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Implantable MOSFET detectors: Evaluation of a new design
Author(s) -
Briere Tina Marie,
Gillin Michael T.,
Beddar A. Sam
Publication year - 2007
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.2799578
Subject(s) - detector , calibration , imaging phantom , dosimetry , reproducibility , nuclear medicine , irradiation , materials science , absorbed dose , beam (structure) , radiation , particle detector , optics , physics , biomedical engineering , medicine , nuclear physics , mathematics , statistics , quantum mechanics
The authors have studied the performance of a new version of the implantable MOSFET detector designed for clinical use. Detectors were irradiated under 6‐ and 18‐MV beams in water at body temperature to the calibration dose of 200 cGy/fraction for 20 daily fractions to determine their response and reproducibility. Additional measurements were performed in a solid phantom under 6‐MV irradiation at room temperature to daily doses of 100, 150, 200, 250, 400 and 600 cGy/fraction. Finally, the angular dependence with respect to rotation about the detector's longitudinal axis was studied. At body temperature, the detectors were found to have an average response within ± 3 % of the calibration dose with a standard deviation of 2 % or less. At room temperature, doses lower than the calibration dose led to a slight overresponse while doses higher than the calibration dose led to a slight underresponse. Angular dependence was not significant, on average within 1.2 % of the mean. When used as specified by the manufacturer, these detectors should provide data useful to verify the delivered dose for external beam radiation therapy within a certain tolerance.