Configuration of the PRIMO software to simulate intensity modulated radiation therapy through dynalog file

Abstract

Introduction Varian DynaLog files contain information on the Multi Leaf Collimator (MLC) actual configuration, and gantry and collimator angles during Intensity Modulated Radiation Therapy (IMRT). The Monte Carlo (MC) simulation of an actual IMRT procedure allows studying the dosimetric effect of possible mismatches between planned and actual delivery. The PRIMO software is a MC software targeted to External Radiotherapy environment. Nevertheless, IMRT is not part of the implemented options. Purpose To configure PRIMO to simulate an actual IMRT procedure by DynaLog files manipulation. Materials and methods A Varian 2300CD LINAC associated to a 120HD MLC was simulated. Static simulations were primarily performed to verify the LINAC and MLC models against experimental data. A dynamic irradiation with MLC modulation was split into a sequence of static segments. PRIMO was configured by introducing the DynaLog files information and the procedure was simulated on a solid water phantom. Gafchromic films were used to measure actual dose distribution and to compare it with the simulations through a 2D Gamma analysis. Results More than 95% of Gamma points Conclusion A workflow was developed to configure PRIMO to simulate IMRT through the direct introduction of DynaLog files. These results represent an initial study towards a clinically useful implementation of IMRT simulation using PRIMO. Disclosure The authors have no relevant financial or nonfinancial relationships to disclose.