臺灣博碩士論文加值系統

本研究採用熱發光劑量計(thermoluminescent dosimeter, TLD) TLD-700及光激發光劑量計(optical stimulated luminescence dosimeter, OSLD)，評估醫用迴旋加速器室內、外光子輻射劑量以及工作人員體外輻射曝露，包含工作人員在放射性藥物氟-18去氧葡萄糖（18F fluorodeoxyglucose, 18F-FDG）調劑、運送放射性藥物時、手指部與全身所接受體外劑量。研究方法是將 TLD與OSLD佈點於工作人員重要器官的身體表面上，以評估工作人員的體外劑量，將劑量計做3度空間棋盤式佈點於運送車、鎢容器(PIG)與迴旋加速器室上，評估工作環境中的光子輻射劑量分佈。
實驗結果顯示，在人員劑量的部份，依工作人員每周調劑18F-FDG的生產活度1500 mCi所花的時間為40 min來推算，該工作人員一年(50周)接受的等價劑量在左眼及右眼分別為15.10 mSv、17.11 mSv，左手及右手分別為267.59 mSv、355.88 mSv；推估一年的有效劑量為8.05 mSv。在運送放射性藥物的部份，鎢容器PIG(屏蔽厚度2.25 cm)內裝填100 mCi的18F-FDG時，在主體周圍的表面劑量率約為2000~3000 μGy之間，距離PIG主體周圍20 cm處之劑量率降至400 μGy左右；在相同條件下，將裝有100 mCi的18F-FDG鎢容器放入運送車(屏蔽厚度2 cm鉛)內，而運送車周圍的最高劑量為30 μGy。評估迴旋加速器使用最大的電流強度35 μA所造成的空間光子劑量分佈，在加速器主體前端的門縫處高劑量區之劑量為12~20 μGy，而在加速器兩側及後方的劑量皆在6~10 μGy劑量區間範圍
內。

This study evaluates radiation dose exposure towards laboratory technicians as a function of the cyclotron measurement device used when drawing out 18F fluorodeoxyglucose ( 18F-FDG) that occurs during processing and transporting if radiation pharmaceuticals. The dose of radiation exposure having accumulated in the technologists is evaluated.
To determine the exposure rate, the study measured containing thermo luminescent dosimeter (TLD-700) and optically stimulated luminescence dosimeter (OSLD). TLD-700 and OSLD were attached at various parts of the body not only to determine the dose of radiation exposure found in a technologist, but also to evaluate the radiation risk exposure to sensitive organs that could be received when drawing out of 18F-FDG studied. The gamma dose distribution was acquired by the 3-plane placements of the TLD-700 and OSLD in the space of cyclotron room and transporting the radiation pharmaceuticals (including automobiles and PIG) and the extrapolation code.
Experimental results indicated that while drawing out 18F-FDG (1500 mCi 40 min weekly) for a year (50 weeks), the hands of a technologist received the highest dose, with an average of the right finger 355.88 mSv y-1 and left finger 267.59 mSv y-1. Additionally, the average equivalent doses with protection to the right eye and left were 17.11 mSv y-1 and 15.10 mSv y-1, respectively. The average whole body effective dose with protection was estimated at 8.05 mSv y-1. While the radiation pharmaceuticals were transported, the PIG (tungsten shield 2.25 cm) carried 100 mCi radiation pharmaceuticals to determine the accumulated 1-hour exposure rate and to evaluate the PIG surface dose. According to those results, at the horizontal plan of height of 20 centimeters, the maximum and mean photon absorption rates are 2000~3000 μGy h-1 at the shielding surface, and at the position of 20 centimeters away from shielding surface, the radiation is reduced 400 μGy h-1. At the same condition, the PIG was placed in a car (lead shield 2 cm) to determine the accumulated 1-hour exposure rate to evaluate the car surface dose. At the horizontal plan of height of 50 centimeters, the maximum and mean photon absorption rates are 30 μGy h-1 at the shielding surface. Devices used include operating the cyclotron for 60 minutes and 35 μA for the beam current, in which the gamma radiation distribution in a cyclotron room were estimated. Experimental results indicated that, at the cyclotron body front, the maximum and mean photon absorption rates are12~20 μGy h-1 at the shielding
surface; at the cyclotron body lateral or posterior shielding surface, those absorption rates are 6~10 μGy h-1.

目 錄
誌謝………………………………………………….……...…………….I
中文摘要 …………………………………………………….…… ….II
英文摘要 …………………………………………………….……….III
目錄 ……………………………………………………...……………..V
圖目錄 …………………………………………………………..…..VII
表目錄 …………………………………………………………….....IX

第一章 緒論
1.1 前言………………………………………....……………….1
1.2 研究背景及目的………………………………………….2
1.3 文獻回顧………………………………..………………….4
第二章 基礎理論
2.1 輻射劑量學
2.1.1吸收劑量………………………………………… 5
2.1.2等價劑量………………………………………… 5
2.1.3有效劑量………………………………………… 6
2.1.4其他組織器官定義……………………… 8
2.1.5輻射生物效應……………………………. 8
第三章 實驗設備與材料
3.1 迴旋加速器中心……………………………………..… 9
3.2 迴旋加速器結構………………………………………. 11
3.3 度量地點介紹………………………………………….. 13
3.4 熱發光劑量計…….……………………………………. 15
3.4.1 TLD計讀儀…………………………………….. 15
3.4.2回火盤與吸取器……………….………... 16
3.4.3氮氣…….………………….……..……………... 16
3.5 光激發光劑量計………………………...……………… 17

第四章 實驗方法與步驟
4.1 TLD準備工作…………………………………………… 20
4.2工作人員之光子劑量評估…………….………………… 25
4.3放射性藥物鎢容器之光子劑量分佈評估.……………… 28
4.4運送車之光子劑量分佈評估.…………………………… 29
4.5迴旋加速器室佈點與照射….…………………………… 32
第五章 結果與討論
5.1工作人員之光子劑量評估.……………………………… 34
5.2放射性藥物鎢容器之光子劑量結果.…………………… 43
5.3運送車之光子劑量結果…...……………….….………… 53
5.4迴旋加速器室光子劑量結果……………….….………… 54
第六章 結論……...…………………………………………………… 65
參考文獻………………………………………………………………. 66

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