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

• DOI: 10.1016/j.phro.2024.100588
• Publication Date: 2024-05-17T10:44:22Z
• Authors: Martina Murr; Uffe Bernchou; Edyta Bubula-Rehm; Mark Ruschin; Parisa Sadeghi; Peter Voet; Jeff D Winter; Jinzhong Yang; Eyesha Younus; Cornel Zachiu; Yao Zhao; Hualiang Zhong; Daniela Thorwarth
• Keywords: Medical Sciences; Radiation; Bioinformatics; R895-920; 610; Neoplasms. Tumors. Oncology. Including cancer and carcinogens; Biomedical Informatics; Deformable image registration (DIR); Online MR-guided radiotherapy (MRgRT); Medical physics. Medical radiology. Nuclear medicine; 0302 clinical medicine; Oncology; Multi-institutional analysis; Radiology Nuclear Medicine and imaging; Medical Specialties; Medicine and Health Sciences; Original Research Article; RC254-282; Deformable dose accumulation (DDA)

Application 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.One 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).For 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).Overall, 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.