Implementation of planar proton minibeam radiation therapy using a pencil beam scanning system: A proof of concept study

• DOI: 10.1002/mp.13209
• Publication Date: 2018-09-22T15:09:32Z
• Authors: Ludovic De Marzi; Annalisa Patriarca; Catherine Nauraye; Eric Hierso; Rémi Dendale; Consuelo Guardiola; Yolanda Prezado
• Keywords: Pencil-beam scanning; Pencil (optics)

Proton minibeam radiation therapy (pMBRT) is an innovative approach that combines the advantages of with more precise ballistics protons to further reduce side effects radiation. One main challenges this generation very narrow proton pencil beams adequate dose-rate treat patients within a reasonable treatment time (several minutes) in existing clinical facilities. The aim study was demonstrate feasibility implementing pMBRT by combining beam scanning (PBS) technique use multislit collimators. This proof concept system intended guide upcoming biological experiments.Monte Carlo simulations (TOPAS v3.1.p2) were used design suitable collimator implement planar for conventional settings. Dose distributions (depth-dose curves, lateral profiles, Peak-to-Valley Ratio (PVDR) and dose-rates) different energies assessed means Monte experimental measurements water tank using commercial ionization chambers new p-type silicon diode, IBA RAZOR. An analytical intensity-modulated dose calculation algorithm designed optimize weight individual Bragg peaks composing field also developed validated.Proton minibeams then obtained brass five slits measuring 2 cm × 400 μm width center-to-center distance 4 mm. measured calculated curves profiles) showed good agreement. Spread-out (SOBP) homogeneous around target intensity modulation peaks, while maintaining spatial fractionation at shallow depths. Mean dose-rates 0.12 0.09 Gy/s one iso-energy layer SOBP conditions presence collimator.This demonstrates on PBS system. It confirms reliability RAZOR detector dosimetry. newly methodology will support future preclinical research pMBRT.