Commissioning of a medical accelerator photon beam Monte Carlo simulation using wide-field profiles.
A method for commissioning an EGSnrc Monte Carlo simulation of medical linac photon beams through wide-field lateral profiles at moderate depth in a water phantom is presented. Although depth-dose profiles are commonly used for nominal energy determination, our study shows that they are quite insensitive to energy changes below 0.3 MeV (0.6 MeV) for a 6 MV (15 MV) photon beam. Also, the depth-dose profile dependence on beam radius adds an additional uncertainty in their use for tuning nominal energy. Simulated 40 cm x 40 cm lateral profiles at 5 cm depth in a water phantom show greater sensitivity to both nominal energy and radius. Beam parameters could be determined by comparing only these curves with measured data.
Pena
J
J
Departamento de Física de Partículas, Facultade de Física, 15782 Santiago de Compostela, Spain. javierpg@usc.es
Franco
L
L
Gómez
F
F
Iglesias
A
A
Lobato
R
R
Mosquera
J
J
Pazos
A
A
Pardo
J
J
Pombar
M
M
Rodríguez
A
A
Sendón
J
J
D000465:Algorithms; D003198:Computer Simulation; D019544:Equipment Failure Analysis / Q000379:methods* / Q000592:standards*; D008954:Models, Biological; D015233:Models, Statistical; D009010:Monte Carlo Method; D010315:Particle Accelerators / Q000592:standards*; D017785:Photons / Q000627:therapeutic use*; D011785:Quality Assurance, Health Care / Q000379:methods / Q000592:standards; D011835:Radiation Protection / Q000379:methods / Q000592:standards; D011874:Radiometry / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D011879:Radiotherapy Dosage / Q000592:standards; D012680:Sensitivity and Specificity