Applicability and usage of dose mapping/accumulation in radiotherapy
Date:
Dose mapping/accumulation (DMA) has been a topic in radiotherapy (RT) for years but has not yet found its widespread way into clinical RT routine. During the ESTRO Physics workshop 2021 on ‘commissioning and quality assurance of deformable image registration (DIR) for current and future RT applications’, we built a working group on DMA from which we present the results of our discussions in this symposium based on the article [1]. This article aims to shed light on the current DMA situation in RT and highlight the issues that hinder its conscious integration into clinical RT routine. As a first outcome of our discussions, we present a scheme (cf. Figure 1) where representative RT use cases are positioned, considering expected anatomical variations and the impact of dose mapping uncertainties on patient safety, which we have named the DMA landscape (DMAL). This tool is helpful for future reference when DMA applications get closer to clinical day-to-day use. Secondly, we discussed current challenges, lightly touching on first-order effects (related to the impact of DIR uncertainties in dose mapping) and focusing in detail on second-order effects often dismissed in the current literature (such as resampling and interpolation, quality assurance considerations, and radiobiological issues). Finally, we developed recommendations and guidelines for vendors and users. Our main points include: • Striving for context-driven DIR (considering their impact on clinical decisions/judgments) rather than perfect DIR. • Being conscious of the limitations of the implemented DIR algorithm. • Consider when dose mapping (with properly quantified uncertainties) is a better alternative than no mapping.