Commissioning and validation of TOPAS beam model for IBA Proteus-ONE at UFHPTI

Abstract Proteus-ONE (P-ONE) is a novel compact single-room system developed by Ion Beam Application (IBA, Belgium) for proton therapy. The objective of this research was to commission and validate Monte Carlo (MC) beam model for P-ONE using the TOol of PArticle Simulation (TOPAS) Monte Carlo software package. Thirty-three energies were determined within P-ONE energy range (70-227 MeV) to measure integral depth dose (IDD), absolute dose and in-air lateral profiles. The beam model was established by matching TOPAS simulation with measurement for each energy. To validate the accuracy of obtained TOPAS beam model, we compared TOPAS simulation with measurement under various scenarios, including different spread-out Bragg peaks, lateral dose curves and gamma passing rates (GPRs) for 3x3x3 cm3, 5x5x5 cm3, and 7x7x7 cm3 uniform target in a water phantom. Good agreement was observed and GPRs reached 100% among all measurement planes with 3%/3mm criteria and above 95% with 2%/2mm criteria. Three patient cases including head and neck, breast and prostate were used for gamma analysis and at least GPRs of 99.8% and 95.4% were reached among all measurement planes with the criteria of 3%/3mm and 2%/2m, respectively. The results indicated the accuracy and reliability of the obtained TOPAS beam model which has the potential to serve clinical or research purposes.