因此本研究選定該院該科為研究評估輻射劑量對象，我們利用經校正後合計552顆，每3顆為一組的高敏感度熱發光劑量劑（TLD-100H），於不同樓層（B1與B2）、不同位置實施周邊環境及廢水管線空間輻射劑量率佈點偵測，為期一個月並依本校放射物理TLD實驗室規劃計測分析。
研究結果發現，於廢水排放系統方面：加速器區域、正子造影中心、SPECT區域、放射免疫分析等區域，其輻射廢水排放管線沿線輻射劑量率，除一個由正子中心洗手間排出經由地下2樓之管線，於車道轉彎處，經量測具有較高輻射劑量率外，其餘各區域所有管線及廢水儲存系統，皆接近背景值。
周邊環境空間輻射劑量率方面：正子造影中心除患者管制等候區量測劑量率高於標準值外，於非管制等候區及控制室、配藥室等區域皆接近背景值；於SPECT/CT檢查區域外之非管制患者等候區，其劑量率高於標準值，其餘區域則依患者停留時間或使用目的而各有高低；放射免疫分析區所有工作區域則完全低於背景值。
The monitoring of radiation dose around the nuclear medicine site is an important study issue today. In this study, TLD-100H radiation dosimeters were used to measure the ambient radiation dose rates around a clinical nuclear medicine site in order to investigate the latent hot zones of radiation exposure.
Results of this study showed that the radiation doses measured from all piping and storage systems were comparable to the background dose. A relatively high dose was observed at the single bend point of waste water piping of the PET/CT. Another important finding was the unexpected high dose rates observed at the non-restricted waiting area (NRWA) of SPECT.
The other main finding is that the unexpected high doses were observed at the waiting areas of SPECT/CT. The possible explanation is that patients may free of control after radiopharmaceutical injection.
To conclude, this study provides useful information for further determination of an appropriate dose reduction strategy to achieve the ALARA principle in a clinical nuclear medicine site.
