小線源治療用QAファントムの作製─使用時点検への応用─

概要

論文の詳細を見る
Purpose: We developed a quality assurance (QA) phantom to enable easy confirmation of radiation source output measurements of a high dose rate 192Ir intracavitary brachytherapy unit in gynecology. The purpose of this study was to evaluate the feasibility of daily checks using the QA phantom. Methods and materials: The QA phantom was designed with tough water phantoms to hold a Farmer-type ionization chamber, with semiconductor detectors used as in vivo dosimeters to measure rectal dose, and three transfer tubes for gynecology. To test the reliability of our QA phantom for the detection of abnormalities in source output or semiconductor detectors, we applied different doses. Results: Variations due to different settings of the QA phantom were within 2%. The temporal variations were less than 2% and 5% in the Farmer-type ionization chamber and semiconductor detectors, respectively. Interobserver variations were below 3%. Conclusions: With tolerance levels of 2% and 5% for a Farmer-type ionization chamber and semiconductor detectors, respectively, a QA phantom is potentially useful for easily detecting abnormalities by applying daily checks of the brachytherapy unit.
公益社団法人日本放射線技術学会の論文