Preclinical Challenges in Proton Minibeam Radiotherapy: Physics and Biomedical Aspects

Proton minibeam radiotherapy (pMBRT) was explored as a promising approach for better sparing of normal tissue compared to X-ray minibeams, with preclinical experiments in mouse and rat models supporting its potential benefits. The research was still in early stages, particularly regarding the radiobiological mechanisms and optimal application parameters. Glioma, non-small cell lung cancer, and hepatocellular carcinoma were identified as promising targets, with a focus on effects on healthy tissue. Technological challenges in preclinical setups were noted, with a preference for focusing pencil or planar minibeams over collimation due to better dose ratios and rates. A proposed solution involved using a 3 GHz radio-frequency linear accelerator to generate focused proton minibeams, which could enhance preclinical studies and advance precision tumor therapy.