Advanced

Limitations of a pencil beam approach to photon dose calculations in lung tissue

Knöös, Tommy LU ; Ahnesjö, Anders; Nilsson, Per LU and Weber, Lars LU (1995) In Physics in Medicine and Biology 40(9). p.1411-1420
Abstract
A common limitation in treatment planning systems for photon dose calculation is to ignore the impact on electron transport and photon scatter from patient heterogeneities. The heterogeneity correlation is often based on scaling operations along beam rays as for the method according to Batho or the more novel approach of 1D convolutions along beam paths applied in pencil-beam-based systems. The effects of the limitation have been studied in a mediastinum geometry for a wide range of beam qualities by comparing the results from a pencil-beam-based treatment planning system with the results from Monte Carlo calculations. As expected, the deviations within unit-density volumes are small while deviations in low-density volumes increase with... (More)
A common limitation in treatment planning systems for photon dose calculation is to ignore the impact on electron transport and photon scatter from patient heterogeneities. The heterogeneity correlation is often based on scaling operations along beam rays as for the method according to Batho or the more novel approach of 1D convolutions along beam paths applied in pencil-beam-based systems. The effects of the limitation have been studied in a mediastinum geometry for a wide range of beam qualities by comparing the results from a pencil-beam-based treatment planning system with the results from Monte Carlo calculations. As expected, the deviations within unit-density volumes are small while deviations in low-density volumes increase with increasing beam energy from approximately 3% for 4 MV to 14% for 18 MV x-rays as a result of increased electron disequilibrium. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physics in Medicine and Biology
volume
40
issue
9
pages
1411 - 1420
publisher
IOP Publishing
external identifiers
  • pmid:8532755
  • scopus:0029064833
ISSN
1361-6560
DOI
10.1088/0031-9155/40/9/002
language
English
LU publication?
yes
id
1f2cde86-c42e-4a60-92e6-2756e794582a (old id 1108997)
date added to LUP
2008-07-25 11:49:12
date last changed
2017-07-30 03:37:40
@article{1f2cde86-c42e-4a60-92e6-2756e794582a,
  abstract     = {A common limitation in treatment planning systems for photon dose calculation is to ignore the impact on electron transport and photon scatter from patient heterogeneities. The heterogeneity correlation is often based on scaling operations along beam rays as for the method according to Batho or the more novel approach of 1D convolutions along beam paths applied in pencil-beam-based systems. The effects of the limitation have been studied in a mediastinum geometry for a wide range of beam qualities by comparing the results from a pencil-beam-based treatment planning system with the results from Monte Carlo calculations. As expected, the deviations within unit-density volumes are small while deviations in low-density volumes increase with increasing beam energy from approximately 3% for 4 MV to 14% for 18 MV x-rays as a result of increased electron disequilibrium.},
  author       = {Knöös, Tommy and Ahnesjö, Anders and Nilsson, Per and Weber, Lars},
  issn         = {1361-6560},
  language     = {eng},
  number       = {9},
  pages        = {1411--1420},
  publisher    = {IOP Publishing},
  series       = {Physics in Medicine and Biology},
  title        = {Limitations of a pencil beam approach to photon dose calculations in lung tissue},
  url          = {http://dx.doi.org/10.1088/0031-9155/40/9/002},
  volume       = {40},
  year         = {1995},
}