以熱發光劑量劑應用於核子醫學科之環境輻射評估

Environmental Radiation Measurements Using TLD at Nuclear Medical Department

張白容(Pai-Jung Chang) ； 黃琪雯(Chi-Wen Huang) ； 高潘福(Pan-Fu Kao) ； 陳健懿(Chien-Yi Chen) ； 劉常潔(Chang-Chieh Liu)

《中華放射線技術學雜誌》 42卷1期 (2018/03) Pp. 15-22

摘要

某醫學大學附設醫院是中部的醫學中心，核子醫學科成立於1999年，新增設的整合式正子斷層暨電腦斷層機（positron emission tomography accompanied with computed tomography, PET/CT）、整合式單光子暨電腦斷層攝影機（single photon emission computed tomography accompanied with computed tomography, SPECT/CT），設立於2007與2011年。PET/CT及SPECT/CT由靶核（鎢、鐵）會放出巨大的X-射線，受檢者與工作人員即可能接受到檢查時的未知洩漏光子，且患者於服用放射藥劑後，即成了活動性射源。因此，在新的PET/CT及SPECT/CT運轉後，可能對患者與工作人員，造成額外的輻射曝露，需要更多的輻射曝露防護，進行核醫科的一個月的佈點/測量，並進行一年量測。使用熱發光劑量計（thermoluminescent dosimeters, TLD-100H）進行輻射量測，並討論對這方法之最小可測劑量（minimum detectable dose, MDD），環境輻射靠近PET/CT變化很大，等候室所測得的劑量為0.14±0.03到0.16±0.02 mSv/mo，注射室及PET/CT控制室最高為0.17±0.02 mSv/mo，工作人員的年劑量，是在可接受範圍內，遠低於ICRP 60的劑量限值。

關鍵字

熱發光劑量計 ； 環境輻射 ； 整合式正子斷層暨電腦斷層機 ； 整合式單光子暨電腦斷層攝影機 ； 最小可測劑量

並列摘要

A Medical University Hospital is a Medical Center in Taichung and its Nuclear Medicine Department (NMD) was founded in 1999. Additionally, new positron emission tomography accompanied with computed tomography (PET/CT) and single photon emission computed tomography accompanied with computed tomography (SPECT/CT) were installed in the NMD, which became fully operational in 2007 and 2011, respectively. These scanners emit substantial X-ray emissions from the target (tungsten, iron). With undergoing PET/CT and SPECT/CT diagnosis, patients and workers are therefore exposure to undesirable photon leakage during scanning X-ray radiation. After administration of radiopharmaceuticals, patients themselves become radioactive sources. This high energy radiation poses different radiation safety problems in NMD. Therefore, it became necessary to evaluate a possible increase of the extra radiations at the NMD due to the operation of the new PET/CT and SPECT/CT of one month survey during one year. An investigation of environmental radiations was performed using thermoluminescent dosimeters (TLD-100H) approach. Minimum detectable dose (MDD) was also discussed herein. Exposure rates varied widely among positions close to the PET/CT facility. Detected exposure rate at waiting room is ranged from 0.14±0.03 to 0.16±0.02 mSv/mo, and up to 0.17 ± 0.02 mSv/mo at PET/CT control room. It is far less than the occupational dose limit recommended by ICRP 60.

並列關鍵字

thermoluminescence dosimety ； environmental radiation ； PET/CT ； SPECT/CT ； minimum detectable dose