Precision radiation oncology
Evaluation of Concordance between Radiation Therapists and Medical Physicists in MR-Guided Online Adaptive Planning
By Birring E, Zhao Y, Lim TY and 8 others.
Abstract
Purpose
Magnetic resonance (MR) -guided online adaptive radiotherapy requires skill in online adaptive treatment planning. The aim of this study was to demonstrate that radiation therapists, with appropriate training, can consistently produce high-quality adaptive plans concordant with those created by medical physicists for treatment on a 1.5 Tesla MR-Linac (MRL).
Methods
We evaluated plans generated by two experienced MRL radiation therapists and two MR-Linac medical physicists using an adapt-to-position (ATP) workflow to treat 10 patients with head and neck cancer; this workflow includes an iso-center shift and plan re-optimization to account for setup discrepancy between simulation and treatment. For each adaptive session, CT-MR images were fused and isocenter translational shifts recorded. Differences among the three roles (Therapist, Physicist 1, Physicist 2) were assessed by repeated-measures analysis of variance (RM-ANOVA) and Bonferroni-corrected post-hoc paired t tests, reported as secondary, exploratory analyses. Agreement on shifts and dosimetric endpoints was quantified with Lin's concordance correlation coefficient (CCC), with bias-corrected and accelerated bootstrap 95% confidence intervals (CIs), as the primary analysis.