Room: Exhibit Hall
Purpose: The Fast Dose Calculator, 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. The algorithm has been expanded to track carbon and helium ion beams. Our purpose of project is to validate the FDC for carbon therapy.
Methods: We compare the 3D dose distributions and dose-volume-histograms (DVH) for carbon calculated by FDC with GEANT 4, a full Monte Carlo code. A cohort of 19 patients in total was utilized, 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 analyze dose distributions and we do dosimetric analysis for DVHs, a more direct and informative quantity for planning system assessment.
Results: The FDC calculations agree with GEANT4. The gamma-index passing rates of all patients studied in this project are above 98% with the criteria 2%/2mm and over 99.9% with the criteria 3%/3mm. The RMS of percent difference of dosimetric indices D02, D05, D50, D95 and D98 are 1.3%, 1.2%, 0.78%, 0.8% and 1.1%. All such differences are well below the tolerances used in the clinic.
Conclusion: The high gamma index passing rates and low RMS of percent difference for different dosimetric indices show that FDC can be utilized for carbon therapy calculations.
Not Applicable / None Entered.