 3D vector was calculated. ITV coverage was then evaluated by comparing the volume covered by the prescription isodose on both CT's. Patients were asked to have full bladder but they did not follow recommendations for the rectum.ResultsThe mean 3D vector was 0.64±0.32cm (0.09–1.30). The mean ITV coverage loss was 5.8±5.7% (0–20.2). We found a significant positive correlation between the 3D vector and the loss of coverage (Pearson correlation, r=0.493, 95% CI: 0.111–0.748, p=0.0144). We did not find any significant correlation between the bladder and rectal parameters with the 3D vector and loss of dosimetric coverage. We found a trend between the maximum rectal diameter in CT-planning and 3D vector (r=0.400, 95% CI: −0.004 to 0.692, p=0.0529).ConclusionITV vaginal procedure contributed to ensuring a good dose coverage without instructions on rectal filling.



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Adenomas – Genetic factors in colorectal cancer prevention

Publication date: March–April 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 2
Author(s): Kycler Witold, Kubiak Anna, Trojanowski Maciej, Janowski Jakub
Colorectal cancer is the second most common type of cancer both in Europe and Poland. During the last 30 years more than a 3-fold increase has been observed in Poland due to environmental and genetic factors. Almost all colorectal malignancies are related to the formation and malignant transformation of colorectal dysplasia and adenoma. Efforts aiming to decrease the number of colorectal cancer deaths are focused on the disease early detection. Genetic diagnosis for hereditary syndromes predisposing to colorectal cancer has been developed and is a part of the routine treatment. Most cancers are sporadic. They often develop from polyps in the colon. In addition to the genetic events described in the 1990s, showing the adenoma transformation into carcinoma that has been a prime example of malignant transformation for a long time, there are also other possibilities of neoplastic transformation. The recognition of colorectal cancer risk factors make sense as their nature is lifestyle- and diet-related. In this review paper those risk factors are presented and the prevention of colorectal cancer is discussed taking into account genetic factors.



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Editorial board

Publication date: January–February 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 1





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Energy spectrum and dose enhancement due to the depth of the Lipiodol position using flattened and unflattened beams

Publication date: January–February 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 1
Author(s): Daisuke Kawahara, Shuichi Ozawa, Akito Saito, Tomoki Kimura, Tatsuhiko Suzuki, Masato Tsuneda, Sodai Tanaka, Kazunari Hioki, Takeo Nakashima, Yoshimi Ohno, Yuji Murakami, Yasushi Nagata
AimLipiodol was used for stereotactic body radiotherapy combining trans arterial chemoembolization. Lipiodol used for tumour seeking in trans arterial chemoembolization remains in stereotactic body radiation therapy. In our previous study, we reported the dose enhancement effect in Lipiodol with 10× flattening-filter-free (FFF). The objective of our study was to evaluate the dose enhancement and energy spectrum of photons and electrons due to the Lipiodol depth with flattened (FF) and FFF beams.MethodsFF and FFF for 6MV beams from TrueBeam were used in this study. The Lipiodol (3×3×3cm³) was located at depths of 1, 3, 5, 10, 20, and 30cm in water. The dose enhancement factor (DEF) and the energy fluence were obtained by Monte Carlo calculations of the particle and heavy ion transport code system (PHITS).ResultsThe DEFs at the centre of Lipiodol with the FF beam were 6.8, 7.3, 7.6, 7.2, 6.1, and 5.7% and those with the FFF beam were 20.6, 22.0, 21.9, 20.0, 12.3, and 12.1% at depths of 1, 3, 5, 10, 20, and 30cm, respectively, where Lipiodol was located in water. Moreover, spectrum results showed that more low-energy photons and electrons were present at shallow depth where Lipiodol was located in water. The variation in the low-energy spectrum due to the depth of the Lipiodol position was more explicit with the FFF beam than that with the FF beam.ConclusionsThe current study revealed variations in the DEF and energy spectrum due to the depth of the Lipiodol position with the FF and FFF beams. Although the FF beam could reduce the effect of energy dependence due to the depth of the Lipiodol position, the dose enhancement was overall small. To cause a large dose enhancement, the FFF beam with the distance of the patient surface to Lipiodol within 10cm should be used.



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Dosimetric evaluation of image based brachytherapy using tandem ovoid and tandem ring applicators

Publication date: January–February 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 1
Author(s): Ramya Rangarajan
AimThe aim of the study is to evaluate the differences in dosimetry between tandem-ovoid and tandem-ring gynaecologic brachytherapy applicators in image based brachytherapy.BackgroundTraditionally, tandem ovoid applicators were used to deliver dose to tumor in intracavitary brachytherapy. Tandem-ring, tandem-cylinder and hybrid intracavitary, interstitial applicators are also used nowadays in cervical cancer brachytherapy.Methods and materials100 CT datasets of cervical cancer patients (stage IB2 – IIIB) receiving HDR application (50 tandem-ovoid and 50 tandem-ring) were studied. Brachytherapy was delivered using a CT-MRI compatible tandem-ovoid (50 patients) and a tandem-ring applicator (50 patients). DVHs were calculated and D2cc was recorded for the bladder and rectum and compared with the corresponding ICRU point doses. The point B dose, the treated volume, high dose volume and the treatment time were recorded and compared for the two applicators.ResultsThe mean D2cc of the bladder with TR applicator was 6.746Gy. TO applicator delivered a mean D2cc of 7.160Gy to the bladder. The mean ICRU bladder points were 5.60 and 5.63Gy for TR and TO applicator, respectively. The mean D2cc of the rectum was 4.04Gy and 4.79Gy for TR and TO applicators, respectively. The corresponding ICRU point doses were 5.10Gy and 5.66Gy, respectively.ConclusionsThe results indicate that the OAR doses assessed by DVH criteria were higher than ICRU point doses for the bladder with both tandem-ovoid and tandem-ring applicators whereas DVH based dose was lower than ICRU dose for the rectum. The point B dose, the treated volume and high dose volume was found to be slightly higher with the tandem-ovoid applicator. The mean D2cc dose for the bladder and rectum was lower with tandem-ring applicators. The clinical implication of the above dosimetric differences needs to be evaluated further.



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Radiotherapy setup displacements in breast cancer patients: 3D surface imaging experience

Publication date: January–February 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 1
Author(s): Ana Cravo Sá, Ana Fermento, Dalila Neves, Sara Ferreira, Teresa Silva, Carina Marques Coelho, Aude Vaandering, Ana Roma, Sérgio Quaresma, Emmanuel Bonnarens
AimIn this study, we intend to compare two different setup procedures for female breast cancer patients.BackgroundImaging in radiotherapy provides a precise localization of the tumour, increasing the accuracy of the treatment delivery in breast cancer.Materials and methodsTwenty breast cancer patients who underwent whole breast radiotherapy (WBRT) were selected for this study. Patients were divided into two groups of ten. Group one (G1) was positioned by tattoos and then the patient positioning was adjusted with the aid of AlignRT (Vision RT, London, UK). In group two (G2), patients were positioned only by tattoos. For both groups, the first 15 fractions were analyzed, a daily kilovoltage (kV) cone beam computed tomography (CBCT) image was made and then the rotational and translational displacements and, posteriorly, the systematic (Σ) and random (σ) errors were analyzed.ResultsThe comparison of CBCT displacements for the two groups showed a statistically significant difference in the translational left–right (LR) direction (ρ=0.03), considering that the procedure with AlignRT system has smaller lateral displacements. The results of systematic (Σ) and random (σ) errors showed that for translational displacements the group positioned only by tattoos (G2) demonstrated higher values of errors when compared with the group positioned with the aid of AlignRT (G1).ConclusionsAlignRT could help the positioning of breast cancer patients; however, it should be used with another imaging method.



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Acknowledgement of reviewers

Publication date: January–February 2018
Source:Reports of Practical Oncology & Radiotherapy, Volume 23, Issue 1





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Induction chemotherapy for locally advanced nasopharyngeal carcinoma treated with concurrent chemoradiation: A systematic review and meta-analysis

To determine if the addition of induction chemotherapy (IC) to concurrent chemoradiation (CCRT) in locally advanced nasopharyngeal carcinoma (LA-NPC) can improve survival.

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Table of Contents (Pantone 286 C)

Publication date: April 2018
Source:Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, Volume 125, Issue 4





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Society Page (Headings are Pantone 286 C; logos are 4/color)

Publication date: April 2018
Source:Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, Volume 125, Issue 4





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Information for Readers (Pantone 286 C)

Publication date: April 2018
Source:Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, Volume 125, Issue 4





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Editorial Board (Pantone 286 C)

Publication date: April 2018
Source:Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, Volume 125, Issue 4





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10 Years of Nephrogenic Systemic Fibrosis: A Comprehensive Analysis of Nephrogenic Systemic Fibrosis Reports Received by a Pharmaceutical Company from 2006 to 2016

Objectives The aim of this study was to critically assess the evaluation and categorization process for nephrogenic systemic fibrosis (NSF) based on reports received by Bayer from 2006 to 2016. Materials and Methods A total of 779 NSF reports received by Bayer globally from 2006 to 2016 were included in the analysis. Arlington Medical Resources provided gadolinium-based contrast agent (GBCA) market share. Reports were conservatively categorized based on the Cowper/Girardi criteria. A statistical model simulated the impact of market share and market introduction on the number of unconfounded reports. Results For all reports, reported onset of disease ranged from 1996 and 2012. Of 779 reports, 325 involved a Bayer product only, 208 involved only products from other companies (or unknown GBCA), and 246 involved both Bayer and non-Bayer products. Most of all reports (86%) originated from the United States. Through 2006, Magnevist and Omniscan dominated the US market (>80% combined market share). All other GBCAs with fewer NSF reports comprised the remaining combined market share of less than 20% or were introduced after May 2007, after safety recommendations came into effect. A total of 563 reports (220 single-agent and 343 multiagent reports) involved Magnevist. In at least 150 of the 343 reports, a different GBCA (Omniscan, 118; OptiMARK, 15; MultiHance, 6; and macrocyclic agent, 11) showed the closest temporal relationship to onset of NSF-like symptoms. The simulation model demonstrated that patients receiving a GBCA with lower market share and late market introduction are less likely to be observed in an unconfounded setting. Conclusions Year of market introduction, as well as US market share in 2000 to 2007, greatly influenced the absolute number of NSF reports for each GBCA, their a priori probability to cause NSF, as well as their a priori probability to be associated with unconfounded cases of NSF. Variability in case interpretation and pharmacovigilance approaches also influence the absolute number of unconfounded cases and should therefore not be used for comparative risk assessments. This should be primarily based on objective product parameters such as structure, stability, pharmacokinetics, and dose. This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. Received for publication December 21, 2017; and accepted for publication, after revision, February 7, 2018. Conflicts of interest and source of funding: All authors are employees of Bayer AG, except for Susanne Schwenke. The study was funded by Bayer AG. Correspondence to: Jan Endrikat, MD, PhD, Bayer AG, Müllerstr. 178, 13353 Berlin, Germany. E-mail: jan.endrikat@bayer.com. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.

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A hybrid image fusion system for endovascular interventions of peripheral artery disease

Abstract

Purpose

Interventional endovascular treatment has become the first line of management in the treatment of peripheral artery disease (PAD). However, contrast and radiation exposure continue to limit the feasibility of these procedures. This paper presents a novel hybrid image fusion system for endovascular intervention of PAD. We present two different roadmapping methods from intra- and pre-interventional imaging that can be used either simultaneously or independently, constituting the navigation system.

Methods

The navigation system is decomposed into several steps that can be entirely integrated within the procedure workflow without modifying it to benefit from the roadmapping. First, a 2D panorama of the entire peripheral artery system is automatically created based on a sequence of stepping fluoroscopic images acquired during the intra-interventional diagnosis phase. During the interventional phase, the live image can be synchronized on the panorama to form the basis of the image fusion system. Two types of augmented information are then integrated. First, an angiography panorama is proposed to avoid contrast media re-injection. Information exploiting the pre-interventional computed tomography angiography (CTA) is also brought to the surgeon by means of semiautomatic 3D/2D registration on the 2D panorama. Each step of the workflow was independently validated.

Results

Experiments for both the 2D panorama creation and the synchronization processes showed very accurate results (errors of 1.24 and \(2.6 \pm 1.4\)  mm, respectively), similarly to the registration on the 3D CTA (errors of \(1.5 \pm 0.7\)  mm), with minimal user interaction and very low computation time. First results of an on-going clinical study highlighted its major clinical added value on intraoperative parameters.

Conclusion

No image fusion system has been proposed yet for endovascular procedures of PAD in lower extremities. More globally, such a navigation system, combining image fusion from different 2D and 3D image sources, is novel in the field of endovascular procedures.

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Diagnostic value of 3DFLAIR in clinical practice for the detection of infratentorial lesions in Multiple Sclerosis in regard to dual echo T2 sequences

Publication date: Available online 15 March 2018
Source:European Journal of Radiology
Author(s): Salem Hannoun, Damien Heidelberg, Roula Hourani, Thi Thuy Trang Nguyen, Jean-Christophe Brisset, Sylvie Grand, Stéphane Kremer, Fabrice Bonneville, Charles R.G. Guttmann, Vincent Dousset, François Cotton
Background and purposeThe aim of this prospective study is to investigate and evaluate in clinical practice the diagnostic impact of 3DFLAIR in regards to 2DT2/PD in terms of infratentorial lesions detection in multiple sclerosis (MS).Material and Methods164 MS patients from the OFSEP database were reviewed retrospectively. MR examinations were performed on 1.5T or 3T systems from four different centers. Infratentorial lesions were counted and allocated to different regions of the posterior fossa by three raters independently (junior resident, resident with an expertise in neuroradiology, and senior neuro-radiologist) on the 3DFLAIR and 2DT2/PD. Both sequences do not have the same spatial resolution but reflect what is recommended by most of the consensus and done in clinical practice.ResultsWith an overall number of 528 for Rater-1 and 798 for Rater-2 infratentorial lesions, 3DFLAIR had a significantly higher number of lesions detected than 2DT2/PD (303 for Rater-1 and 370 for Rater-2). The prevalence of trigeminal lesions detected by using 3DFLAIR was also significantly higher than 2DT2/PD. ROC analysis showed 3DFLAIR to be more specific and sensitive than 2DT2/PD. An overall difference between all three Raters has been observed. The more the Rater is experienced the more lesions he detects.ConclusionAlong with the radiologist ability to detect lesions based on his level of experience, the OFSEP optimized 3DFLAIR can significantly improve infratentorial lesion detection in MS compared to 2DT2/PD. This is important in MS follow-up that takes into account new lesions number to adapt patients' treatment.



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Possible XOR fallacy - case report of combined foramen sternale with an osseous sternal knife stab injury

Publication date: Available online 15 March 2018
Source:Journal of Forensic Radiology and Imaging
Author(s): Wolf Schweitzer, Garyfalia Ampanozi, Lars Ebert, Michael Thali, Damaris Fröhlich Knaute
This case report details a sternal finding that first was reported as penetrating knife stab wound. It was one in a series of 24 otherwise relatively superficial skin stab wounds allegedly performed by a single assailant within the scope of a single attack. The effort required to penetrate the sternum with a knife appears to be considerably higher than to inflict relatively superficial skin and soft tissue penetration. This initially raised suspicion of another person contributing to the attack, or, a different weapon being used. After reviewing the clinical CT scans, we identified the combination of a preexisting sternal foramen with a marginal fracture and concluded that the sternal "penetration" was in keeping with the depth of the other 23 stab wounds. None of the injuries were lethal, the victim survived the attack. Assuming that a knife penetration fracture of a sternum and a foramen sternale are mutually exclusive constitutes an exclusive-OR fallacy (XOR fallacy).



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10 Years of Nephrogenic Systemic Fibrosis: A Comprehensive Analysis of Nephrogenic Systemic Fibrosis Reports Received by a Pharmaceutical Company from 2006 to 2016

Objectives The aim of this study was to critically assess the evaluation and categorization process for nephrogenic systemic fibrosis (NSF) based on reports received by Bayer from 2006 to 2016. Materials and Methods A total of 779 NSF reports received by Bayer globally from 2006 to 2016 were included in the analysis. Arlington Medical Resources provided gadolinium-based contrast agent (GBCA) market share. Reports were conservatively categorized based on the Cowper/Girardi criteria. A statistical model simulated the impact of market share and market introduction on the number of unconfounded reports. Results For all reports, reported onset of disease ranged from 1996 and 2012. Of 779 reports, 325 involved a Bayer product only, 208 involved only products from other companies (or unknown GBCA), and 246 involved both Bayer and non-Bayer products. Most of all reports (86%) originated from the United States. Through 2006, Magnevist and Omniscan dominated the US market (>80% combined market share). All other GBCAs with fewer NSF reports comprised the remaining combined market share of less than 20% or were introduced after May 2007, after safety recommendations came into effect. A total of 563 reports (220 single-agent and 343 multiagent reports) involved Magnevist. In at least 150 of the 343 reports, a different GBCA (Omniscan, 118; OptiMARK, 15; MultiHance, 6; and macrocyclic agent, 11) showed the closest temporal relationship to onset of NSF-like symptoms. The simulation model demonstrated that patients receiving a GBCA with lower market share and late market introduction are less likely to be observed in an unconfounded setting. Conclusions Year of market introduction, as well as US market share in 2000 to 2007, greatly influenced the absolute number of NSF reports for each GBCA, their a priori probability to cause NSF, as well as their a priori probability to be associated with unconfounded cases of NSF. Variability in case interpretation and pharmacovigilance approaches also influence the absolute number of unconfounded cases and should therefore not be used for comparative risk assessments. This should be primarily based on objective product parameters such as structure, stability, pharmacokinetics, and dose. This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. Received for publication December 21, 2017; and accepted for publication, after revision, February 7, 2018. Conflicts of interest and source of funding: All authors are employees of Bayer AG, except for Susanne Schwenke. The study was funded by Bayer AG. Correspondence to: Jan Endrikat, MD, PhD, Bayer AG, Müllerstr. 178, 13353 Berlin, Germany. E-mail: jan.endrikat@bayer.com. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.

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Unilateral duplicated abducens nerve coursing through both the sphenopetroclival venous gulf and cavernous sinus: a case report.

Unilateral duplicated abducens nerve coursing through both the sphenopetroclival venous gulf and cavernous sinus: a case report.

Surg Radiol Anat. 2018 Mar 15;:

Authors: Coquet T, Lefranc M, Chenin L, Foulon P, Havet É, Peltier J

Abstract
In this anatomy report, we describe the first case of abducens nerve duplication limited to the sphenopetroclival venous gulf and the cavernous sinus. The objective point of division of the two duplicated roots was localized at the gulfar face of the dural porus, just distal to the unique cisternal trunk of the abducens nerve, as it pierced the petroclival dural mater. In the gulfar segment, both roots traveled through a variant of Dorello's canal called the "petrosphenoidal canal" and remained separated through the posterior half of the cavernous sinus. Both roots finally fused in the anterior half of the cavernous sinus to innervate the lateral rectus muscle as a single trunk. Although many variants of the abducens nerve have been reported over the recent decades, this anatomic variation has never been previously described and enriches the continuum of abducens nerve variations reported in the literature data. Awareness of this variation is crucial for neurosurgeons, especially during clival or petrosal surgical approaches used for resection of skull base chordomas.

PMID: 29541802 [PubMed - as supplied by publisher]

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Morphometric properties of the levator scapulae, rhomboid major, and rhomboid minor in human fetuses.

Morphometric properties of the levator scapulae, rhomboid major, and rhomboid minor in human fetuses.

Surg Radiol Anat. 2018 Mar 15;:

Authors: Beger O, Dinç U, Beger B, Uzmansel D, Kurtoğlu Z

Abstract
PURPOSE: The main objective of this study is to showcase the growth dynamics of levator scapulae, rhomboid major, and rhomboid minor algebraically, to help plan surgeries on newborns and young infants.
METHODS: Twenty-five formalin-fixed fetuses (11 male-14 female) with a mean gestational age of 21.80 ± 2.61 (range 18-27) weeks present in the inventory of Mersin University Faculty of Medicine Anatomy Department were dissected. Surface area of levator scapulae, rhomboid major, and rhomboid minor was calculated using digital image analysis software; width and length parameters were measured using digital calipers.
RESULTS: Neither sex nor side significant differences were observed in relation with the numerical data of levator scapulae, rhomboid major, and rhomboid minor (p > 0.05). Algebraic parameters such as surface area, width and length were detected to exhibit a linear growth from 18th to 27th week. Linear functions for levator scapulae, rhomboid major and rhomboid minor surface areas were obtained as y = - 136.871 + 10.598 × age (weeks), y = - 480.567 + 33.147 × age (weeks) and y = - 128.090 + 8.843 × age (weeks), respectively.
CONCLUSION: The results and data of this study can potentially be beneficial in planning of surgeries for many infancy diseases such as trapezius paralysis, obstetrical brachial plexus palsy, Sprengel's disease, or winged scapula. Linear functions calculated in this study are expected to provide a better understanding of the growth dynamics of levator scapulae, rhomboid major, and rhomboid minor in fetal term and more precise estimation of muscle sizes.

PMID: 29541801 [PubMed - as supplied by publisher]

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Automated surgical skill assessment in RMIS training

Abstract

Purpose

Manual feedback in basic robot-assisted minimally invasive surgery (RMIS) training can consume a significant amount of time from expert surgeons' schedule and is prone to subjectivity. In this paper, we explore the usage of different holistic features for automated skill assessment using only robot kinematic data and propose a weighted feature fusion technique for improving score prediction performance. Moreover, we also propose a method for generating 'task highlights' which can give surgeons a more directed feedback regarding which segments had the most effect on the final skill score.

Methods

We perform our experiments on the publicly available JHU-ISI Gesture and Skill Assessment Working Set (JIGSAWS) and evaluate four different types of holistic features from robot kinematic data—sequential motion texture (SMT), discrete Fourier transform (DFT), discrete cosine transform (DCT) and approximate entropy (ApEn). The features are then used for skill classification and exact skill score prediction. Along with using these features individually, we also evaluate the performance using our proposed weighted combination technique. The task highlights are produced using DCT features.

Results

Our results demonstrate that these holistic features outperform all previous Hidden Markov Model (HMM)-based state-of-the-art methods for skill classification on the JIGSAWS dataset. Also, our proposed feature fusion strategy significantly improves performance for skill score predictions achieving up to 0.61 average spearman correlation coefficient. Moreover, we provide an analysis on how the proposed task highlights can relate to different surgical gestures within a task.

Conclusions

Holistic features capturing global information from robot kinematic data can successfully be used for evaluating surgeon skill in basic surgical tasks on the da Vinci robot. Using the framework presented can potentially allow for real-time score feedback in RMIS training and help surgical trainees have more focused training.

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European Society of Neuroradiology (ESNR)

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XLVI ANNUAL MEETING OF SPANISH SOCIETY OF NEURORADIOGY

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Pediatric astrocytic tumor grading: comparison between arterial spin labeling and dynamic susceptibility contrast MRI perfusion

Abstract

Purpose

The aim of this study was to compare arterial spin labeling (ASL) and dynamic susceptibility contrast (DSC) MRI perfusion with respect to diagnostic performance in tumor grading in pediatric patients with low- and high-grade astrocytic tumors (AT).

Methods

We retrospectively analyzed 37 children with histologically proven treatment naive low- and high-grade AT who underwent concomitant pre-operative ASL and DSC MRI perfusion. Studies were performed on a 1.5 T scanner, and a pulsed technique was used for ASL. DSC data were post-processed with a leakage correction software. Normalization of tumor perfusion parameters was performed with contralateral normal appearing gray matter. Normalized cerebral blood volume (nCBV) values in the most perfused area of each neoplasm were compared with normalized DSC-derived cerebral blood flow (nDSC-CBF) and ASL-derived cerebral blood flow (nASL-CBF) data, and correlated with WHO tumor grade. Statistics included Pearson's chi-square and Mann-Whitney U tests, Spearman's rank correlation, and receiver operating characteristic (ROC) analysis.

Results

A significant correlation was demonstrated between DSC and ASL data (p < 0.001). Significant differences in terms of DSC and ASL data were found between low- and high-grade AT (p < 0.001). ROC analysis demonstrated similar performances between all parameters in predicting tumor grade (nCBV: AUC 0.96, p < 0.001; nDSC-CBF: AUC 0.98, p < 0.001; nASL-CBF: AUC 0.96, p < 0.001).

Conclusions

Normalized pulsed ASL performed with a 1.5 T scanner provides comparable results to DSC MRI perfusion in pediatric AT and may allow distinction between high- and low-grade AT.

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Volumetric assessment of tumor size changes in pediatric low-grade gliomas: feasibility and comparison with linear measurements

Abstract

Purpose

We report a retrospective comparison between bi-dimensional RANO criteria and manual volumetric segmentation (MVS) in pediatric low-grade gliomas.

Methods

MRI FLAIR or T1 post contrast images were used for assessment of tumor response. Seventy patients were included in this single center study, for each patient two scans were assessed ("time 0" and "end of therapy") and response to therapy was evaluated for both methods. Inter-reader variability and average time for volumetric assessment were also calculated.

Results

Fourteen (20%) of the 70 patients had discordant results in terms of response assessment between the bi-dimensional measurements and MVS. All volumetric response assessments were in keeping with the subjective analysis of tumor (radiology report). Of the 14 patients, 6 had stable disease (SD) on MVS and progressive disease (PD) on 2D assessment, 5 patients had SD on MVS and partial response (PR) on 2D assessment, 2 patients had PD on MVS and SD on 2D assessment, and 1 patient had PR on MVS and SD on 2D analysis. The number of discordant results rises to 21(30%) if minor response is integrated in the response assessment. MVS was relatively fast and showed high inter-reader concordance.

Conclusion

Our analysis shows that therapeutic response classification may change in a significant number of children by performing a volumetric tumor assessment. Furthermore, MVS is not particularly time consuming and has very good inter-reader concordance.

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Impact of intracranial artery calcification on cerebral hemodynamic changes

Abstract

Purpose

Intracranial artery calcification (IAC) has been demonstrated to be correlated with ischemic stroke, cognitive decline, and other vascular events by accumulating evidences from both Western and Asian populations. The proposed study aimed to investigate its potential mechanisms by evaluating the blood flow velocity and pulsatility index (PI) of cerebral arteries.

Methods

Consecutive ischemic stroke patients admitted to the Prince of Wales Hospital were recruited after excluding those with atrial fibrillation or poor temporal window. Quantitative measurements of IAC severity were assessed on brain CT scans. Transcranial Doppler (TCD) ultrasonography was performed to evaluate the blood flow velocity of the middle cerebral artery (MCA) and vertebral-basilar artery (VBA).

Results

In total, 318 patients were analyzed. Spearman's correlation analysis demonstrated both high MCA systolic flow velocity and high MCA PI were correlated with IAC Agatston score, p < 0.001 individually. Similar correlation was also found between IAC Agatston score and high VBA velocity/high VBA PI, p ≤ 0.001 individually. Multiple logistic regression analysis showed IAC Agatston score was an independent risk factor for high MCA velocity (OR 1.533; 95% CI 1.235–1.903), high VBA velocity (OR 1.964; 95% CI 1.381–2.794), and high VBA PI (OR 1.200; 95% CI 1.016–1.418), respectively.

Conclusion

Heavier IAC might cause generalized artery flow velocity changes and increased pulsatility index, which may indicate high resistance within cerebrovasculature.

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Brain computed tomography using iterative reconstruction to diagnose acute middle cerebral artery stroke: usefulness in combination of narrow window setting and thin slice reconstruction

Abstract

Purpose

The purpose of this study is to determine whether iterative model reconstruction (IMR) optimized for brain CT could improve the detection of acute stroke in the setting of thin image slices and narrow window settings.

Methods

We retrospectively reviewed 27 patients who presented acute middle cerebral artery (MCA) stroke. Images were reconstructed using filtered back projection (FBP; 1- and 5-mm slice thickness) and IMR (1 mm thickness), and contrast-to-noise ratios (CNRs) of infarcted and non-infarcted areas were compared. To analyze the performance of acute MCA stroke detection, we used receiver operating characteristic (ROC) curve techniques and compared 5-mm FBP with standard and narrow window settings, and 1-mm FBP and IMR with narrow window settings.

Results

The CNR in 1-mm IMR (1.1 ± 1.0) was significantly higher than in 5- (0.8 ± 0.7) and 1-mm FBP (0.4 ± 0.4) (p < 0.001). Furthermore, the average area under the ROC curve was significantly higher with 1-mm IMR with narrow window settings (0.90, 95% CI: 0.86, 0.94) than it was with 5-mm FBP (0.78, 95% CI: 0.72, 0.83).

Conclusion

The combination of thin image slices and narrow window settings under IMR reconstruction provide better diagnostic performance for acute MCA stroke than conventional reconstruction methods.

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Age-related early/late variations of functional connectivity across the human lifespan

Abstract

Purpose

Many questions remain regarding how the brain develops, matures, and ages across the lifespan. The functional connectivity networks in the resting-state brain can reflect many of the characteristic changes in the brain that are associated with increasing age. Functional connectivity has been shown to be time-dependent over the course of a lifespan and even over the course of minutes. The lifespan strategies of all cognitive networks and how dynamic functional connectivity is associated with age are unclear.

Methods

In this paper, studies employing both linear and quadratic models to define new specific lifespan strategies, including early/late increase/decrease models, were conducted to explore the lifespan functional changes. A large data sample was retrieved from the publicly available data from the Nathan Kline Institute (N = 149 and ages 9–85). Both static and dynamic functional connectivity indexes were calculated including the static functional connectivity, the mean of the dynamic functional connectivity and variations in dynamic functional connectivity.

Results

The between-network connectivity results revealed early increases in the default-mode (DF) and cingulo-opercular network (CO)-associated network connectivities and a late increase in the fronto-parietal (FP)-associated network connectivity. These results depicted various lifespan strategies for different development stages and different cognitive networks across the lifespan. Additionally, the static FC and mean dynamic FC exhibited consistent results, and their variation exhibited a constant decrease with age across the entire age range.

Conclusion

These results (FDR-corrected p value < 0.05) suggest that the early/late variations in lifespan strategies could reflect an association between varied and complex circumstances and brain development.

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Torgny Greitz, MD, PhD, FACR, Professor of Neuroradiology, Emeritus

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Glioma grading by dynamic susceptibility contrast perfusion and 11 C-methionine positron emission tomography using different regions of interest

Abstract

Purpose

The use of dynamic susceptibility contrast (DSC) perfusion and ¹¹C-methionine positron emission tomography (MET-PET) for glioma grading is currently not standardized. The purpose of this study was to identify regions of interest (ROIs) that enable the best performance and clinical applicability in both methods, as well as to evaluate the complementarity of DSC perfusion and MET-PET in spatial hotspot definition.

Methods

In 41 patient PET/MRI datasets, different ROIs were drawn: in T2-hyperintense tumour, in T2-hyperintense tumour and adjacent oedema and in tumour areas with contrast enhancement, altered perfusion or pathological radiotracer uptake. The performance of DSC perfusion and MET-PET using the different ROIs to distinguish high- and low-grade gliomas was assessed. The spatial overlap of hotspots identified by DSC perfusion and MET-PET was assessed visually.

Results

ROIs in T2 fluid attenuated inversion recovery (FLAIR) sequence-hyperintense tumour revealed the most significant differences between high- and low-grade gliomas and reached the highest diagnostic performance in both DSC perfusion (p = 0.046; area under the curve = 0.74) and MET-PET (p = 0.007; area under the curve = 0.80). The combination of methods yielded an area under the curve of 0.80. Hotspots were completely overlapped in one half of the patients, partially overlapped in one third of the patients and present in only one method in approximately 20% of the patients.

Conclusions

For multi-parametric examinations with DSC perfusion and MET-PET, we recommend an ROI definition based on T2-hyperintense tumour. DSC perfusion and MET-PET contain complementary information concerning the spatial hotspot definition.

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European Society of Neuroradiology (ESNR)

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CTA/V detection of bilateral sigmoid sinus dehiscence and suspected idiopathic intracranial hypertension in unilateral pulsatile tinnitus

Abstract

Purpose

This aimed to evaluate the prevalence and extent of bilateral sigmoid sinus dehiscence (SSD) and to explore the presence of idiopathic intracranial hypertension (IIH) in patients with unilateral pulsatile tinnitus (PT) with CTA/V.

Methods

Sixty PT patients (52 females; 40.4 ± 11.6 years [20–72]) who underwent CTA/V and 30 non-PT patients (27 females; 38.4 ± 14.7 years [12–62]) were enrolled in this study. The primary outcome measure was the radiographic presence of SSD. The index of transverse sinus stenosis (ITSS) was obtained by multiplying the stenosis scale values for each transverse sinus, and once was ≥ 4, the presence of IIH was suspected.

Results

The prevalence and extent of SSD on symptomatic side (78%; maximum transverse diameter, MTD 0.49 ± 0.23; maximum vertical diameter, MVD 0.50 ± 0.26 cm) were significantly higher and larger than those on asymptomatic side (50%, P < 0.001; MTD 0.35 ± 0.18, P = 0.006; MVD 0.30 ± 0.15 cm, P < 0.001) in the study group and those (20%, P < 0.001; MTD 0.36 ± 0.18, P = 0.073; MVD 0.30 ± 0.22 cm, P < 0.048) in the control group. The presence of SSD showed significant correlation with both PT (logistic regression analysis, OR 4.167 [1.450–11.97]; P = 0.008) and suspected IIH (OR 16.25 [1.893–139.5]; P = 0.011).

Conclusion

In PT patients, SSD has a significant correlation with PT and a potential correlation with IIH.

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XLVI ANNUAL MEETING OF SPANISH SOCIETY OF NEURORADIOGY

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MR findings of the orbit in patients with Vogt–Koyanagi–Harada disease

Abstract

Purpose

We aimed to evaluate the MR findings of the orbit in patients with Vogt–Koyanagi–Harada disease (VKHD).

Methods

We included 14 patients with clinically diagnosed VKHD, who underwent orbital MR imaging before treatment between May 2011 and August 2017. The mean duration from initial symptom onset to MR imaging was 16 days (range, 2–36 days). Fat-suppressed gadolinium-enhanced T1-weighted images were obtained in six patients. We retrospectively assessed the choroids and Tenon's capsules for the presence of thickening on unenhanced images and abnormal enhancement on contrast-enhanced images.

Results

Bilateral choroidal thickening was observed in 14 patients (100%) on T1-weighted images and in 12 patients (85.7%) on T2-weighted images. Choroidal thickening showed posterior pole predominance in 11 patients (78.6%) and diffusely distributed in the remaining three patients (21.4%). Bilateral Tenon's capsule thickening was observed in five patients (35.7%) on T1-weighted images and in 14 patients (100%) on T2-weighted images. On contrast-enhanced images, the choroids and Tenon's capsules were abnormally enhanced in six patients (100%).

Conclusion

MR imaging sensitively detected abnormalities of the choroids and Tenon's capsules in patients with VKHD. Bilaterality and predominant posterior pole distribution were characteristic of choroidal VKHD.

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Usefulness of perfusion- and diffusion-weighted imaging to differentiate between pilocytic astrocytomas and high-grade gliomas: a multicenter study in Japan

Abstract

Purpose

Imaging findings of pilocytic astrocytoma (PA) vary widely, sometimes resembling those of high-grade glioma (HGG). This study aimed to identify the imaging parameters that can be used to differentiate PA from HGG.

Methods

Altogether, 60 patients with PAs and 138 patients with HGGs were included in the study. Tumor properties and the presence of hydrocephalus, peritumoral edema, and dissemination were evaluated. We also measured the maximum relative cerebral blood flow (rCBF_max) and volume (rCBV_max) and determined the minimum apparent diffusion coefficient (ADC_min) in the tumor's solid components. The relative T1 (rT1), T2 (rT2), and contrast-enhanced T1 (rCE-T1) intensity values were evaluated. Parameters were compared between PAs and HGGs using the Mann–Whitney U test. Receiver operating characteristic (ROC) curve analysis was also used to evaluate these imaging parameters. A value of P < .05 was considered to indicate significance.

Results

Intratumoral hemorrhage and calcification were observed in 10.0% and 21.7% of PAs, respectively. The rCBF_max and rCBV_max values were significantly lower in PAs (0.50 ± 0.35, 1.82 ± 1.21) than those in HGGs (2.98 ± 1.80, 9.54 ± 6.88) (P < .0001, P = .0002, respectively). The ADC_min values were significantly higher in PAs (1.36 ± 0.56 × 10⁻³ mm²/s) than those in HGGs (0.86 ± 0.37 × 10⁻³ mm²/s) (P < .0001). ROC analysis showed that the best diagnostic performance was achieved with rCBF_max.

Conclusion

The rCBF_max, rCBV_max, and ADC_min can differentiate PAs from HGGs.

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Cardiac-gated intravoxel incoherent motion diffusion-weighted magnetic resonance imaging for the investigation of intracranial cerebrospinal fluid dynamics in the lateral ventricle: a feasibility study

Abstract

Purpose

Intravoxel incoherent motion (IVIM) in diffusion-weighted magnetic resonance imaging (DW-MRI) attributes the signal attenuation to the molecular diffusion and to a faster pseudo-diffusion. Purpose of the study was to demonstrate the feasibility of IVIM for the investigation of intracranial cerebrospinal fluid (CSF) dynamics.

Methods

Cardiac-gated DW-MRI images with fifteen b-values (0–1300s/mm²) along three orthogonal directions (mediolateral (ML), anteroposterior (AP), and craniocaudal (CC)) were acquired during maximum systole and diastole in 10 healthy volunteers (6 males, mean age 36 ± 15 years). A pixel-wise bi-exponential fitting with an iterative nonparametric algorithm was carried out to calculate the following parameters: diffusion coefficient (D), fast diffusion coefficient (D*), and fraction of fast diffusion (f). Region of interest measurements were performed in both lateral ventricles. Comparison of IVIM parameters was performed among two cardiac cycle acquisitions and among the diffusion-encoding directions using a paired Student's t test.

Results

f significantly (p < 0.05) depended on the diffusion-encoding direction and on the cardiac cycle (diastole AP 0.30 ± 0.13, ML 0.22 ± 0.12, CC 0.26 ± 0.17; systole AP 0.45 ± 0.17, ML 0.34 ± 0.15, CC 0.40 ± 0.21). Neither a cardiac cycle nor a direction dependency was found among mean D values (which is in line with the expected intraventricular isotropic diffusion) and D* values (p > 0.05 each).

Conclusion

The fraction of fast diffusion from IVIM is feasible to detect a direction-dependent and cardiac-dependent pulsatile CSF flow within the lateral ventricles allowing for quantitative monitoring of CSF dynamics. This technique might provide opportunities to further investigate the pathophysiology of various neurological disorders involving altered CSF dynamics.

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High dynamic range ultrasound imaging

Abstract

Purpose

High dynamic range (HDR) imaging is a popular computational photography technique that has found its way into every modern smartphone and camera. In HDR imaging, images acquired at different exposures are combined to increase the luminance range of the final image, thereby extending the limited dynamic range of the camera. Ultrasound imaging suffers from limited dynamic range as well; at higher power levels, the hyperechogenic tissue is overexposed, whereas at lower power levels, hypoechogenic tissue details are not visible. In this work, we apply HDR techniques to ultrasound imaging, where we combine ultrasound images acquired at different power levels to improve the level of detail visible in the final image.

Methods

Ultrasound images of ex vivo and in vivo tissue are acquired at different acoustic power levels and then combined to generate HDR ultrasound (HDR-US) images. The performance of five tone mapping operators is quantitatively evaluated using a similarity metric to determine the most suitable mapping for HDR-US imaging.

Results

The ex vivo and in vivo results demonstrated that HDR-US imaging enables visualizing both hyper- and hypoechogenic tissue at once in a single image. The Durand tone mapping operator preserved the most amount of detail across the dynamic range.

Conclusions

Our results strongly suggest that HDR-US imaging can improve the utility of ultrasound in image-based diagnosis and procedure guidance.

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