Computational modeling of beam-customization devices for heavy-charged-particle radiotherapy

TL;DR

This paper presents a phase-space based model for beam customization in heavy-charged-particle radiotherapy, improving dose calculation accuracy and computational efficiency in treatment planning.

Contribution

It introduces a comprehensive framework that addresses unphysical dependencies in conventional algorithms, enabling precise modeling of collimators and filters in heavy-ion therapy.

Findings

Model verified with submillimeter accuracy in penumbra regions.

Framework effectively resolves collimator-height dependence issues.

Fast and accurate computation suitable for clinical treatment planning.

Abstract

A model for beam customization with collimators and a range-compensating filter based on the phase-space theory for beam transport is presented for dose distribution calculation in treatment planning of radiotherapy with protons and heavier ions. Independent handling of pencil beams in conventional pencil-beam algorithms causes unphysical collimator-height dependence in the middle of large fields, which is resolved by the framework comprised of generation, transport, collimation, regeneration, range-compensation, and edge-sharpening processes with a matrix of pencil beams. The model was verified to be consistent with measurement and analytic estimation at a submillimeter level in penumbra of individual collimators with a combinational-collimated carbon-ion beam. The model computation is fast, accurate, and readily applicable to pencil-beam algorithms in treatment planning with capability of combinational collimation to make best use of the beam-customization devices.