Examination of beam profile measurement using an imaging plate by the light exposure fading method for quality assurance of external radiation therapy.
High-resolution film dosimetry has been used for several decades to check and to measure two-dimensional dose distributions. However, in recent years, the automatic processor has been replaced by the spread of computed radiography, or has been little used hospitals. In this study, we measured the off-center ratio (OCR) of the open field, after an irradiating radiation beam was delivered to the imaging plate (IP) under conditions in which the IP was exposed to a fixed amount of light with fading, and compared these data with the OCR measured by an ionization-chamber dosimeter, which is the standard method used for measuring radiation dose. Profile measurement using IP could be achieved by performing light fading, even at a range of more than 100 MU. Further, by using a metallic filter, we succeeded in demonstrating that the profile measurement of IP in an open irradiation field could approximate the values of those obtained by an ionization chamber dosimeter. This method can serve as a simple, easy-to-use method for evaluating the QA of dose distribution in radiation therapy.
Fujibuchi
Toshioh
T
Department of Cardiovascular Science and Medicine, Chiba University Graduate School of Medicine.
Funabashi
Nobusada
N
Hashimoto
Masatoshi
M
Abe
Yukinao
Y
Iimori
Takashi
T
Matsubayashi
Fumiyasu
F
Sawada
Kohichi
K
Kurokawa
Masayuki
M
Isobe
Tomonori
T
Kikawa
Takashi
T
Komuro
Issei
I
D005374:Filtration; D008027:Light; D008670:Metals; D009010:Monte Carlo Method; D011785:Quality Assurance, Health Care; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*
D008670:Metals