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.; SPA BIT, 01034 Kiev

doi:10.1118/1.3264176

Title: A silicon strip detector dose magnifying glass for IMRT dosimetry

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Abstract

Purpose: Intensity modulated radiation therapy (IMRT) allows the delivery of escalated radiation dose to tumor while sparing adjacent critical organs. In doing so, IMRT plans tend to incorporate steep dose gradients at interfaces between the target and the organs at risk. Current quality assurance (QA) verification tools such as 2D diode arrays, are limited by their spatial resolution and conventional films are nonreal time. In this article, the authors describe a novel silicon strip detector (CMRP DMG) of high spatial resolution (200 {mu}m) suitable for measuring the high dose gradients in an IMRT delivery. 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 themore »« less

Authors:

Wong, J. H. D.; Carolan, M.; Lerch, M. L. F.; Petasecca, M.; Khanna, S.; Perevertaylo, V. L.; Metcalfe, P.; Rosenfeld, A. B. ^[1]; SPA BIT, 01034 Kiev ^[2]

Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522 (Australia) and Faculty of Medicine, University of Malaya, Kuala Lumpur 50603 (Malaysia)
Ukraine

Publication Date:: Mon Feb 15 00:00:00 EST 2010

OSTI Identifier:: 22096616

Resource Type:: Journal Article

Journal Name:: Medical Physics

Additional Journal Information:: Journal Volume: 37; Journal Issue: 2; Other Information: (c) 2010 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-2405

Country of Publication:: United States

Language:: English

Subject:: 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 61 RADIATION PROTECTION AND DOSIMETRY; 62 RADIOLOGY AND NUCLEAR MEDICINE; CRITICAL ORGANS; DEPTH DOSE DISTRIBUTIONS; DOSIMETRY; HEALTH HAZARDS; IONIZATION CHAMBERS; NEOPLASMS; PHOTONS; PLANNING; POSITION SENSITIVE DETECTORS; QUALITY ASSURANCE; RADIATION DOSES; RADIOTHERAPY; READOUT SYSTEMS; SI SEMICONDUCTOR DETECTORS; SILICON; SPATIAL RESOLUTION; VERIFICATION

Citation Formats


                    Wong, J. H. D., Carolan, M., Lerch, M. L. F., Petasecca, M., Khanna, S., Perevertaylo, V. L., Metcalfe, P., Rosenfeld, A. B., Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522, Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522, St. George Cancer Care Centre, Kogarah, Sydney, New South Wales 2217, SPA BIT, 01034 Kiev, and Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522. A silicon strip detector dose magnifying glass for IMRT dosimetry.  United States: N. p., 2010. 
        Web.  doi:10.1118/1.3264176.

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                    Wong, J. H. D., Carolan, M., Lerch, M. L. F., Petasecca, M., Khanna, S., Perevertaylo, V. L., Metcalfe, P., Rosenfeld, A. B., Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522, Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522, St. George Cancer Care Centre, Kogarah, Sydney, New South Wales 2217, SPA BIT, 01034 Kiev, & Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522. A silicon strip detector dose magnifying glass for IMRT dosimetry.  United States.  https://doi.org/10.1118/1.3264176

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                    Wong, J. H. D., Carolan, M., Lerch, M. L. F., Petasecca, M., Khanna, S., Perevertaylo, V. L., Metcalfe, P., Rosenfeld, A. B., Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522, Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522, St. George Cancer Care Centre, Kogarah, Sydney, New South Wales 2217, SPA BIT, 01034 Kiev, and Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522. 2010.  
        "A silicon strip detector dose magnifying glass for IMRT dosimetry".  United States.  https://doi.org/10.1118/1.3264176.

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@article{osti_22096616,

  title        = {A silicon strip detector dose magnifying glass for IMRT dosimetry},

  author       = {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. and Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522 and Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522 and St. George Cancer Care Centre, Kogarah, Sydney, New South Wales 2217 and SPA BIT, 01034 Kiev and Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522},

  abstractNote = {Purpose: Intensity modulated radiation therapy (IMRT) allows the delivery of escalated radiation dose to tumor while sparing adjacent critical organs. In doing so, IMRT plans tend to incorporate steep dose gradients at interfaces between the target and the organs at risk. Current quality assurance (QA) verification tools such as 2D diode arrays, are limited by their spatial resolution and conventional films are nonreal time. In this article, the authors describe a novel silicon strip detector (CMRP DMG) of high spatial resolution (200 {mu}m) suitable for measuring the high dose gradients in an IMRT delivery. 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.},

  doi          = {10.1118/1.3264176},

  url          = {https://www.osti.gov/biblio/22096616},
  journal      = {Medical Physics},

  issn         = {0094-2405},

  number       = 2,

  volume       = 37,

  place        = {United States},

  year         = {Mon Feb 15 00:00:00 EST 2010},

  month        = {Mon Feb 15 00:00:00 EST 2010}

}

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