title: Estimation of inhomogenity correction factors for a Co-60 beam using Monte Carlo simulation.
abstract: OBJECTIVE
  The aim was to obtain inhomogenity correction factors (ICFs) for lung tissue inhomogenity for a Co-60 teletherapy beam using Monte Carlo simulation and to compare them with factors obtained from a commercially available treatment planning system.
  
  
  METHODS
  The Monte Carlo simulation code of EGSnrc is used for the depth dose calculations. Two clinical like situations were simulated-dose calculation point beyond the lung tissue volume and dose calculation point within the lung tissue volume. The variation of ICF with lung thicknesses and positions was studied. ICF values were obtained for the similar situations from a commercially available treatment planning system, Theraplan Plus.
  
  
  RESULTS
  Percentage depth dose data obtained from Monte Carlo simulation is well matching with the published measurement data. ICFs for lung tissue inhomogenity calculated using the Monte Carlo code are in good agreement with Theraplan Plus TPS values for small inhomogenity thicknesses.
  
  
  CONCLUSIONS
  These results can be used for the verification of TPS calculation or manual treatment time calculation.
authors: Department of Radiotherapy, Government Medical College, Calicut, India. praveenkrd@yahoo.co.in
authors: R D
authors: RD
authors: Praveenkumar
authors: K P
authors: KP
authors: Santhosh
authors: A
authors: A
authors: Augustine
mesh_terms: D001822:Body Burden; D003035:Cobalt; D006801:Humans; D008168:Lung; D008175:Lung Neoplasms / Q000532:radiotherapy*; D015233:Models, Statistical; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D011867:Radioisotope Teletherapy / Q000379:methods*; D011874:Radiometry; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012062:Relative Biological Effectiveness
chemical_list: D003035:Cobalt