In the context of radiosurgery - pros and cons of rescanning as a solution for treating moving targets with scanned particle beams

Abstract

The treatment of mobile targets with scanned particle beams is challenging, and the effects of motion will be especially pronounced in hypo-fractionated treatment regimes due to the lack of statistical smoothing through fractionation and the prolonged delivery times per session. Therefore, motion mitigation techniques will play a major role for radiosurgery approaches. This article concentrates on the motion mitigation technique called rescanning. It alludes the existence of many scanning/rescanning flavors and raises awareness of the importance of an optimized flavor choice. Furthermore, it is discussed that rescanning can compensate for the lack of statistical wash-out, target dose conformity, however, will remain degraded. Therefore, especially in the context of radiosurgery, rescanning should be combined with other motion mitigation techniques like breath hold, gating and/or tracking.

Keywords: Hypo-fractionated treatment; Radiosurgery; Rescanning; Scanned particle beams; Target motion.