Monte carlo simulation of a 6 MV varian LINAC photon beam using GEANT4-GATE code. (September 2016)

• Record Type: Journal Article
• Authors: Gonias, P.; Zaverdinos, P.; Loudos, G.; Kappas, C.; Theodorou, K.
• Is Part Of: Physica medica. Volume 32(2016)Supplement 3
• Page Start: 333
• Publication Date: 2016-09
• Subjects: Medical physics -- Periodicals; Biophysics -- Periodicals; Biophysics -- Periodicals; Imagerie médicale -- Périodiques; Radiothérapie -- Périodiques; Rayons X -- Sécurité -- Mesures -- Périodiques; Physique -- Périodiques; Médecine -- Périodiques; 610.153
• DOI: 10.1016/j.ejmp.2016.07.245
• Languages: English
• ISSNs: 1120-1797

Abstract

Abstract : Introduction: Monte Carlo simulation of radiation transport is considered to be one of the most accurate methods of radiation therapy dose calculation. Various codes have been used during the years and have been validated for clinical photon beams. GEANT4 Monte Carlo simulation code is originally created for high energy physics and GATE package for the simulation of SPECT/PET systems. New platform of GATE incorporate simulation processes for clinical photon beams by linear accelerators. Purpose: The aim of this work is the validation of a GEANT4-based GATE Monte Carlo (MC) 6 MV photon beam delivered by a medical linear accelerator. Materials and methods: The head of the medical linear accelerator (VARIAN CLINAC 23 EX) of the Metropolitan Hospital was simulated based on the manufacturer's detailed information using the Gate v.7.0 GEANT4 MC code. Two-phase simulation process has been followed: calculation of the phase space (PH) from the linac head and PH transport to a water phantom. The results were compared with measured PDD and OAR data for different field sizes and the simulated model was validated. Results: The simulated and measured dose distributions were in good agreement, in the order of 1%. The statistical relative uncertainty was below of 0.6% for a 10 × 10 cm 2 field in all dosels. Gamma index comparisons were performed: more than 90% simulated points passed the clinical 3%/3 mm gamma criterion. Discussion and Conclusion: The GATE v.7.0 Monte Carlo simulation code has been validated for 6 MV photon beam of a VARIAN medical linear accelerator.