Modeling the Biophysical Effects in a Carbon Beam Delivery Line using Monte Carlo Simulation

TL;DR

This study uses Monte Carlo simulations to evaluate the biological effectiveness of a carbon ion beam in therapy, designing a biologically effective dose distribution for clinical application.

Contribution

It introduces a detailed Monte Carlo simulation framework for assessing RBE in a carbon beam delivery system, incorporating the MK model for biological dose estimation.

Findings

RBE varies with depth in water phantom

A biologically effective SOBP was designed

Predicted RBE of mixed beams as a function of depth

Abstract

Relative biological effectiveness (RBE) plays an important role in designing a uniform dose response for ion beam therapy. In this study the biological effectiveness of a carbon ion beam delivery system was investigated using Monte Carlo simulation. A carbon ion beam delivery line was designed for the Korea Heavy Ion Medical Accelerator (KHIMA) project. The GEANT4 simulation tool kit was used to simulate carbon beam transporting into media. An incident energy carbon ion beam in the range between 220 MeV/u and 290 MeV/u was chosen to generate secondary particles. The microdosimetric-kinetic (MK) model is applied to describe the RBE of 10% survival in human salivary gland (HSG) cells. The RBE weighted dose was estimated as a function of the penetrating depth of the water phantom along the incident beam direction. A biologically photon-equivalent Spread Out Bragg Peak (SOBP) was designed using the RBE weighted absorbed dose. Finally, the RBE of mixed beams was predicted as a function of the water phantom depth.