Patient reported outcomes of slow, single arc rotation: Do we need rotating gantries?

IntroductionPatient rotation could greatly simplify radiation therapy delivery, with particularly important ramifications for fixed beam treatment with protons, heavy ions, MRI-Linacs, and low cost Linacs. Patient tolerance is often cited as a barrier to widespread implementation to patient rotation; however, no quantitative data addressing this issue exists. In this study, patient reported experiences of slow, single arc rotation in upright (sitting) and lying orientations are reported. MethodsFifteen patients currently or previously treated for cancer were slowly (2rpm) rotated in upright and lying orientations using an existing medical device. Patients were rotated 360 degrees in 45 degrees increments. Rotation was paused for 30 seconds at each angle to simulate beam delivery. Claustrophobia, anxiety and motion sickness were monitored via validated questionnaires. The Wilcoxon signed rank test was used to test for significant differences in anxiety and motion sickness before, during and after the study. ResultsNo significant differences in anxiety or motion sickness were found between before and after the study, or upright and lying rotation (P>0.05). The median percentage scores for anxiety and motion sickness immediately following the study were both 0. In general, anxiety and motion sickness scores were low throughout the study. All patients except one completed the study. ConclusionsSlow, single arc rotation in upright and lying orientations was well tolerated in this study. These results support the need for further studies into the clinical implementation of patient rotation, which could have a major impact on the practice and cost of radiotherapy.