Multi-institutional Comparison Research Articles

Commercial Hybrid Graft versus Traditional Arch Replacement with Frozen Elephant Trunk: A Multi-Institutional Comparison

Commercial Hybrid Graft versus Traditional Arch Replacement with Frozen Elephant Trunk: A Multi-Institutional Comparison

Inter-laboratory comparison of real-time quaking-induced conversion (RT-QuIC) for the detection of chronic wasting disease prions in white-tailed deer retropharyngeal lymph nodes.

The rapid geographic spread of chronic wasting disease (CWD) in white-tailed deer (WTD; Odocoileus virginianus) increases the need for the development and validation of new detection tests. Real-time quaking-induced conversion (RT-QuIC) has emerged as a sensitive tool for CWD prion detection, but federal approval in the United States has been challenged by practical constraints on validation and uncertainty surrounding RT-QuIC robustness between laboratories. To evaluate the effect of inter-laboratory variation on CWD prion detection using RT-QuIC, we conducted a multi-institution comparison on a shared anonymized sample set. We hypothesized that RT-QuIC can accurately and reliably detect the prions that cause CWD in postmortem samples from medial retropharyngeal lymph node (RPLN) tissue despite variation in laboratory protocols. Laboratories from 6 U.S. states (Michigan, Minnesota, Missouri, New York, Pennsylvania, Wisconsin) were enlisted to compare the use of RT-QuIC in determining CWD prion status (positive or negative) among 50 anonymized RPLNs of known prion status. Our sample set included animals of 3 codon 96 WTD genotypes known to affect CWD progression and detection (G96G, G96S, S96S). All 6 laboratories successfully identified the true disease status consistently for all 3 tested codon 96 genotypes. Our results indicate that RT-QuIC is a suitable test for the detection of CWD prions in RPLN tissues in several genotypes of WTD.

Unlocking the Potential of Computed Tomography-Guided Tracers in Pinpointing Lung Lesions during Surgery: A Collaborative Multi-Institutional Journey.

Background: Multiple techniques exist for the preoperative localization of small, deeply located solid or subsolid pulmonary nodules to guide limited thoracoscopic resection. This study aims to conduct a multi-institutional comparison of three different tomography-guided tracers' methods. Methods: A retrospective multicenter cross-sectional study was conducted. All patients suitable for CT-guided tracers with microcoil (GROUP1, n = 58), hook wire (GROUP2, n = 86), or bioabsorbable hydrogel plug (GROUP3, n = 33) were scheduled for video-assisted thoracoscopic wedge resection. Outcome variables: successful nodule localization, safety, and the feasibility of the tracers' placement. A χ2 test or Fisher's test for expected numbers less than five and a Kruskal-Wallis test were used to analyze the categorical and continuous variables, respectively. For the power calculations, we used G*Power version 3.1.9.6. Results: One hundred seventy-seven patients underwent the localization and resection of 177 nodules detected with three different CT-guided tracers. A significant difference was recorded for cancer history (p = 0.030), respiratory function, Charlson comorbidity index (p = 0.018), lesion type (p < 0.0001), distance from pleura surface (p < 0.0001), and time between preoperative CT-guided tracers and surgical procedures (p < 0.0001). Four post-procedural complications were recorded and in GROUP2, four cases of tracer dislocations occurred. Finally, hook wire group was associated with the shortest surgical time (93 min, p = 0.001). Conclusions: All methods were feasible and efficient, resulting in a 100% success rate for the microcoils and the bioabsorbable hydrogel plugs and a 94.2% success rate for the hook wires. Our results highlight the need to choose a technique that is less stressful for the patient and helps the surgeon by extending the approach to deep nodules and resecting over the course of several days from deployment.

A multi-institutional comparison of retrospective deformable dose accumulation for online adaptive magnetic resonance-guided radiotherapy

Background and PurposeApplication of different deformable dose accumulation (DDA) solutions makes institutional comparisons after online-adaptive magnetic resonance-guided radiotherapy (OA-MRgRT) challenging. The aim of this multi-institutional study was to analyze accuracy and agreement of DDA-implementations in OA-MRgRT. Material and MethodsOne gold standard (GS) case deformed with a biomechanical-model and five clinical cases consisting of prostate (2x), cervix, liver, and lymph node cancer, treated with OA-MRgRT, were analyzed. Six centers conducted DDA using institutional implementations. Deformable image registration (DIR) and DDA results were compared using the contour metrics Dice Similarity Coefficient (DSC), surface-DSC, Hausdorff-distance (HD95%), and accumulated dose-volume histograms (DVHs) analyzed via intraclass correlation coefficient (ICC) and clinical dosimetric criteria (CDC). ResultsFor the GS, median DDA errors ranged from 0.0 to 2.8 Gy across contours and implementations. DIR of clinical cases resulted in DSC > 0.8 for up to 81.3% of contours and a variability of surface-DSC values depending on the implementation. Maximum HD95%=73.3 mm was found for duodenum in the liver case. Although DVH ICC > 0.90 was found after DDA for all but two contours, relevant absolute CDC differences were observed in clinical cases: Prostate I/II showed maximum differences in bladder V28Gy (10.2/7.6%), while for cervix, liver, and lymph node the highest differences were found for rectum D2cm3 (2.8 Gy), duodenum Dmax (7.1 Gy), and rectum D0.5cm3 (4.6 Gy). ConclusionOverall, high agreement was found between the different DIR and DDA implementations. Case- and algorithm-dependent differences were observed, leading to potentially clinically relevant results. Larger studies are needed to define future DDA-guidelines.

Teaching-Track Economists in Canada, the United Kingdom, and the United States

For Canada, the United Kingdom, and the United States, we illuminate the landscape for a relatively new and evolving role: full-time, teaching-track economists who work in the same departments as research-track economists, but with a greater emphasis on te aching. We use in-depth interviews and a large-scale survey. We employ a mixed-methods approach. A cohesive, cross-country, multi-institution comparison enables learning from a variety of contexts. Our findings inform decision-making processes, initiate co nversations among multiple constituents, generate ideas, raise salient questions, and identify relative strengths and weaknesses of different teaching-track models.

Comparing physical therapy students' attitudes and beliefs regarding chronic low back pain and knee osteoarthritis: an international multi-institutional comparison between 2013 and 2020 academic years

BackgroundIn 2013, physical therapy students demonstrated low guideline-adherent recommendations regarding chronic low back pain (CLBP) for spinal pathology, activity, and work. ObjectivesTo assess the differences in physical therapy students’ attitudes, beliefs, and adherence to guideline recommendations regarding CLBP and knee osteoarthritis between 2013 and 2020. MethodsIn 2013 and 2020, second and fourth-year physical therapy students were recruited from 6 Belgian and 2 Dutch institutions. Attitudes and beliefs regarding CLBP and knee OA were evaluated using the Pain Attitudes and Beliefs Scale for Physiotherapists (PABS-PT), the Health Care Providers’ Pain and Impairment Relationship Scale (HC-PAIRS), and a questionnaire regarding therapeutic exercise and knee osteoarthritis. A clinical vignette was used to measure guideline-adherent recommendations regarding spinal pathology, activity, and work. ResultsIn 2013, 927 second-year and 695 fourth-year students; in 2020, 695 second-year and 489 fourth-year students; were recruited to participate in the study. Compared to 2013, students had less biomedical and stronger biopsychosocial attitudes and beliefs regarding CLBP, more guideline-adherent recommendations for activity, and more biopsychosocial beliefs regarding the benefits of exercise for patients with knee osteoarthritis in both the second and fourth year. Only fourth-year students in 2020 scored significantly better on HC-PAIRS and guideline-adherent recommendation relating to spinal pathology. No differences were found regarding work recommendations. ConclusionsBetween 2013 and 2020, physical therapy students made a positive shift towards a more biopsychosocial approach to CLBP and knee osteoarthritis management. Guideline-adherent recommendations for CLBP concerning activity improved, however, concerning work and spinal pathology, it remained low.

AI-based classification of three common malignant tumors in neuro-oncology: A multi-institutional comparison of machine learning and deep learning methods

PurposeTo determine if machine learning (ML) or deep learning (DL) pipelines perform better in AI-based three-class classification of glioblastoma (GBM), intracranial metastatic disease (IMD) and primary CNS lymphoma (PCNSL). MethodologyRetrospective analysis included 502 cases for training (208 GBM, 67 PCNSL and 227 IMD), with external validation on 86 cases (27:27:32). Multiparametric MRI images (T1W, T2W, FLAIR, DWI and T1-CE) were co-registered, resampled, denoised and intensity normalized, followed by semiautomatic 3D segmentation of the enhancing tumor (ET) and peritumoral region (PTR). Model performance was assessed using several ML pipelines and 3D-convolutional neural networks (3D-CNN) using sequence specific masks, as well as combination of masks. All pipelines were trained and evaluated with 5-fold nested cross-validation on internal data followed by external validation using multi-class AUC. ResultsTwo ML models achieved similar performance on test set, one using T2-ET and T2-PTR masks (AUC: 0.885, 95% CI: [0.816, 0.935] and another using T1-CE-ET and FLAIR-PTR mask (AUC: 0.878, CI: [0.804, 0.930]). The best performing DL models achieved an AUC of 0.854, (CI [0.774, 0.914]) on external data using T1-CE-ET and T2-PTR masks, followed by model derived from T1-CE-ET, ADC-ET and FLAIR-PTR masks (AUC: 0.851, CI [0.772, 0.909]). ConclusionBoth ML and DL derived pipelines achieved similar performance. T1-CE mask was used in three of the top four overall models. Additionally, all four models had some mask derived from PTR, either T2WI or FLAIR.

A multi-institutional comparison of acceptance testing data for a 0.35 T MRI scanner

Objective. To present and quantify the variability in the acceptance testing data for the imaging component of the 0.35 T magnetic resonance-linear accelerator (MR-linac). Approach. The current acceptance testing protocol by the MR-linac vendor was described along with the equipment and scanner parameters utilized throughout the process. The Bo field homogeneity, SNR/uniformity of the combined and individual receiver coils, American College of Radiology (ACR) image quality testing, and spatial integrity of the imaging data were collected from twelve different institutions. The variability in the results was accentuated and the ramifications of the results were discussed in the context of MR-guided radiation therapy. Main Results. The Bo field homogeneity was found to have a large gantry dependence with the median values being <4 ppm for all gantry angles. The SNR and uniformity were found to be well above the vendor-specified thresholds with a relatively small institutional-dependence. All institutions passed the ACR image uniformity tests. The largest institutional variability was noted to be for the slice positional accuracy test. The spatial fidelity was calculated to be <1.0 and <2.1 mm within a 100 and a 175 mm radius from the isocenter. Significance. The results from this study can be used to set the tolerances and formal guidelines for MR-linacs imaging quality assurance. Additionally, the multi-institutional data reported in this work will aid in future MR-linac acceptance and commissioning.

Incorporation of Comprehensive Examinations for a Time-Efficient Remediation Method.

Remediation in medical school should be a time-limited, and highly structured process that addresses student deficiencies and allows them to prove content competency before progressing in the curriculum. In this study, we analyze the use of a comprehensive end-of semester final examination in the remediation process for pre-clinical students at Kirk Kerkorian School of Medicine (KSOM). Faculty time utilized is analyzed and compared with the previously employed remediation process. Administered to all students at the end of each semester is a comprehensive examination consisting of a sufficient number of faculty-selected questions relating to each organ system covered with a 75% passing threshold. A student must also demonstrate competency of any failed system examination content to remediate successfully. The performance of those who did not exhibit competency was analyzed to identify areas of deficiency then an individualized exam would then be administered. The total remediation time spent by faculties and students was then analyzed. KSOM Class of 2024 results showed that faculty were able to yield significant savings in time spent on remediation. Faculty spent 45 total remediation hours for the Class of 2024, compared to 400 hours remediating using the paper-based assignment method for the Class of 2021. With the transition to comprehensive end-of-semester final examinations, a total of 355 hours were saved. Furthermore, faculty used an average 1.07 hours/student with end-of-semester comprehensive examinations. The saved time allows faculty to work on improving the overall curriculum for all students rather than focusing on a limited number of students. Utilizing comprehensive end-of-semester final examinations notably decreased the amount of faculty time spent per semester on remediation. Further evaluation is required to evaluate long-term effectiveness on content competency and would further be strengthened by a multi-institutional comparison.

Multi-Institutional Comparison of Ablative Radiation Therapy in 5 Versus 15-25 Fractions for Locally Advanced Pancreatic Cancer

<h3>Purpose/Objective(s)</h3> Ablative RT doses ∼100Gy BED₁₀ are associated with improved overall survival (OS) in patients with locally advanced unresectable pancreatic cancer (LAPC), but the optimal fractionation scheme remains unknown. <h3>Materials/Methods</h3> We performed a retrospective analysis of consecutive LAPC patients treated at 2 high-volume institutions with either 50 Gy in 5 fractions using a 0.35T MR Linac and online adaptive replanning between 2018-2021 or 67.5-75 Gy in 15-25 fractions using CBCT guidance and selective offline adaptive replanning between 2016-2019. All were treated with breath hold or gating. Elective nodal coverage was used in 94%. Clinical characteristics between the groups were compared using Fisher's exact test. Freedom from local progression (FFLP) by RECIST and OS were estimated from time of RT with the Kaplan-Meier method. Log-rank test and Cox proportional hazards regression model were used for univariate (UVA) and multivariate (MVA) analyses. <h3>Results</h3> 183 patients were evaluated including 62 (34%) treated with 50 Gy in 5 fractions, 23 (123%) treated with 67.5 Gy in 15 fractions, and 98 (54%) treated with 75 Gy in 25 fractions. Median age was 67 years (range 35 to 91), 53% were male, 72% had a head tumor location, 81% were T3/4 with a median tumor size of 3.8 cm (range 1.4-7.4 cm) and 38% were lymph node positive. Patients receiving 5 fractions were more likely to be N0 than patients receiving 15-25 fractions (69.3% vs 44.6%, p=0.0219), and there were no other clinical differences between the groups. 98% received induction chemotherapy for a median of 3.9 months (FOLFIRINOX 61%, Gemcitabine/Nab-paclitaxel 29%, other 10%). Median follow-up was 38 months. Median FFLP and OS were 31 and 18 months, with 2-yr FFLP and 2-yr OS of 62.9% (95%CI 47.9 – 69.3%) and 36.2% (26.0 – 40.9%), respectively. There were no significant differences in FFLP (HR= 1.493, 95%CI 0.8030 – 2.775, p=0.1598) or OS (HR=1.321, 95%CI 0.8835 – 1.974, p=0.1580) between patients receiving 5 vs 15-25 fractions, respectively, on UVA. Likewise, after adjusting for T stage, nodal status, tumor size, chemotherapy type and duration, there were no significant differences in OS between the groups on MVA (HR=1.234, 95%CI 0.8151 – 1.833, p=0.3070). The rate of grade 3+ GI bleeding was 4.8% and 8% (p=0.5476) in patients receiving 5 vs 15-25 fractions, respectively. <h3>Conclusion</h3> In appropriately selected LAPC patients, ablative RT (BED₁₀ ∼100 Gy) in 5 fractions delivered with MR guidance and online adaptive replanning or 15-25 fractions delivered with CT guidance and selective offline adaptive replanning both appear to achieve excellent efficacy and minimal severe toxicity. Choice of fractionation scheme should be based on anatomical considerations and available technology.

Multi-Institutional Comparison of SC-TNT and LC-TNT for Rectal Cancer Non-Operative Management

Recent data support the use of total neoadjuvant therapy (TNT) for treatment of locally advanced rectal cancer (LARC), although the optimal TNT regimen and therapy sequence is unclear for non-operative management (NOM). We performed a multi-institutional comparison of short-course radiation (SCRT) followed by consolidation chemotherapy (SC-TNT) versus long-course chemoradiation (CRT) preceded by induction chemotherapy (LC-TNT), after adoption of NOM at both institutions.The records of 187 patients with cT2-4N0-2 rectal cancer treated between 2016-2020 with TNT at two academic institutions were reviewed under an IRB-approved protocol. The SC-TNT cohort (institution 1) included 85 patients treated with SCRT (25-30 Gy in 5 fx) followed by FOLFOX/CAPOX (n = 82) or capecitabine (n = 3). The LC-TNT cohort (institution 2) included 102 patients treated with FOLFOX/CAPOX followed by CRT (45-56 Gy at 1.8-2 Gy/fx) with concurrent fluoropyrimidine-based chemotherapy. Patients with a clinical complete response (cCR) were offered NOM. The rates of cCR were compared between SC- and LC-TNT. Disease-free survival (DFS) was compared using the log-rank test. To account for any differences in NOM selection between institutions, local-only tumor regrowth was censored from DFS if salvaged with R0 resection, and the overall complete response (CR) rate, defined as cCR + pCR rate for patients undergoing surgery, was assessed. Multivariate analysis (MVA) was performed with logistic and Cox regression to determine factors associated with CR and DFS, respectively.The median age at diagnosis was 60 and 54 years for SC-TNT and LC-TNT cohorts, respectively (P = 0.002). All other characteristics including performance status, tumor location, and clinical stage were balanced. The median duration of neoadjuvant FOLFOX/CAPOX chemotherapy was 105 vs 98 days for the SC-TNT and LC-TNT cohorts, respectively (P = 0.001). The median follow-up was 27 months. The cCR rate was higher in the SC-TNT cohort (44/85, 52.8% vs 21/102, 20.6%, P < 0.001), with a trend for improved CR rate for SC-TNT (54.1% vs 40.2%, P = 0.057). On MVA, use of SC-TNT was associated with improved CR (HR = 2.24, 95% CI: 1.13-4.45, P = 0.021). Among patients undergoing NOM, 33/39 patients (84.6%) in the SC-TNT group and 10/17 patients (58.8%) in the LC-TNT group (P = 0.27) were free from local recurrence at 1 year. Two-year DFS was 93.4% and 95.4% for the SC-TNT and LC-TNT cohorts with improved DFS on log-rank test for LC-TNT (P = 0.023), but no DFS difference on MVA between SC-TNT and LC-TNT (HR = 2.29, 95% CI: 0.8-6.51, P = 0.121).SC-TNT demonstrated a greater rate of cCR compared to LC-TNT, without DFS difference on MVA. Although future studies are warranted to compare SC-TNT with a CRT and consolidative chemotherapy TNT approach, our data support SC-TNT as a suitable regimen for LARC NOM.

Multi-institutional Comparison of Intensity Modulated Photon Versus Proton Radiation Therapy in the Management of Squamous Cell Carcinoma of the Anus

PurposeConcurrent chemoradiation therapy is a curative treatment for squamous cell carcinoma of the anus, but patients can suffer from significant treatment-related toxicities. This study was undertaken to determine whether intensity modulated proton therapy (IMPT) is associated with less acute toxicity than intensity modulated radiation therapy (IMRT) using photons. Materials and MethodsWe performed a multi-institutional retrospective study comparing toxicity and oncologic outcomes of IMRT versus IMPT. Patients with stage I-IV (for positive infrarenal para-aortic or common iliac nodes only) squamous cell carcinoma of the anus, as defined by the American Joint Committee on Cancer's AJCC Staging Manual, eighth edition, were included. Patients with nonsquamous histology or mixed IMPT and IMRT treatment courses were excluded. Acute nonhematologic toxicities, per the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE), version 4, were recorded prospectively at all sites. Acute and late toxicities, dose metrics, and oncologic outcomes were compared between IMRT and IMPT using univariable and multivariable statistical methods. To improve the robustness of our analysis, we also analyzed the data using propensity score weighting methods. ResultsA total of 208 patients were treated with either IMPT (58 patients) or IMRT (150 patients). Of the 208 total patients, 13% had stage I disease, 36% stage II, 50% stage III, and 1% stage IV. IMPT reduced the volume of normal tissue receiving low-dose radiation but not high-dose radiation to bladder and bowel. There was no significant difference between treatment groups in overall grade 3 or greater acute toxicity (IMRT, 68%; IMPT, 67%; P = .96) or 2-year overall grade 3 or greater late toxicity (IMRT, 3.5%; IMPT, 1.8%; P = .88). There was no significant difference in 2-year progression-free survival (hazard ratio, 0.8; 95% CI, 0.3-2.0). ConclusionsDespite reducing the volume of normal tissue receiving low-dose radiation, IMPT was not associated with decreased grade 3 or greater acute toxicity as measured by CTCAE. Additional follow-up is needed to assess whether important differences arise in late toxicities and if further prospective evaluation is warranted.

Chemotherapy Versus Chemotherapy Plus Chemoradiation as Neoadjuvant Therapy for Resectable Gastric Adenocarcinoma: A Multi-institutional Analysis.

We compare neoadjuvant chemotherapy (CT) to neoadjuvant chemotherapy plus chemoradiation (CRT) for patients with gastric adenocarcinoma (GA). The optimal neoadjuvant therapy regimen for resectable GA is not defined. Utilizing data from 2 high-volume cancer centers, we analyzed patients who underwent surgery for localized GA from 1/1/2000-12/31/2017. Standard CT regimens were used according to treatment period. We compared propensity matched cohorts based on age, sex, race, histology, and clinical stage. Four-hundred five patients (age 62 ± 12 year, 58% male, 56% White) were analyzed. 231 (57%) received CRT and 174 (43%) received CT. Groups differed based on histopathologic characteristics including preoperative stage (p = 0.013). To control for these differences, propensity matched cohorts of 113 CT and 113 CRT patients were compared. CRT had similar frequencies of microscopically negative resections to CT (93% vs 91%, p = 0.81), but higher rates of complete pathologic response (15% vs 4%, p = 0.003) and lower pathologic stage (p = 0.002). Completion of intended perioperative therapy occurred in 63% of CT and 91% of CRT patients (p < 0.001). Median DFS was 45mo (95%CI: 20-70) in the CT group and 113mo (95%CI: 75-151) in the CRT group (p = 0.018). Median OS was 53mo (95%CI: 30-77) versus 120mo (95%CI: 101-138); p = 0.015. In this multi-institutional comparison of neoadjuvant CT and CRT for resectable GA, CRT is associated with higher rates of completed perioperative therapy, higher rates of complete pathologic response, lower pathologic stage, and improved survival.Level of Evidence: Level III.

P1001 - Monoprophylaxis with cephalosporins for transrectal prostate biopsy after the fluoroquinolone-era: A multi-institutional comparison of infectious complications

P1001 - Monoprophylaxis with cephalosporins for transrectal prostate biopsy after the fluoroquinolone-era: A multi-institutional comparison of infectious complications

18F]FDG uptake of the normal spinal cord in PET/MR imaging: comparison with PET/CT imaging

BackgroundThe lack of visualization of the spinal cord hinders the evaluation of [18F]Fluoro-deoxy-glucose (FDG) uptake of the spinal cord in PET/CT. By exploiting the capability of MRI to precisely outline the spinal cord, we performed a retrospective study aimed to define normal pattern of spinal cord [18F]FDG uptake in PET/MRI.MethodsForty-one patients with lymphoma without clinical or MRI signs of spinal cord or bone marrow involvement underwent simultaneous PET and MRI acquisition using Siemens Biograph mMR after injection of 3.5 MBq/kg body weight of [18F]FDG for staging purposes. Using a custom-made software, we placed ROIs of 3 and 9 mm in diameter in the spinal cord, lumbar CSF, and vertebral marrow that were identified on MRI at 5 levels (C2, C5, T6, T12, and L3). The SUVmax, SUVmean, and the SUVmax and SUVmean normalized (NSUVmax and NSUVmean) to the liver were measured. For comparison, the same ROIs were placed in PET-CT images obtained immediately before the PET-MRI acquisition following the same tracer injection.ResultsOn PET/MRI using the 3 mm ROI, the following average (all level excluding L3) spinal cord median (1st and 3rd quartile) values were measured: SUVmean, 1.68 (1.39 and 1.83); SUVmax, 1.92 (1.60 and 2.14); NSUVmean, 1.18 (0.93 and 1.36); and NSUVmax, 1.27 (1.01 and 1.33). Using the 9 mm ROI, the corresponding values were SUVmean, 1.41 (1.25–1.55); SUVmax, 2.41 (2.08 and 2.61); NSUVmean, 0.93 (0.79 and 1.04); and NSUVmax, 1.28 (1.02 and 1.39). Using the 3 mm ROI, the highest values of PET-MRI SUVmax, SUVmean, NSUVmax, and NSUVmean were consistently observed at C5 and the lowest at T6. Using a 9 mm ROI, the highest values were consistently observed at C5 and the lowest at T12 or T6. The spinal cord [18F]FDG-uptake values correlated with the bone marrow uptake at the same level, especially in case of NSUVmax. Comparison with PET-CT data revealed that the average SUVmax and SUVmean of the spinal cord were similar in PET-MRI and PET-CT. However, the average NSUVmax and NSUVmean of the spinal cord were higher (range 21–47%) in PET-MRI than in PET-CT.ConclusionsUsing a whole-body protocol, we defined the maximum and mean [18F]FDG uptake of the normal spinal cord in PET/MRI. While the observed values show the expected longitudinal distribution, they appear to be higher than those measured in PET/CT. Normalization of the SUVmax and SUVmean of the spinal cord to the liver radiotracer uptake could help in multi-institutional comparisons and studies.

A multi-institution study: comparison of the heating patterns of five different MR-guided deep hyperthermia systems using an anthropomorphic phantom

Introduction Within the hyperthermia community, consensus exists that clinical outcome of the treatment radiotherapy and/or chemotherapy plus hyperthermia (i.e. elevating tumor temperature to 40 − 44 °C) is related to the applied thermal dose; hence, treatment quality is crucial for the success of prospective multi-institution clinical trials. Currently, applicator quality assurance (QA) measurements are implemented independently at each institution using basic cylindrical phantoms. A multi-institution comparison of heating quality using magnetic resonance thermometry (MRT) and anatomical representative anthropomorphic phantoms provides a unique opportunity to obtain novel QA insights to facilitate multi-institution trial evaluation. Objective Perform a systematic QA procedure to compare the performance of MR-compatible hyperthermia systems in five institutions. Methods and materials Anthropomorphic phantoms, including pelvic and spinal bones, were produced. Clinically relevant power of 600 watts was applied for ∼12 min to allow for 8 sequential MR-scans. The 3D-heating distribution, steering capabilities, and presence of off-target heating were analyzed. Results The evaluated devices show comparable heating profiles for centric and eccentric targets. The differences observed in the 3D-heating profiles are the result of variations in the exact phantom positioning and applicator characteristics, whereby positioning of the phantom followed current ESHO-QA guidelines. Conclusion Anthropomorphic phantoms were used to perform QA-measurements of MR-guided hyperthermia systems operating in MR-scanners of different brands. Comparable heating profiles are shown for the five evaluated institutions. Subcentimeter differences in position substantially affected the results when evaluating the heating patterns. Integration of advanced phantoms and precise positioning in QA-guidelines should be evaluated to guarantee the best quality patient care.

A multi institutional comparison of imaging dose and technique protocols for neonatal chest radiography

IntroductionThe focus on paediatric radiation dose reduction supports reevaluation of paediatric imaging protocols. This is particularly important in the neonates where chest radiographs are frequently requested to assess respiratory illness and line placement. This study aims to assess the impact of neonatal chest radiographic protocols on patient dose in four hospitals in different countries. MethodsExposure parameters, collimation, focus to skin distance (FSD) and radiation dose from 200 neonatal chest radiographs were registered prospectively. Inclusion criteria consisted of both premature and full-term neonates weighing between 1000 and 5000 g. Only data from the examinations meeting diagnostic criteria and approved for the clinical use were included. Radiation dose was assessed using dose area product (DAP). ResultsThe lowest DAP value (4.58 mGy cm2) was recorded in the Norwegian hospital, employing a high kVp, low mAs protocol using a DR system. The Canadian hospital recorded the highest DAP (9.48), using lower kVp and higher mAs with a CR system, including the addition of a lateral projection. The difference in the mean DAP, weight, field of view (FOV) and kVp between the hospitals is statistically significant (p < 0.001). ConclusionUse of non-standardised imaging protocols in neonatal chest radiography results in differences in patient dose across hospitals included in the study. Using higher kVp, lower mAs and reducing the number of lateral projections to clinically relevant indications result in a lower DAP measured in the infant sample studied. Further studies to examine image quality based on exposure factors and added filtration are recommended. Implications for practiceReevaluation of paediatric imaging protocols presents an opportunity to reduce patient dose in a population with increased sensitivity to ionising radiation.

Multi-Institutional Comparison of Intensity Modulated Photon Versus Proton Radiotherapy in the Management of Squamous Cell Carcinoma of the Anal Canal

Multi-Institutional Comparison of Intensity Modulated Photon Versus Proton Radiotherapy in the Management of Squamous Cell Carcinoma of the Anal Canal

Multi-institutional evaluation of knowledge-based planning performance of volumetric modulated arc therapy (VMAT) for head and neck cancer

PurposeThe aim of this study was to investigate whether additional manual objectives are necessary for the RapidPlan (RP) with a single optimization. We conducted multi-institutional comparisons of plan quality for head and neck cancer (HNC) using the models created at each institute. MethodsThe ability of RP to produce acceptable plans for dose requirements was evaluated in two types of oropharynx cancers at five institutes in Japan. Volumetric modulated arc therapy plans created without (RP plan) and with additional manual objectives (M-RP plan) were compared in terms of planning target volume (PTV), brainstem, spinal cord and parotid glands in dosimetric parameters. ResultsThere were no major dosimetric PTV differences between RP and M-RP plans. For the brainstem and spinal cord in the RP plans, only 40% and 30% of the plans achieved the dose requirements, while the M-RP plans with upper objective added to volume 0% at all institutes achieved them for 90% of the plans. For the L-parotid gland, there was no difference in the RP and M-RP plans (both were 40%) in achieving the acceptable criteria. For the R-parotid gland, 60% and 80% of the RP and M-RP plans achieved the constraint criteria, and in terms of the achievement rate, the RP plans were relatively high. ConclusionsM-RP plans did not require reoptimization; only an upper objective was needed for the brainstem and spinal cord, while the parotid gland dose was reduced in both RP plans with the auto generated line objectives alone.

Correction to: Differences in Characteristics and Outcome of Patients with Penetrating Injuries in the USA and the Netherlands: A Multi-institutional Comparison.

In the original article Dennis Den Hartog's name was tagged incorrectly. It is correct as reflected here.