Gafchromic EBT film dosimetry in proton beams

Li Zhao, Indra J. Das

Research output: Contribution to journalArticle

72 Citations (Scopus)

Abstract

The depth dose verification of active scanning proton beams is extremely time consuming with ion chamber measurements for beam data commissioning and patient specific measurements. With widespread use of Gafchromic EBT films, two-dimensional high-resolution dosimetry is explored in a uniform scanning proton beam. The EBT films were exposed parallel to the beam axis in a solid water phantom in order to obtain the depth-dose curve in a single measurement and compared with the gold standard measurement with a parallel plate ion chamber in water. Our results demonstrate that EBT films perform well in determining the proton beam range, with uncertainty of 0.5 mm. It is also found that EBT film response is a function of energy over the effective energy of 50-160 MeV proton beams with the variations less than 10%. However, an under-dosage of up to 20% was observed at the peak of the Bragg curve. An empirically derived correction factor is proposed to account for the EBT energy dependence. With corrections, EBT films can be a useful tool for the depth dose verification of active scanning proton beams, thus saving valuable proton beam time.

Original languageEnglish
JournalPhysics in Medicine and Biology
Volume55
Issue number10
DOIs
StatePublished - 2010

Fingerprint

Film Dosimetry
Protons
Ions
Water
Uncertainty

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology

Cite this

Gafchromic EBT film dosimetry in proton beams. / Zhao, Li; Das, Indra J.

In: Physics in Medicine and Biology, Vol. 55, No. 10, 2010.

Research output: Contribution to journalArticle

Zhao, Li ; Das, Indra J. / Gafchromic EBT film dosimetry in proton beams. In: Physics in Medicine and Biology. 2010 ; Vol. 55, No. 10.
@article{0270929f74334a37a43c690f719be48f,
title = "Gafchromic EBT film dosimetry in proton beams",
abstract = "The depth dose verification of active scanning proton beams is extremely time consuming with ion chamber measurements for beam data commissioning and patient specific measurements. With widespread use of Gafchromic EBT films, two-dimensional high-resolution dosimetry is explored in a uniform scanning proton beam. The EBT films were exposed parallel to the beam axis in a solid water phantom in order to obtain the depth-dose curve in a single measurement and compared with the gold standard measurement with a parallel plate ion chamber in water. Our results demonstrate that EBT films perform well in determining the proton beam range, with uncertainty of 0.5 mm. It is also found that EBT film response is a function of energy over the effective energy of 50-160 MeV proton beams with the variations less than 10{\%}. However, an under-dosage of up to 20{\%} was observed at the peak of the Bragg curve. An empirically derived correction factor is proposed to account for the EBT energy dependence. With corrections, EBT films can be a useful tool for the depth dose verification of active scanning proton beams, thus saving valuable proton beam time.",
author = "Li Zhao and Das, {Indra J.}",
year = "2010",
doi = "10.1088/0031-9155/55/10/N04",
language = "English",
volume = "55",
journal = "Physics in Medicine and Biology",
issn = "0031-9155",
publisher = "IOP Publishing Ltd.",
number = "10",

}

TY - JOUR

T1 - Gafchromic EBT film dosimetry in proton beams

AU - Zhao, Li

AU - Das, Indra J.

PY - 2010

Y1 - 2010

N2 - The depth dose verification of active scanning proton beams is extremely time consuming with ion chamber measurements for beam data commissioning and patient specific measurements. With widespread use of Gafchromic EBT films, two-dimensional high-resolution dosimetry is explored in a uniform scanning proton beam. The EBT films were exposed parallel to the beam axis in a solid water phantom in order to obtain the depth-dose curve in a single measurement and compared with the gold standard measurement with a parallel plate ion chamber in water. Our results demonstrate that EBT films perform well in determining the proton beam range, with uncertainty of 0.5 mm. It is also found that EBT film response is a function of energy over the effective energy of 50-160 MeV proton beams with the variations less than 10%. However, an under-dosage of up to 20% was observed at the peak of the Bragg curve. An empirically derived correction factor is proposed to account for the EBT energy dependence. With corrections, EBT films can be a useful tool for the depth dose verification of active scanning proton beams, thus saving valuable proton beam time.

AB - The depth dose verification of active scanning proton beams is extremely time consuming with ion chamber measurements for beam data commissioning and patient specific measurements. With widespread use of Gafchromic EBT films, two-dimensional high-resolution dosimetry is explored in a uniform scanning proton beam. The EBT films were exposed parallel to the beam axis in a solid water phantom in order to obtain the depth-dose curve in a single measurement and compared with the gold standard measurement with a parallel plate ion chamber in water. Our results demonstrate that EBT films perform well in determining the proton beam range, with uncertainty of 0.5 mm. It is also found that EBT film response is a function of energy over the effective energy of 50-160 MeV proton beams with the variations less than 10%. However, an under-dosage of up to 20% was observed at the peak of the Bragg curve. An empirically derived correction factor is proposed to account for the EBT energy dependence. With corrections, EBT films can be a useful tool for the depth dose verification of active scanning proton beams, thus saving valuable proton beam time.

UR - http://www.scopus.com/inward/record.url?scp=77951775866&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77951775866&partnerID=8YFLogxK

U2 - 10.1088/0031-9155/55/10/N04

DO - 10.1088/0031-9155/55/10/N04

M3 - Article

VL - 55

JO - Physics in Medicine and Biology

JF - Physics in Medicine and Biology

SN - 0031-9155

IS - 10

ER -