The impact of Monte Carlo dose calculations on treatment outcomes

Abstract

Accurate calculation of dose distributions for radiation therapy has long been a goal of medical physicists. The more advanced current dose calculation algorithms, such as the superposition/convolution method,1–4 can accurately compute dose in most instances. However, the accuracy of currently available dose computation models for planning of radiation treatments is limited,5–10 and in extreme cases, even these advanced methods can result in dose errors of several percent. Discrepancies compared to dose distributions may be clinically significant for some cases. Monte Carlo-based dose calculations can potentially compute dose with an accuracy that surpasses that of conventional algorithms.10 Monte Carlo dose calculation is theoretically limited only by the daily change in patient anatomy (due to patient positioning, motion, or physiological changes), by the uncertainty with which patient materials can be estimated, and by the accuracy of the measured data used to commission the Monte Carlo dose calculation algorithm.