Variations in relative biological effectiveness (RBE) from a fixed value of 1.1 are critical in proton beam therapy. To date, studies estimating RBE at multiple positions relative to the spread-out Bragg peak (SOBP) have been predominantly performed using passive scattering methods, and limited data are available for spot-scanning beams. Thus, to investigate the RBE of spot-scanning beams, Chin...

Double scattering-based proton therapy systems often use patient-specific range compensators for beam modulation. Range compensators adjust the depth in the tissue at which protons reach their Bragg peak. Accurately representing range compensators in Monte Carlo particle transport simulations is a vitally important problem for clinical treatment planning. This paper proposes two new computation...

Introduction: GATE (Geant4 Application for Tomographic Emission) is a Monte Carlo simulation platform developed by the OpenGATE collaboration since 2001 and first publicly released in 2004. In Geant4, each physics process is described by a model (several models are sometimes available for a given physics process) and a corresponding cross-section table. All Geant4 physics model...

Beams of 200 MeV protons and 400 MeV/u fully stripped carbon ions are used for the treatment of solid tumours seated at a maximum depth of 27 cm. More than 100’000 patients have been treated with proton beams and more than 10’000 with carbon ions. Very low proton currents of the order of 1 nA are enough to deliver the typical dose of 2 Gy/l in one minute. In the case of carbon ions the currents...

The biological damages are mainly produced by direct ionization and excitation of bio-molecular DNA electrons or by indirect chemical reaction of water radiolysis products with DNA. In this work, we restricted our study on the interaction of energetic ion proton beams with liquid water; since the water represents over 80% of the most-soft tissues. The proton collisions with water molecules are ...