Real-Time In Vivo Dosimetry With MOSFET Detectors in Serial Tomotherapy for Head and Neck Cancer Patients
Abstract
Purpose: A real-time dose verification method using a recently designed metal oxide semiconductor field effect transistor (MOSFET) dosimetry system was evaluated for quality assurance (QA) of intensity-modulated radiation therapy (IMRT). Methods and Materials: Following the investigation of key parameters that might affect the accuracy of MOSFET measurements (i.e., source surface distance [SSD], field size, beam incident angles and radiation energy spectrum), the feasibility of this detector in IMRT dose verification was demonstrated by comparison with ion chamber measurements taken in an IMRT QA phantom. Real-time in vivo measurements were also performed with the MOSFET system during serial tomotherapy treatments administered to 8 head and neck cancer patients. Results: MOSFET sensitivity did not change with SSD. For field sizes smaller than 20 x 20 cm{sup 2}, MOFET sensitivity varied within 1.0%. The detector angular response was isotropic within 2% over 360{sup o}, and the observed sensitivity variation due to changes in the energy spectrum was negligible in 6-MV photons. MOSFET system measurements and ion chamber measurements agreed at all points in IMRT phantom plan verification, within 5%. The mean difference between 48 IMRT MOSFET-measured doses and calculated values in 8 patients was 3.33% and ranged from -2.20% to 7.89%. More thanmore »
- Authors:
-
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center and State Key Laboratory of Oncology in Southern China, Guangzhou 510060 (China)
- Radiation Physics Department, University of Texas, M. D. Anderson Cancer Center, Houston, Texas 77030 (United States)
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2522 (Australia)
- Peter MacCallum Cancer Centre, Melbourne VIC 3002 (Australia)
- Publication Date:
- OSTI Identifier:
- 21587663
- Resource Type:
- Journal Article
- Journal Name:
- International Journal of Radiation Oncology, Biology and Physics
- Additional Journal Information:
- Journal Volume: 80; Journal Issue: 5; Other Information: DOI: 10.1016/j.ijrobp.2010.10.063; PII: S0360-3016(10)03571-6; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0360-3016
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 62 RADIOLOGY AND NUCLEAR MEDICINE; COMPUTERIZED TOMOGRAPHY; CT-GUIDED RADIOTHERAPY; DOSIMETRY; HEAD; IONIZATION CHAMBERS; MOSFET; NECK; NEOPLASMS; PHANTOMS; RADIATION DOSES; BODY; DIAGNOSTIC TECHNIQUES; DISEASES; DOSES; FIELD EFFECT TRANSISTORS; MEASURING INSTRUMENTS; MEDICINE; MOCKUP; MOS TRANSISTORS; NUCLEAR MEDICINE; RADIATION DETECTORS; RADIOLOGY; RADIOTHERAPY; SEMICONDUCTOR DEVICES; STRUCTURAL MODELS; THERAPY; TOMOGRAPHY; TRANSISTORS
Citation Formats
Zhenyu, Qi, Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2522, Deng Xiaowu, E-mail: dengxw@mail.sysu.edu.cn, Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2522, Shaomin, Huang, Shiu, Almon, Lerch, Michael, Metcalfe, Peter, Rosenfeld, Anatoly, and Kron, Tomas. Real-Time In Vivo Dosimetry With MOSFET Detectors in Serial Tomotherapy for Head and Neck Cancer Patients. United States: N. p., 2011.
Web.
Zhenyu, Qi, Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2522, Deng Xiaowu, E-mail: dengxw@mail.sysu.edu.cn, Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2522, Shaomin, Huang, Shiu, Almon, Lerch, Michael, Metcalfe, Peter, Rosenfeld, Anatoly, & Kron, Tomas. Real-Time In Vivo Dosimetry With MOSFET Detectors in Serial Tomotherapy for Head and Neck Cancer Patients. United States.
Zhenyu, Qi, Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2522, Deng Xiaowu, E-mail: dengxw@mail.sysu.edu.cn, Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2522, Shaomin, Huang, Shiu, Almon, Lerch, Michael, Metcalfe, Peter, Rosenfeld, Anatoly, and Kron, Tomas. 2011.
"Real-Time In Vivo Dosimetry With MOSFET Detectors in Serial Tomotherapy for Head and Neck Cancer Patients". United States.
@article{osti_21587663,
title = {Real-Time In Vivo Dosimetry With MOSFET Detectors in Serial Tomotherapy for Head and Neck Cancer Patients},
author = {Zhenyu, Qi and Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2522 and Deng Xiaowu, E-mail: dengxw@mail.sysu.edu.cn and Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2522 and Shaomin, Huang and Shiu, Almon and Lerch, Michael and Metcalfe, Peter and Rosenfeld, Anatoly and Kron, Tomas},
abstractNote = {Purpose: A real-time dose verification method using a recently designed metal oxide semiconductor field effect transistor (MOSFET) dosimetry system was evaluated for quality assurance (QA) of intensity-modulated radiation therapy (IMRT). Methods and Materials: Following the investigation of key parameters that might affect the accuracy of MOSFET measurements (i.e., source surface distance [SSD], field size, beam incident angles and radiation energy spectrum), the feasibility of this detector in IMRT dose verification was demonstrated by comparison with ion chamber measurements taken in an IMRT QA phantom. Real-time in vivo measurements were also performed with the MOSFET system during serial tomotherapy treatments administered to 8 head and neck cancer patients. Results: MOSFET sensitivity did not change with SSD. For field sizes smaller than 20 x 20 cm{sup 2}, MOFET sensitivity varied within 1.0%. The detector angular response was isotropic within 2% over 360{sup o}, and the observed sensitivity variation due to changes in the energy spectrum was negligible in 6-MV photons. MOSFET system measurements and ion chamber measurements agreed at all points in IMRT phantom plan verification, within 5%. The mean difference between 48 IMRT MOSFET-measured doses and calculated values in 8 patients was 3.33% and ranged from -2.20% to 7.89%. More than 90% of the total measurements had deviations of less than 5% from the planned doses. Conclusion: The MOSFET dosimetry system has been proven to be an effective tool in evaluating the actual dose within individual patients during IMRT treatment.},
doi = {},
url = {https://www.osti.gov/biblio/21587663},
journal = {International Journal of Radiation Oncology, Biology and Physics},
issn = {0360-3016},
number = 5,
volume = 80,
place = {United States},
year = {Mon Aug 01 00:00:00 EDT 2011},
month = {Mon Aug 01 00:00:00 EDT 2011}
}