A silicon strip detector dose magnifying glass for IMRT dosimetry

Methods: A full characterization of the detector was performed, including dose per pulse effect, percent depth dose comparison with Farmer ion chamber measurements, stem effect, dose linearity, uniformity, energy response, angular response, and penumbra measurements. They also present the applicatio...

Full description

Bibliographic Details
Main Authors: Wong, J.H.D., Carolan, M., Lerch, M.L.F., Petasecca, M., Khanna, S., Perevertaylo, V.L., Metcalfe, P., Rosenfeld, A.B.
Format: Article
Published: The American Association of Physicists in Medicine 2010
Subjects:
_version_ 1825720654145519616
author Wong, J.H.D.
Carolan, M.
Lerch, M.L.F.
Petasecca, M.
Khanna, S.
Perevertaylo, V.L.
Metcalfe, P.
Rosenfeld, A.B.
author_facet Wong, J.H.D.
Carolan, M.
Lerch, M.L.F.
Petasecca, M.
Khanna, S.
Perevertaylo, V.L.
Metcalfe, P.
Rosenfeld, A.B.
author_sort Wong, J.H.D.
collection UM
description Methods: A full characterization of the detector was performed, including dose per pulse effect, percent depth dose comparison with Farmer ion chamber measurements, stem effect, dose linearity, uniformity, energy response, angular response, and penumbra measurements. They also present the application of the CMRP DMG in the dosimetric verification of a clinical IMRT plan. Results: The detector response changed by 23% for a 390-fold change in the dose per pulse. A correction function is derived to correct for this effect. The strip detector depth dose curve agrees with the Farmer ion chamber within 0.8%. The stem effect was negligible (0.2%). The dose linearity was excellent for the dose range of 3-300 cGy. A uniformity correction method is described to correct for variations in the individual detector pixel responses. The detector showed an over-response relative to tissue dose at lower photon energies with the maximum dose response at 75 kVp nominal photon energy. Penumbra studies using a Varian Clinac 21EX at 1.5 and 10.0 cm depths were measured to be 2.77 and 3.94 mm for the secondary collimators, 3.52 and 5.60 mm for the multileaf collimator rounded leaf ends, respectively. Point doses measured with the strip detector were compared to doses measured with EBT film and doses predicted by the Philips Pinnacle treatment planning system. The differences were 1.1%+/- 1.8% and 1.0%+/- 1.6%, respectively. They demonstrated the high temporal resolution capability of the detector readout system, which will allow one to investigate the temporal dose pattern of IMRT and volumetric modulated arc therapy (VMAT) deliveries. Conclusions: The CMRP silicon strip detector dose magnifying glass interfaced to a TERA ASIC DAQ system has high spatial and temporal resolution. It is a novel and valuable tool for QA in IMRT dose delivery and for VMAT dose delivery.
first_indexed 2024-03-06T05:38:24Z
format Article
id um.eprints-15247
institution Universiti Malaya
last_indexed 2024-03-06T05:38:24Z
publishDate 2010
publisher The American Association of Physicists in Medicine
record_format dspace
spelling um.eprints-152472015-12-23T02:41:59Z http://eprints.um.edu.my/15247/ A silicon strip detector dose magnifying glass for IMRT dosimetry Wong, J.H.D. Carolan, M. Lerch, M.L.F. Petasecca, M. Khanna, S. Perevertaylo, V.L. Metcalfe, P. Rosenfeld, A.B. Q Science (General) Methods: A full characterization of the detector was performed, including dose per pulse effect, percent depth dose comparison with Farmer ion chamber measurements, stem effect, dose linearity, uniformity, energy response, angular response, and penumbra measurements. They also present the application of the CMRP DMG in the dosimetric verification of a clinical IMRT plan. Results: The detector response changed by 23% for a 390-fold change in the dose per pulse. A correction function is derived to correct for this effect. The strip detector depth dose curve agrees with the Farmer ion chamber within 0.8%. The stem effect was negligible (0.2%). The dose linearity was excellent for the dose range of 3-300 cGy. A uniformity correction method is described to correct for variations in the individual detector pixel responses. The detector showed an over-response relative to tissue dose at lower photon energies with the maximum dose response at 75 kVp nominal photon energy. Penumbra studies using a Varian Clinac 21EX at 1.5 and 10.0 cm depths were measured to be 2.77 and 3.94 mm for the secondary collimators, 3.52 and 5.60 mm for the multileaf collimator rounded leaf ends, respectively. Point doses measured with the strip detector were compared to doses measured with EBT film and doses predicted by the Philips Pinnacle treatment planning system. The differences were 1.1%+/- 1.8% and 1.0%+/- 1.6%, respectively. They demonstrated the high temporal resolution capability of the detector readout system, which will allow one to investigate the temporal dose pattern of IMRT and volumetric modulated arc therapy (VMAT) deliveries. Conclusions: The CMRP silicon strip detector dose magnifying glass interfaced to a TERA ASIC DAQ system has high spatial and temporal resolution. It is a novel and valuable tool for QA in IMRT dose delivery and for VMAT dose delivery. The American Association of Physicists in Medicine 2010 Article PeerReviewed Wong, J.H.D. and Carolan, M. and Lerch, M.L.F. and Petasecca, M. and Khanna, S. and Perevertaylo, V.L. and Metcalfe, P. and Rosenfeld, A.B. (2010) A silicon strip detector dose magnifying glass for IMRT dosimetry. Medical Physics, 37 (2). pp. 427-439.
spellingShingle Q Science (General)
Wong, J.H.D.
Carolan, M.
Lerch, M.L.F.
Petasecca, M.
Khanna, S.
Perevertaylo, V.L.
Metcalfe, P.
Rosenfeld, A.B.
A silicon strip detector dose magnifying glass for IMRT dosimetry
title A silicon strip detector dose magnifying glass for IMRT dosimetry
title_full A silicon strip detector dose magnifying glass for IMRT dosimetry
title_fullStr A silicon strip detector dose magnifying glass for IMRT dosimetry
title_full_unstemmed A silicon strip detector dose magnifying glass for IMRT dosimetry
title_short A silicon strip detector dose magnifying glass for IMRT dosimetry
title_sort silicon strip detector dose magnifying glass for imrt dosimetry
topic Q Science (General)
work_keys_str_mv AT wongjhd asiliconstripdetectordosemagnifyingglassforimrtdosimetry
AT carolanm asiliconstripdetectordosemagnifyingglassforimrtdosimetry
AT lerchmlf asiliconstripdetectordosemagnifyingglassforimrtdosimetry
AT petaseccam asiliconstripdetectordosemagnifyingglassforimrtdosimetry
AT khannas asiliconstripdetectordosemagnifyingglassforimrtdosimetry
AT perevertaylovl asiliconstripdetectordosemagnifyingglassforimrtdosimetry
AT metcalfep asiliconstripdetectordosemagnifyingglassforimrtdosimetry
AT rosenfeldab asiliconstripdetectordosemagnifyingglassforimrtdosimetry
AT wongjhd siliconstripdetectordosemagnifyingglassforimrtdosimetry
AT carolanm siliconstripdetectordosemagnifyingglassforimrtdosimetry
AT lerchmlf siliconstripdetectordosemagnifyingglassforimrtdosimetry
AT petaseccam siliconstripdetectordosemagnifyingglassforimrtdosimetry
AT khannas siliconstripdetectordosemagnifyingglassforimrtdosimetry
AT perevertaylovl siliconstripdetectordosemagnifyingglassforimrtdosimetry
AT metcalfep siliconstripdetectordosemagnifyingglassforimrtdosimetry
AT rosenfeldab siliconstripdetectordosemagnifyingglassforimrtdosimetry