Verification of a pencil beam based treatment planning system: output factors for open photon beams shaped with MLC or blocks
Hansson, H ; Bjork, P ; Knöös, Tommy LU
and Nilsson, Per
LU
(1999)
In Physics in Medicine and Biology
44(9).
p.201-207
- Abstract
- The accuracy of monitor unit calculations from a pencil beam based, three-dimensional treatment planning system (3D TPS) has been evaluated for open irregularly shaped photon fields. The dose per monitor unit was measured in water and in air for x-ray beam qualities from 6 to 15 MV. The fields were shaped either with a multileaf collimator (MLC) or with customized alloy blocks. Calculations from the 3D TPS were compared with measurements. The agreement between calculated and measured dose per monitor unit depended on field size and the amount of blocking and was within 3% for the MLC-shaped fields. The deviation could be traced to limitations in head scatter modelling for the MLC. For fields shaped with alloy blocks, the dose per monitor... (More)
- The accuracy of monitor unit calculations from a pencil beam based, three-dimensional treatment planning system (3D TPS) has been evaluated for open irregularly shaped photon fields. The dose per monitor unit was measured in water and in air for x-ray beam qualities from 6 to 15 MV. The fields were shaped either with a multileaf collimator (MLC) or with customized alloy blocks. Calculations from the 3D TPS were compared with measurements. The agreement between calculated and measured dose per monitor unit depended on field size and the amount of blocking and was within 3% for the MLC-shaped fields. The deviation could be traced to limitations in head scatter modelling for the MLC. For fields shaped with alloy blocks, the dose per monitor unit was calculated to be within 1.6% of measured values for all fields studied. The measured and calculated relative phantom scatter for fields with the same equivalent field size were identical for MLC and alloy shaped fields. These results indicate that the accuracy in the TPS calculations for open irregular fields, shaped with MLC or blocks, is satisfactory for clinical situations. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1114534
- author
- Hansson, H
; Bjork, P
; Knöös, Tommy
LU
and Nilsson, Per
LU
- organization
- publishing date
- 1999
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physics in Medicine and Biology
- volume
- 44
- issue
- 9
- pages
- 201 - 207
- publisher
- IOP Publishing
- external identifiers
-
- pmid:10495127
- scopus:18144453521
- ISSN
- 1361-6560
- language
- English
- LU publication?
- yes
- id
- 8e58dd6c-3292-43eb-9009-75dc8bb9171f (old id 1114534)
- alternative location
- http://www.iop.org/EJ/article/0031-9155/44/9/402/m909n2.pdf
- date added to LUP
- 2016-04-01 12:07:16
- date last changed
- 2022-01-26 23:03:05
@article{8e58dd6c-3292-43eb-9009-75dc8bb9171f,
abstract = {{The accuracy of monitor unit calculations from a pencil beam based, three-dimensional treatment planning system (3D TPS) has been evaluated for open irregularly shaped photon fields. The dose per monitor unit was measured in water and in air for x-ray beam qualities from 6 to 15 MV. The fields were shaped either with a multileaf collimator (MLC) or with customized alloy blocks. Calculations from the 3D TPS were compared with measurements. The agreement between calculated and measured dose per monitor unit depended on field size and the amount of blocking and was within 3% for the MLC-shaped fields. The deviation could be traced to limitations in head scatter modelling for the MLC. For fields shaped with alloy blocks, the dose per monitor unit was calculated to be within 1.6% of measured values for all fields studied. The measured and calculated relative phantom scatter for fields with the same equivalent field size were identical for MLC and alloy shaped fields. These results indicate that the accuracy in the TPS calculations for open irregular fields, shaped with MLC or blocks, is satisfactory for clinical situations.}},
author = {{Hansson, H and Bjork, P and Knöös, Tommy and Nilsson, Per}},
issn = {{1361-6560}},
language = {{eng}},
number = {{9}},
pages = {{201--207}},
publisher = {{IOP Publishing}},
series = {{Physics in Medicine and Biology}},
title = {{Verification of a pencil beam based treatment planning system: output factors for open photon beams shaped with MLC or blocks}},
url = {{http://www.iop.org/EJ/article/0031-9155/44/9/402/m909n2.pdf}},
volume = {{44}},
year = {{1999}},
}