Commissioning of a medical accelerator photon beam Monte Carlo simulation using wide-field profiles

Phys Med Biol. 2004 Nov 7;49(21):4929-42. doi: 10.1088/0031-9155/49/21/006.

Abstract

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.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Algorithms*
  • Computer Simulation
  • Equipment Failure Analysis / methods*
  • Equipment Failure Analysis / standards*
  • Models, Biological*
  • Models, Statistical
  • Monte Carlo Method
  • Particle Accelerators / standards*
  • Photons / therapeutic use*
  • Quality Assurance, Health Care / methods
  • Quality Assurance, Health Care / standards
  • Radiation Protection / methods
  • Radiation Protection / standards
  • Radiometry / instrumentation
  • Radiometry / methods*
  • Radiometry / standards
  • Radiotherapy Dosage / standards
  • Sensitivity and Specificity