A GPU implementation of a track-repeating algorithm for proton radiotherapy dose calculations

TL;DR

This paper presents a GPU implementation of a track-repeating algorithm for proton radiotherapy dose calculations, achieving near-Monte Carlo accuracy with real-time computation speed suitable for clinical use.

Contribution

The authors developed and validated a GPU-based version of the Fast Dose Calculator, significantly improving speed while maintaining high accuracy in proton dose calculations.

Findings

Reproduces Monte Carlo dose calculations within 2% accuracy.

Achieves dose computation in less than one minute per case.

Enables real-time dose calculation for clinical proton therapy.

Abstract

An essential component in proton radiotherapy is the algorithm to calculate the radiation dose to be delivered to the patient. The most common dose algorithms are fast but they are approximate analytical approaches. However their level of accuracy is not always satisfactory, especially for heterogeneous anatomic areas, like the thorax. Monte Carlo techniques provide superior accuracy, however, they often require large computation resources, which render them impractical for routine clinical use. Track-repeating algorithms, for example the Fast Dose Calculator, have shown promise for achieving the accuracy of Monte Carlo simulations for proton radiotherapy dose calculations in a fraction of the computation time. We report on the implementation of the Fast Dose Calculator for proton radiotherapy on a card equipped with graphics processor units (GPU) rather than a central processing unit architecture. This implementation reproduces the full Monte Carlo and CPU-based track-repeating dose calculations within 2%, while achieving a statistical uncertainty of 2% in less than one minute utilizing one single GPU card, which should allow real-time accurate dose calculations.