Investigation of FLUKA Monte Carlo code to study the influence of degrader and initial proton energy in the Bragg peak position

Abstract Introduction: In recent times, numerous leading global societies have endeavored to advance proton therapy technology with the aim of making it universally accessible. The goal is to offer proton therapy to all cancer patients who stand to benefit from it, thereby enhancing their overall quality of life. This shared objective unites radiation oncologists, medical physicists, radiotherapists, and hospital directors worldwide. The introduction of proton therapy systems, coupled with adjustments to the momentum analysis system, holds potential clinical benefits. Material and Methods: The momentum analysis system typically modifies the energy of the clinical proton beam, influencing the shape and position of the Bragg peak. FLUKA, a Monte Carlo-based software, was employed to simulate various beam setups by directing the proton beam into a water phantom. The resulting Bragg peaks were analyzed and compared with those from different setup simulations. Results: The findings indicate that the Bragg peak undergoes changes in a proton therapy system, both with and without a modulator, across all potential tumor depths. The results demonstrate that the position of the Bragg peak can vary from Z = 31.4 cm for deep tumors such as prostate to Z = 2.6 cm for spinal axis tumors, solely by adjusting the modulator depth from ΔZ modulator = 5 to ΔZ modulator = 30 cm for an energy level of 250 MeV, without altering the proton beam energies. Conclusion: The investigation of these results plays a potential dosimetric consequence, especially for clinics interested in acquiring such a proton therapy system for treating and managing tumors at varying depths.