Program Information
Effect of Physics Based Monte Carlo Parameterization On the Accuracy of Transport Quantities
D Patel1*, L Bronk2 , F Guan3 , C Peeler4 , S Brons5 , I Dokic6 , A Abdollahi7 , O Jakel8 , D Grosshans9 , R Mohan10 , U Titt11 , (1) MD Anderson Cancer Center, Houston, TX, (2) UT MD Anderson Cancer Center, Houston, TX, (3) The University of Texas, MD Anderson Cancer Center, Houston, TX, (4) UT MD Anderson Cancer Center, Houston, TX, (5) Heidelberger Ionentherapiezentrum (HIT), Heidelberg, Heidelberg, (6) Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Heidelberg, (7) National Center for Tumor diseases (NCT), Heidelberg, Heidelberg, (8) University of Heidelberg, Heidelberg, ,(9) MD Anderson Cancer Center, Houston, TX, (10) UT MD Anderson Cancer Center, Houston, TX, (11) MD Anderson Cancer Center, Houston, TX
Presentations
MO-RAM-GePD-TT-2 (Monday, July 31, 2017) 9:30 AM - 10:00 AM Room: Therapy ePoster Theater
Purpose: To perform a sensitivity analysis of the physics based Monte Carlo (MC) parameterization on clinically relevant transport quantities such as dose and LETd for proton,helium and carbon ion beams.
Methods: A high throughput experimental setup was custom designed to investigate the relative biological effectiveness (RBE) dependence on the dose and linear energy transfer (LET) values. Specific points along the Bragg curve corresponding to well-defined doses and LET values were chosen by appropriate selection of the pre-absorber thicknesses. The experiment with the proton beam was conducted at the HIT facility in collaboration with the DKFZ in Heidelberg/Germany. Clonogenic assays of two human lung cancer cell lines, H460 and H1437, were investigated in this study. Sensitivity studies were carried out using different physics lists and production cut thresholds to assess their effect on the calculated dose and LET. The translation of these differences in dose and LET on the proton RBE were then studied through the experimental investigation using proton beams.
Results: The sensitivity studies indicate a strong dependence of dose and LET on the choice of physics list. Heavier ions show larger differences. The sensitivity studies based on the production threshold, on the other hand, indicate a smaller effect on the calculated dose and LET values. The proton RBE curve as a function of LET, obtained from the preliminary results, reflects differences based on the use of different sets of MC parameterization.
Conclusion: Sensitivity studies varying the physics based parameterization clearly indicate the importance of conditioning the MC system for each experimental investigation on a case by case basis. The experimental setup is prototyped for its future use in the investigation of the RBE of clinically relevant heavy ion beams.
Funding Support, Disclosures, and Conflict of Interest: This work was supported in part by the Sister Institution Network Funds (SINF) grant, from MD Anderson Cancer Center, Global Academic Programs.
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