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Independent checking of the delivered dose for high-energy X-rays using a hand-held PC

Knöös, Tommy LU ; Johnsson, Stefan LU ; Ceberg, Crister LU ; Tomaszewicz, Andrej LU and Nilsson, Per LU (2001) In Radiotherapy and Oncology 58(2). p.201-208
Abstract
Background and purpose: The requirements on the delivered dose in radical radiation therapy are extremely high. The dose should be within a few percent and also delivered with high accuracy in space. Vendors and users have successfully managed to implement radiation therapy systems, which are able to achieve these demands with high accuracy and reproducibility. These systems include computerized tomography scanners, treatment planning systems, simulators, treatment machines, and record and verify systems. More and more common are also computer networks to assure data integrity when transferring information between the systems. Even if these systems are commissioned and kept under quality assurance programs to maintain their accuracy,... (More)
Background and purpose: The requirements on the delivered dose in radical radiation therapy are extremely high. The dose should be within a few percent and also delivered with high accuracy in space. Vendors and users have successfully managed to implement radiation therapy systems, which are able to achieve these demands with high accuracy and reproducibility. These systems include computerized tomography scanners, treatment planning systems, simulators, treatment machines, and record and verify systems. More and more common are also computer networks to assure data integrity when transferring information between the systems. Even if these systems are commissioned and kept under quality assurance programs to maintain their accuracy, errors may be introduced. Especially, the human factor is an uncontrolled parameter that may introduce errors. Thus, unintentional changes or incorrect handling of data may occur during clinical use of the equipment. Having an independent dose calculation system implemented in the daily quality assurance process may assure a high quality of treatments and avoidance of severe errors.Materials and methods: To accomplish this, a system of equations for calculating the absorbed dose to the prescription point from the set-up information, has been compiled into a dose-calculation engine. The model is based on data completely independent of the treatment planning system (TPS). The fundamental parameter in the dose engine is the linear attenuation coefficient for the primary photons. This parameter can readily be determined experimentally. The dose calculation engine has been programmed into a hand-held PC allowing direct calculation of the dose to the prescription point when the first treatment is delivered to the patient.Results and conclusion: The model is validated with measurements and is shown to be within +/-1.0% (1 SD). Comparison against a state-of-the-art TPS shows an average difference of 0.3% with a standard deviation of +/-2.1%. An action level covering 95% of the cases has been chosen, i.e. +/-4.0%. Deviations larger than this are with a high probability due to erroneous handling of the patient set-up data. This system has been implemented into the daily clinical quality control program. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Radiation therapy, Quality assurance, Monitor calculation, Independent check
in
Radiotherapy and Oncology
volume
58
issue
2
pages
201 - 208
publisher
Elsevier
external identifiers
  • scopus:0035252389
ISSN
1879-0887
DOI
10.1016/S0167-8140(00)00269-3
language
English
LU publication?
yes
id
4912fd4e-623c-4bcf-82bf-f57f82ceda90 (old id 1123084)
date added to LUP
2008-07-01 14:28:19
date last changed
2018-01-07 06:00:19
@article{4912fd4e-623c-4bcf-82bf-f57f82ceda90,
  abstract     = {Background and purpose: The requirements on the delivered dose in radical radiation therapy are extremely high. The dose should be within a few percent and also delivered with high accuracy in space. Vendors and users have successfully managed to implement radiation therapy systems, which are able to achieve these demands with high accuracy and reproducibility. These systems include computerized tomography scanners, treatment planning systems, simulators, treatment machines, and record and verify systems. More and more common are also computer networks to assure data integrity when transferring information between the systems. Even if these systems are commissioned and kept under quality assurance programs to maintain their accuracy, errors may be introduced. Especially, the human factor is an uncontrolled parameter that may introduce errors. Thus, unintentional changes or incorrect handling of data may occur during clinical use of the equipment. Having an independent dose calculation system implemented in the daily quality assurance process may assure a high quality of treatments and avoidance of severe errors.Materials and methods: To accomplish this, a system of equations for calculating the absorbed dose to the prescription point from the set-up information, has been compiled into a dose-calculation engine. The model is based on data completely independent of the treatment planning system (TPS). The fundamental parameter in the dose engine is the linear attenuation coefficient for the primary photons. This parameter can readily be determined experimentally. The dose calculation engine has been programmed into a hand-held PC allowing direct calculation of the dose to the prescription point when the first treatment is delivered to the patient.Results and conclusion: The model is validated with measurements and is shown to be within +/-1.0% (1 SD). Comparison against a state-of-the-art TPS shows an average difference of 0.3% with a standard deviation of +/-2.1%. An action level covering 95% of the cases has been chosen, i.e. +/-4.0%. Deviations larger than this are with a high probability due to erroneous handling of the patient set-up data. This system has been implemented into the daily clinical quality control program.},
  author       = {Knöös, Tommy and Johnsson, Stefan and Ceberg, Crister and Tomaszewicz, Andrej and Nilsson, Per},
  issn         = {1879-0887},
  keyword      = {Radiation therapy,Quality assurance,Monitor calculation,Independent check},
  language     = {eng},
  number       = {2},
  pages        = {201--208},
  publisher    = {Elsevier},
  series       = {Radiotherapy and Oncology},
  title        = {Independent checking of the delivered dose for high-energy X-rays using a hand-held PC},
  url          = {http://dx.doi.org/10.1016/S0167-8140(00)00269-3},
  volume       = {58},
  year         = {2001},
}