PMID- 37928618 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20231107 IS - 2405-6316 (Electronic) IS - 2405-6316 (Linking) VI - 28 DP - 2023 Oct TI - Prior knowledge based deep learning auto-segmentation in magnetic resonance imaging-guided radiotherapy of prostate cancer. PG - 100498 LID - 10.1016/j.phro.2023.100498 [doi] LID - 100498 AB - BACKGROUND AND PURPOSE: Automation is desirable for organ segmentation in radiotherapy. This study compared deep learning methods for auto-segmentation of organs-at-risk (OARs) and clinical target volume (CTV) in prostate cancer patients undergoing fractionated magnetic resonance (MR)-guided adaptive radiation therapy. Models predicting dense displacement fields (DDFMs) between planning and fraction images were compared to patient-specific (PSM) and baseline (BM) segmentation models. MATERIALS AND METHODS: A dataset of 92 patients with planning and fraction MR images (MRIs) from two institutions were used. DDFMs were trained to predict dense displacement fields (DDFs) between the planning and fraction images, which were subsequently used to propagate the planning contours of the bladder, rectum, and CTV to the daily MRI. The training was performed either with true planning-fraction image pairs or with planning images and their counterparts deformed by known DDFs. The BMs were trained on 53 planning images, while to generate PSMs, the BMs were fine-tuned using the planning image of a given single patient. The evaluation included Dice similarity coefficient (DSC), the average (HD(avg)) and the 95th percentile (HD(95)) Hausdorff distance (HD). RESULTS: The DDFMs with DSCs for bladder/rectum of 0.76/0.76 performed worse than PSMs (0.91/0.90) and BMs (0.89/0.88). The same trend was observed for HDs. For CTV, DDFM and PSM performed similarly yielding DSCs of 0.87 and 0.84, respectively. CONCLUSIONS: DDFMs were found suitable for CTV delineation after rigid alignment. However, for OARs they were outperformed by PSMs, as they predicted only limited deformations even in the presence of substantial anatomical changes. CI - (c) 2023 The Author(s). FAU - Kawula, Maria AU - Kawula M AD - Department of Radiation Oncology, LMU University Hospital, LMU Munich, Munich, Germany. FAU - Vagni, Marica AU - Vagni M AD - Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, Italy. FAU - Cusumano, Davide AU - Cusumano D AD - Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, Italy. AD - Mater Olbia Hospital, Olbia (SS), Italy. FAU - Boldrini, Luca AU - Boldrini L AD - Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, Italy. FAU - Placidi, Lorenzo AU - Placidi L AD - Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS, Rome, Italy. FAU - Corradini, Stefanie AU - Corradini S AD - Department of Radiation Oncology, LMU University Hospital, LMU Munich, Munich, Germany. FAU - Belka, Claus AU - Belka C AD - Department of Radiation Oncology, LMU University Hospital, LMU Munich, Munich, Germany. AD - German Cancer Consortium (DKTK), Partner Site Munich, A Partnership Between DKFZ and LMU University Hospital Munich, Germany. AD - Bavarian Cancer Research Center (BZKF), Munich, Germany. FAU - Landry, Guillaume AU - Landry G AD - Department of Radiation Oncology, LMU University Hospital, LMU Munich, Munich, Germany. FAU - Kurz, Christopher AU - Kurz C AD - Department of Radiation Oncology, LMU University Hospital, LMU Munich, Munich, Germany. LA - eng PT - Journal Article DEP - 20231010 PL - Netherlands TA - Phys Imaging Radiat Oncol JT - Physics and imaging in radiation oncology JID - 101704276 PMC - PMC10624570 OTO - NOTNLM OT - Auto-segmentation OT - Deep learning OT - MR-Linac OT - MRgRT OT - Patient-specific models OT - Prostate cancer OT - Spatial transformer layer COIS- The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The Department of Radiation Oncology of the University Hospital of LMU Munich has a research agreement with ViewRay. ViewRay did not fund this study and was not involved and had no influence on the study design, the collection or analysis of data, or on the writing of the manuscript. EDAT- 2023/11/06 06:42 MHDA- 2023/11/06 06:43 PMCR- 2023/10/10 CRDT- 2023/11/06 04:37 PHST- 2023/05/30 00:00 [received] PHST- 2023/10/03 00:00 [revised] PHST- 2023/10/04 00:00 [accepted] PHST- 2023/11/06 06:43 [medline] PHST- 2023/11/06 06:42 [pubmed] PHST- 2023/11/06 04:37 [entrez] PHST- 2023/10/10 00:00 [pmc-release] AID - S2405-6316(23)00089-1 [pii] AID - 100498 [pii] AID - 10.1016/j.phro.2023.100498 [doi] PST - epublish SO - Phys Imaging Radiat Oncol. 2023 Oct 10;28:100498. doi: 10.1016/j.phro.2023.100498. eCollection 2023 Oct.