Dosimetric effect of beam angle on the unflattened and flattened photon beams: A monte carlo study

James C.L. Chow; Amir M. Owrangi

doi:10.1007/978-3-319-19387-8_155

Dosimetric effect of beam angle on the unflattened and flattened photon beams: A monte carlo study

James C.L. Chow, Amir M. Owrangi

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

1 Scopus citations

Abstract

This study compared the variations of depth and surface dose on beam angle between the unflattened and flattened photon beams. Monte Carlo simulation based on the EGSnrc code was used in dose calculation. Phase-space files of the 6 MV photon beams (field size = 10 × 10 cm²) were generated with and without the flattening filter based on a Varian TrueBeam Linac. Depth and surface doses were calculated in a water phantom with angles of the photon beams turning from 0° to 15°, 30°, 45°, 60°, 75° and 90°. Our results showed that compared to the flattened photon beam, the unflattened beam had a higher dose in the build-up region but lower dose beyond the depth of maximum dose. With the Monte Carlo beams cross-calibrated to the machine monitor unit in simulations, dose ratios of the unflattened to flattened beams were in the range of 1.6 – 2.6 with beam angles varying from 0° to 90° in water. In addition, higher surface doses of about 2.5 times were found with beam angles equal to 0o and 15o. However, surface dose deviation between the unflattened and flattened beam became smaller with an increase of beam angle. Using the photon fluence incorporated to the monitor unit, variations of depth and surface dose on the beam angle were investigated and compared. For the unflattened and flattened photon beams, the surface dose and range of depth dose ratios (unflattened to flattened beam) decreased with an increase of beam angle.

Original language	English (US)
Title of host publication	World Congress on Medical Physics and Biomedical Engineering, 2015
Publisher	Springer Verlag
Pages	637-640
Number of pages	4
Volume	51
ISBN (Print)	9783319193878
DOIs	https://doi.org/10.1007/978-3-319-19387-8_155
State	Published - Jan 1 2015
Event	World Congress on Medical Physics and Biomedical Engineering, 2015 - Toronto, Canada Duration: Jun 7 2015 → Jun 12 2015

Other

Other	World Congress on Medical Physics and Biomedical Engineering, 2015
Country	Canada
City	Toronto
Period	6/7/15 → 6/12/15

Keywords

Beam obliquity
Dose calculation
Flattening filter
Monte Carlo simulation
Skin dose
Unflattened photon beam

ASJC Scopus subject areas

Bioengineering
Biomedical Engineering

Access to Document

10.1007/978-3-319-19387-8_155

Fingerprint Dive into the research topics of 'Dosimetric effect of beam angle on the unflattened and flattened photon beams: A monte carlo study'. Together they form a unique fingerprint.

Cite this

Chow, J. C. L., & Owrangi, A. M. (2015). Dosimetric effect of beam angle on the unflattened and flattened photon beams: A monte carlo study. In World Congress on Medical Physics and Biomedical Engineering, 2015 (Vol. 51, pp. 637-640). Springer Verlag. https://doi.org/10.1007/978-3-319-19387-8_155

Chow, JCL & Owrangi, AM 2015, Dosimetric effect of beam angle on the unflattened and flattened photon beams: A monte carlo study. in World Congress on Medical Physics and Biomedical Engineering, 2015. vol. 51, Springer Verlag, pp. 637-640, World Congress on Medical Physics and Biomedical Engineering, 2015, Toronto, Canada, 6/7/15. https://doi.org/10.1007/978-3-319-19387-8_155

@inproceedings{f200a424ee784564ad386c203e791b21,

title = "Dosimetric effect of beam angle on the unflattened and flattened photon beams: A monte carlo study",

abstract = "This study compared the variations of depth and surface dose on beam angle between the unflattened and flattened photon beams. Monte Carlo simulation based on the EGSnrc code was used in dose calculation. Phase-space files of the 6 MV photon beams (field size = 10 × 10 cm2) were generated with and without the flattening filter based on a Varian TrueBeam Linac. Depth and surface doses were calculated in a water phantom with angles of the photon beams turning from 0° to 15°, 30°, 45°, 60°, 75° and 90°. Our results showed that compared to the flattened photon beam, the unflattened beam had a higher dose in the build-up region but lower dose beyond the depth of maximum dose. With the Monte Carlo beams cross-calibrated to the machine monitor unit in simulations, dose ratios of the unflattened to flattened beams were in the range of 1.6 – 2.6 with beam angles varying from 0° to 90° in water. In addition, higher surface doses of about 2.5 times were found with beam angles equal to 0o and 15o. However, surface dose deviation between the unflattened and flattened beam became smaller with an increase of beam angle. Using the photon fluence incorporated to the monitor unit, variations of depth and surface dose on the beam angle were investigated and compared. For the unflattened and flattened photon beams, the surface dose and range of depth dose ratios (unflattened to flattened beam) decreased with an increase of beam angle.",

keywords = "Beam obliquity, Dose calculation, Flattening filter, Monte Carlo simulation, Skin dose, Unflattened photon beam",

author = "Chow, {James C.L.} and Owrangi, {Amir M.}",

year = "2015",

month = jan,

day = "1",

doi = "10.1007/978-3-319-19387-8_155",

language = "English (US)",

isbn = "9783319193878",

volume = "51",

pages = "637--640",

booktitle = "World Congress on Medical Physics and Biomedical Engineering, 2015",

publisher = "Springer Verlag",

note = "World Congress on Medical Physics and Biomedical Engineering, 2015 ; Conference date: 07-06-2015 Through 12-06-2015",

}

TY - GEN

T1 - Dosimetric effect of beam angle on the unflattened and flattened photon beams

T2 - World Congress on Medical Physics and Biomedical Engineering, 2015

AU - Chow, James C.L.

AU - Owrangi, Amir M.

PY - 2015/1/1

Y1 - 2015/1/1

N2 - This study compared the variations of depth and surface dose on beam angle between the unflattened and flattened photon beams. Monte Carlo simulation based on the EGSnrc code was used in dose calculation. Phase-space files of the 6 MV photon beams (field size = 10 × 10 cm2) were generated with and without the flattening filter based on a Varian TrueBeam Linac. Depth and surface doses were calculated in a water phantom with angles of the photon beams turning from 0° to 15°, 30°, 45°, 60°, 75° and 90°. Our results showed that compared to the flattened photon beam, the unflattened beam had a higher dose in the build-up region but lower dose beyond the depth of maximum dose. With the Monte Carlo beams cross-calibrated to the machine monitor unit in simulations, dose ratios of the unflattened to flattened beams were in the range of 1.6 – 2.6 with beam angles varying from 0° to 90° in water. In addition, higher surface doses of about 2.5 times were found with beam angles equal to 0o and 15o. However, surface dose deviation between the unflattened and flattened beam became smaller with an increase of beam angle. Using the photon fluence incorporated to the monitor unit, variations of depth and surface dose on the beam angle were investigated and compared. For the unflattened and flattened photon beams, the surface dose and range of depth dose ratios (unflattened to flattened beam) decreased with an increase of beam angle.

AB - This study compared the variations of depth and surface dose on beam angle between the unflattened and flattened photon beams. Monte Carlo simulation based on the EGSnrc code was used in dose calculation. Phase-space files of the 6 MV photon beams (field size = 10 × 10 cm2) were generated with and without the flattening filter based on a Varian TrueBeam Linac. Depth and surface doses were calculated in a water phantom with angles of the photon beams turning from 0° to 15°, 30°, 45°, 60°, 75° and 90°. Our results showed that compared to the flattened photon beam, the unflattened beam had a higher dose in the build-up region but lower dose beyond the depth of maximum dose. With the Monte Carlo beams cross-calibrated to the machine monitor unit in simulations, dose ratios of the unflattened to flattened beams were in the range of 1.6 – 2.6 with beam angles varying from 0° to 90° in water. In addition, higher surface doses of about 2.5 times were found with beam angles equal to 0o and 15o. However, surface dose deviation between the unflattened and flattened beam became smaller with an increase of beam angle. Using the photon fluence incorporated to the monitor unit, variations of depth and surface dose on the beam angle were investigated and compared. For the unflattened and flattened photon beams, the surface dose and range of depth dose ratios (unflattened to flattened beam) decreased with an increase of beam angle.

KW - Beam obliquity

KW - Dose calculation

KW - Flattening filter

KW - Monte Carlo simulation

KW - Skin dose

KW - Unflattened photon beam

UR - http://www.scopus.com/inward/record.url?scp=84944322986&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84944322986&partnerID=8YFLogxK

U2 - 10.1007/978-3-319-19387-8_155

DO - 10.1007/978-3-319-19387-8_155

M3 - Conference contribution

AN - SCOPUS:84944322986

SN - 9783319193878

VL - 51

SP - 637

EP - 640

BT - World Congress on Medical Physics and Biomedical Engineering, 2015

PB - Springer Verlag

Y2 - 7 June 2015 through 12 June 2015

ER -