Practice-based training strategy for therapist-driven prostate MR-Linac adaptive radiotherapy

• Published in: Technical innovations & patient support in radiation oncology Vol. 27; p. 100212
• Main Authors: Li, Winnie, Padayachee, Jerusha, Navarro, Inmaculada, Winter, Jeff, Dang, Jennifer, Raman, Srinivas, Kong, Vickie, Berlin, Alejandro, Catton, Charles, Glicksman, Rachel, Malkov, Victor, McPartlin, Andrew, Kataki, Kaushik, Lindsay, Patricia, Chung, Peter
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01.09.2023; Elsevier
• Subjects: Adaptive radiation therapy; MR-Linac; Prostate; Research article; Therapist-driven workflow; MR-Linac; Prostate; Adaptive radiation therapy; Therapist-driven workflow
• ISSN: 2405-6324; 2405-6324
• DOI: 10.1016/j.tipsro.2023.100212

•Training strategy developed to enable therapist-driven prostate MR-Linac treatment.•A three-phase training strategy was implemented and evaluated in this study.•Strategy applicable to other treatment sites for therapy-driven workflows. To develop a practice-based training strategy to transition from radiation oncologist to therapist-driven prostate MR-Linac adaptive radiotherapy. In phase 1, 7 therapists independently contoured the prostate and organs-at-risk on T2-weighted MR images from 11 previously treated MR-Linac prostate patients. Contours were evaluated quantitatively (i.e. Dice similarity coefficient [DSC] calculated against oncologist generated online contours) and qualitatively (i.e. oncologist using a 5-point Likert scale; a score ≥ 4 was deemed a pass, a 90% pass rate was required to proceed to the next phase). Phase 2 consisted of supervised online workflow with therapists required no intervention from the oncologist on 10 total cases to advance. Phase 3 involved unsupervised therapist-driven workflow, with offline support from oncologists prior to the next fraction. In phase 1, the mean DSC was 0.92 (range 0.85–0.97), and mean Likert score was 3.7 for the prostate. Five therapists did not attain a pass rate (3–5 cases with prostate contour score < 4), underwent follow-up one-on-one review, and performed contours on a further training set (n = 5). Each participant completed a median of 12 (range 10–13) cases in phase 2; of 82 cases, minor direction were required from the oncologist on 5 regarding target contouring. Radiation oncologists reviewed 179 treatment fractions in phase 3, and deemed 5 cases acceptable but with suggestions for next fraction; all other cases were accepted without suggestions. A training stepwise program was developed and successfully implemented to enable a therapist-driven workflow for online prostate MR-Linac adaptive radiotherapy.