Evaluation of a commercial electron Monte Carlo dose calculation algorithm for electron beams

The aim of Radiotherapy is to maximize tumour control and minimize normal tissue complications. For this reason in external beam radiotherapy are used computerized Treatment Planning Systems (TPSs) to generate beam shapes and dose distributions that conform as closely as possible to the target volume in terms of adequate dose to the tumor and minimum possible dose to normal tissue. Dose calculation algorithms are the most critical software component in a TPS. These modules are responsible for the correct representation of dose in the patient, and may be linked to beam time or monitor unit (MU) calculations. The Monte Carlo (MC) technique is potentially the most accurate method for solving the coupled electron-photon transport problem. However, because of the stochastic nature of MC calculation and inevitable variations in measurements, it is necessary to verify the agreement between calculation and measurement data. In this study, electron Monte Carlo (eMC) calculated and measured dose distributions are compared. The comparison is made both along the electron beam direction and perpendicular to it, for electron energy and applicator combination, and using measurement data from two Varian Clinac DHX accelerators.