Collimator design for spatially-fractionated proton beams for radiobiology research

摘要: Preclinical and translational research is an imperative to improve the efficacy of proton radiotherapy. We present a feasible practical method produce spatially-modulated beams for cellular small animal clinical facilities. The University Washington (UW) 50.5 MeV beamline hosting brass collimation system was modeled using Monte Carlo simulations. This collimator consisted array 2 cm long slits cover area 2  ×  2 cm(2). To evaluate design effects on dose rate, valley peak-to-valley ratios (PVDR) following parameters were varied; slit width (0.1-1.0 mm), peak center-to-center distance (1-3 mm), thickness (1-7 cm) location along beam axis. Several combinations widths 1 mm spacing achieved uniform at Bragg while maintaining spatial modulation entrance. A more detailed analysis carried out case 0.3 mm, 1 mm, 5 cm with flush against water phantom. rate 5 mm depth dropped relative open field by factor 12 produced PVDR 10.1. Technical realization mini-beams radiobiology demonstrated be feasible. It possible obtain reasonable shallower depths near While important has strong influence entrance region PVDRs rate. These findings are being used manufacture installation UW cyclotron nozzle. will enable comparative studies radiobiological x-rays beams.