Interobserver variation of clinical oncologists compared to therapeutic radiographers (RTT) prostate contours on T2 weighted MRI

The implementation of MRI-guided online adaptive radiotherapy has enabled extension of therapeutic radiographers’ roles to include contouring. An offline interobserver variability study compared five radiographers’ and five clinicians’ contours on 10 MRIs acquired on a MR-Linac from 10 patients. All contours were compared to a “gold standard” created from an average of clinicians’ contours. The median (range) DSC of radiographers’ and clinicians’ contours compared to the “gold standard” was 0.91 (0.86–0.96), and 0.93 (0.88–0.97) respectively illustrating non-inferiority of the radiographers’ contours to the clinicians. There was no significant difference in HD, MDA or volume size between the groups.