SU‐E‐J‐145: Validation of An Analytical Model for in Vivo Range Verification Using GATE Monte Carlo Simulation in Proton Therapy

Abstract

Purpose:Predicted PET images on the basis of analytical filtering approach for proton range verification has been successful developed and validated using FLUKA Monte Carlo (MC) codes and phantom measurements. The purpose of the study is to validate the effectiveness of analytical filtering model for proton range verification on GATE/GEANT4 Monte Carlo simulation codes.Methods:In this study, we performed two experiments for validation of predicted β+‐isotope by the analytical model with GATE/GEANT4 simulations. The first experiments to evaluate the accuracy of predicting β+‐yields as a function of irradiated proton energies. In second experiment, we simulate homogeneous phantoms of different materials irradiated by a mono‐energetic pencil‐like proton beam. The results of filtered β+‐yields distributions by the analytical model is compared with those of MC simulated β+‐yields in proximal and distal fall‐off ranges.Results:The results investigate the distribution between filtered β+‐yields and MC simulated β+‐yields distribution in different conditions. First, we found that the analytical filtering can be applied over the whole range of the therapeutic energies. Second, the range difference between filtered β+‐yields and MC simulated β+‐yields at the distal fall‐off region are within 1.5mm for all materials used. The findings validated the usefulness of analytical filtering model on range verification of proton therapy on GATE Monte Carlo simulations. In addition, there is a larger discrepancy between filtered prediction and MC simulated β+‐yields using GATE code, especially in proximal region. This discrepancy might Result from the absence of wellestablished theoretical models for predicting the nuclear interactions.Conclusion:Despite the fact that large discrepancies of the distributions between MC‐simulated and predicted β+‐yields were observed, the study prove the effectiveness of analytical filtering model for proton range verification using GATE Monte Carlo simulation.