The aim of this paper is to present the comparison of three models of Local Effect Model (LEMI, LEMII, LEMIII) with penetration depth of proton in a typical Spread-Out Bragg Peak (SOBP) for cell Survival Fraction (CSF) of HTB140 cell line.To evaluate the CSF, two tools, GEANT4 code and SURVIVAL code, were used. The dose and Linear Energy Transfer (LET) output of GEANT4 were used as input of SURVIVAL code for calculation of CSF parameters (alpha and beta) using three versions of LEM (LEMI, LEMII, and LEMIII). By using the Linear-Quadratic (LQ) model and output of survival code, the curve of CSF was predicted for HTB140 cell line and reasonable agreement with experimental data of CATANA (Centro di AdroTerapia ed Applicazioni Nucleari Avanzate) center was achieved. At 2 Gy, by moving from proximal to distal end of SOBP, the CSF of LEMI decreased from 0.94 to 0.92 and then increased to 0.97 at distal declining edge but LEMII and LEM III increased from 0.89 to 0.96 and 0.9 to 0.96 (proximal and distal declining edge) respectively.This is the first study to compare LEMI, LEMII, and LEMIII models for CSF curve of proton with penetration depth and was coupled both GEANT4 and SURVIVAL code to predict the CSF parameter. According to results, the prediction of the LEMII and LEMIII were in better agreement with experimental results as compared to the LEMI model.
Read full abstract