2021年第82回応用物理学会秋季学術講演会

講演情報

一般セッション(ポスター講演)

2 放射線 » 2 放射線(ポスター)

[21a-P07-1~30] 2 放射線(ポスター)

2021年9月21日(火) 11:00 〜 12:40 P07 (ポスター)

11:00 〜 12:40

[21a-P07-4] Pediatric CT dosimetry using a newly designed radiophotoluminescence glass dosimeter

Weishan Chang1,2、Yusuke Koba2 (1.Tokyo Metropolitan Univ.、2.OST NIRS)

キーワード:radiophotoluminescence glass dosimeter, pediatric CT dosimetry

Purpose:
Radiation dose from computed tomography (CT) scans accounts for the largest proportion of medical exposure. Since the lifetime cancer risk is related to the amount of radiation dose, many international organizations have recommended optimizing radiation dose from CT. To optimize the irradiated dose, management of patient dose is necessary. The radiophotoluminescence glass dosimeter (RGD-352M, Dose Ace GD-300 series) has been used to measure dose in the radiation diagnostic field. However, large angular dependence makes CT dosimetry using RGD become difficult. Recently, an additional filter for RGD has been proposed to improve angular dependence. In this study, we proposed a methodology to measure the organ dose in a 5-year-old anthropomorphic phantom by a newly developed RGD dosimetry system and compared it with a web-based CT dose calculator.
Material and methods:
In this study, RGDs were individually calibrated with the ISOVOLT TITAN-320 x-ray generator (GE Inspection Technologies). All the experimental measurements for this study were performed using a CT scanner (SOMATOM Definition Flash, Siemens AG, Forchheim, Germany). To validate the proposed methodology, the measured organ dose was compared with dose calculated by a web-based CT dose calculator WAZA-ARI.
Results:
The calculation results from WAZA-ARI were relatively lower than the measured results with a range of 8 – 20 % which corresponds to the dose difference caused by the difference in effective diameter.