WE-B-T-6E-01: Source Modelling and Beam Commissioning for Monte Carlo Treatment Planning

Abstract

Source modeling and beam commissioning are important components of a Monte Carlo based treatment planning system. In this presentation, we will review the current status of Monte Carlo simulations of clinical photon and electron beams and the theories and methodologies used in particle phase space representation and reconstruction for Monte Carlo dose calculation. We will discuss the sensitivity of beam characterization to simulation details, such as beam energy, angle, intensity, and details of the treatment head design. We will review different source models for photon and electron beam characterization and discuss the accuracy and efficiency tradeoffs between full phase space and simplified source models. We will describe the methods and software that have been developed for source modeling and beam commissioning for the clinical implementation of the Monte Carlo method for treatment planning and beam delivery verification. We will present different methods for source parameterization based on simulated phase space data and a standard set of measured beam data including in-air and in-phantom output factors and in-phantom dose distributions. We will discuss problems associated with CT scanning and phantoms that can affect Monte Carlo accuracy. We will describe requirements and procedures for commissioning and acceptance testing of Monte Carlo dose calculation software for radiotherapy treatment planning. Educational Objectives: 1. Introduce the Monte Carlo method for clinical photon and electron beam simulations 2. Review theories and methodologies for phase space representation and reconstruction 3. Present different source models for Monte Carlo dose calculation 4. Describe different methods for source parameterization and beam commissioning 5. Provide requirements and guidelines for the clinical testing of Monte Carlo dose calculation software for radiotherapy treatment planning