PMID- 28516561
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20191120
IS  - 2473-4209 (Electronic)
IS  - 0094-2405 (Linking)
VI  - 39
IP  - 7Part2
DP  - 2012 Jul
TI  - Poster - Thur Eve - 08: A1SL ion chamber charged particle disequilibrium 
      corrections for lung dose measurements using Monte Carlo.
PG  - 4625
LID - 10.1118/1.4740116 [doi]
AB  - An in house inhomogeneous insert for use with ArcCHECK  was developed for dose 
      calculation verification of Stereotactic Body Radiation Therapy (SBRT) lung 
      plans. The inhomogeneous insert has various ion chamber inserts for different 
      geometrical configurations (lung, soft tissue, bone, air). However, the insertion 
      of an ion chamber in a low density medium perturbs the dose to that region by 
      creating Charged Particle Disequilibrium (CPD), limiting the accuracy of ion 
      chamber measurements. By simulating the ion chamber and phantom using Monte 
      Carlo, a correction factor could be calculated and measured to verify the dose 
      difference caused by CPD. BEAMnrc was used to generate a phase space input file 
      for DOSXYZnrc with beam characteristics that matched clinical commissioning data. 
      A model of the A1SL ion chamber geometry (shell, collector, stem, guard) was 
      simulated in a simple water-lung-water slab phantom. Dose to the active area of 
      the ion chamber was measured in several locations throughout the phantom. The 
      active area of the ion chamber was replaced by the surrounding medium; i.e., 
      water or lung within the phantom, and the dose to the same voxels was calculated. 
      The dose was measured on a Linac and the results agreed within 3% and confirmed 
      that the presence of the ion chamber in low density lung perturbs the dose 
      measured in the field by over 31%.
CI  - (c) 2012 American Association of Physicists in Medicine.
FAU - Mulligan, M
AU  - Mulligan M
AD  - London Regional Cancer Program.
FAU - Disher, B
AU  - Disher B
AD  - The University of Western Ontario.
FAU - Fakir, H
AU  - Fakir H
AD  - London Regional Cancer Program.
AD  - The University of Western Ontario.
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Med Phys
JT  - Medical physics
JID - 0425746
OTO - NOTNLM
OT  - Collective models
OT  - Dosimetry
OT  - Ionization chambers
OT  - Linear accelerators
OT  - Lungs
OT  - Monte Carlo methods
OT  - Phase space methods
OT  - Radiation therapy
OT  - Shell model
OT  - Thermodynamic properties
EDAT- 2012/07/01 00:00
MHDA- 2012/07/01 00:01
CRDT- 2017/05/19 06:00
PHST- 2017/05/19 06:00 [entrez]
PHST- 2012/07/01 00:00 [pubmed]
PHST- 2012/07/01 00:01 [medline]
AID - 10.1118/1.4740116 [doi]
PST - ppublish
SO  - Med Phys. 2012 Jul;39(7Part2):4625. doi: 10.1118/1.4740116.