Validation of a track repeating algorithm for intensity modulated Carbon therapy with GEANT4

TL;DR

This study validates the Fast Dose Calculator (FDC), a track repeating Monte Carlo algorithm, for carbon ion therapy by comparing its dose calculations with GEANT4 across multiple patient cases, demonstrating high accuracy and clinical suitability.

Contribution

The paper extends the FDC track repeating algorithm from proton to carbon therapy, validating its accuracy for clinical use in carbon ion treatment planning.

Findings

FDC achieves over 90% gamma-index pass rate at 1%/1mm criterion.

Dose-volume-histogram differences are within clinically acceptable limits.

FDC's dosimetric indices show less than 1% RMS difference from GEANT4.

Abstract

The Fast Dose Calculator (FDC), a track repeating algorithm Monte Carlo method was initially developed for proton therapy. The validation for proton therapy has been demonstrated in a previous work. This method can be expanded to ion applications. Our purpose of this paper is to validate the FDC for carbon therapy. We compare the 3D dose distributions and dose-volume-histograms (DVH) for carbon calculated by FDC with a full Monte Carlo method, GEANT 4. 19 patients in total will be discussed, including 3 patients of prostate, 5 of brain, 3 of head and neck, 4 of lung and 4 of spine. We use gamma-index technique to analyse dose distributions and we do dosimetric analysis for DVH, a more direct and informative quantity for planning system assessment. The FDC calculations of both quantities agree with GEANT4. The gamma-index passing rates of all patients discussed in this paper are above 90% with the criterion 1%/1 mm, above 98% with the criterion 2%/2 mm and over 99.9% with the criterion 3%/3 mm. The Root Mean Square (RMS) of percent difference of dosimetric indices D02, D05, D50, D95 and D98 are 0.75%, 0.70%, 0.79%, 0.83% and 0.76%. And all the difference are allowed for clinical use.