Verifcation of dose calculations in a heterogeneous phantom using PRIMO

Abstract

Treatment planning systems (TPSs) are routinely used in radiotherapy to calculate the monitor units (MU) required to deposit a certain amount of energy per unit mass in the patient and the dose distribution in it due to their high calculation speed. To reduce calculation time, TPSs adopt several approximations which are optimized for low atomic number materials such as those found in the human body. These approximations may lead to substantial deviations between calculated and measured dose in the presence of heterogeneities. In the present TFG we employ Monte Carlo simulations to study these discrepancies and verify the TPS calculations. The program used is PRIMO, which is based on the penelope code system.