Physical Uncertainties in the Planning and Delivery of Light Ion Beam Treatments-2635056A

Light ion beam treatments are becoming more widely used. Safe and optimal treatments may only be achieved when uncertainties are considered at every step of the planning and delivery process. These uncertainties include, but are not limited to, penetration uncertainties due to beam delivery, uncertainties in dose compliance, uncertainties of x-ray computed tomography numbers, absolute and relative linear stopping powers, absolute and relative linear scattering powers, conversion of x-ray computed tomography numbers to relative linear stopping power, lateral alignment uncertainties, and uncertainties due to inter-fractional and intra-fractional anatomical variations. Knowing the source and magnitude of these uncertainties, the planner must optimize the plans to mitigate the effect of these uncertainties as much as possible without making the plan undeliverable. Visualization of dose distributions considering the effects of these uncertainties is an important step in evaluating the safety and effectiveness of the plans. This report by Task Group 202 of the AAPM has endeavored to address each of these topics as a guide to the user of light ion beam treatments.