Comparative assessment of passive scattering and active scanning proton therapy techniques using Monte Carlo simulations

Abstract Background: in this study, two proton beam delivery designs, i.e. passive scattering therapy (PSPT) and pencil scanning (PBS), were quantitatively compared terms of dosimetric indices. The GATE Monte Carlo (MC) particle transport code was used to simulate the system; developed simulation engines benchmarked with respect experimental measurements. Method: a water phantom system energy parameters using set depth-dose data range 120–235 MeV. To compare performance PSPT against PBS, multiple including Bragg peak width (BP W 50 ), position, range, peak-to-entrance dose ratio, penumbra (90-10)% , (80-20)% M 95% volume histogram have been analyzed under same conditions. Furthermore, clinical test cases introduced by AAPM TG-119 simulated both modes relevant values obtained from Dose Volume Histogram (DVH) analysis. Results: parametric comparison between techniques revealed that value ratio is considerably higher than PBS factor 8%. In addition, BP_W50, increased 7, 51, 37, 2.7%, respectively corresponding model. simulations showed difference PTV mean are up 1.8% while max organ at risks (OARs) exceeds 50%. Conclusion: results show although design method has slightly ability adjust target volume, but active systems superior painting, lower out-of-field design.