Dosimetric evaluation of the OneDose MOSFET for measuring kilovoltage imaging dose from image-guided radiotherapy procedures

Journal Article · Wed Sep 15 00:00:00 EDT 2010 · Medical Physics

DOI:https://doi.org/10.1118/1.3483099· OSTI ID:22096766

Ding, George X.; Coffey, Charles W. ^[1]

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1. Department of Radiation Oncology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, B-902, TVC 1301 Medical Center Drive, Nashville, Tennessee 37232-5671 (United States) and Department of Physics and Astronomy, Vanderbilt University College of Art and Sciences, B-902, TVC, 1301 Medical Center Drive, Nashville, Tennessee 37232-5671 (United States)

Purpose: The purpose of this study is to investigate the feasibility of using a single-use dosimeter, OneDose MOSFET designed for in vivo patient dosimetry, for measuring the radiation dose from kilovoltage (kV) x rays resulting from image-guided procedures. Methods: The OneDose MOSFET dosimeters were precalibrated by the manufacturer using Co-60 beams. Their energy response and characteristics for kV x rays were investigated by using an ionization chamber, in which the air-kerma calibration factors were obtained from an Accredited Dosimetry Calibration Laboratory (ADCL). The dosimetric properties have been tested for typical kV beams used in image-guided radiation therapy (IGRT). Results: The direct dose reading from the OneDose system needs to be multiplied by a correction factor ranging from 0.30 to 0.35 for kilovoltage x rays ranging from 50 to 125 kVp, respectively. In addition to energy response, the OneDose dosimeter has up to a 20% reduced sensitivity for beams (70-125 kVp) incident from the back of the OneDose detector. Conclusions: The uncertainty in measuring dose resulting from a kilovoltage beam used in IGRT is approximately 20%; this uncertainty is mainly due to the sensitivity dependence of the incident beam direction relative to the OneDose detector. The ease of use may allow the dosimeter to be suitable for estimating the dose resulting from image-guided procedures.

• OSTI ID: 22096766
• Journal Information: Medical Physics, Vol. 37, Issue 9; Other Information: (c) 2010 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
61 RADIATION PROTECTION AND DOSIMETRY
62 RADIOLOGY AND NUCLEAR MEDICINE
60 APPLIED LIFE SCIENCES
CALIBRATION
COBALT 60
CORRECTIONS
DOSEMETERS
DOSIMETRY
EVALUATION
IMAGES
IN VIVO
IONIZATION CHAMBERS
KERMA
MOSFET
PATIENTS
RADIATION DOSES
RADIOTHERAPY
SENSITIVITY
X RADIATION
X-RAY DETECTION