Premium
Dosimetric evaluation of the OneDose ™ MOSFET for measuring kilovoltage imaging dose from image‐guided radiotherapy procedures
Author(s) -
Ding George X.,
Coffey Charles W.
Publication year - 2010
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 - 10.1118/1.3483099
Subject(s) - dosimeter , image guided radiation therapy , kerma , dosimetry , ionization chamber , calibration , nuclear medicine , detector , dose profile , physics , optics , medical imaging , medical physics , materials science , medicine , ionization , radiology , ion , quantum mechanics
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.