鈷六十遠隔治療機更換新射源和移機驗收測試

Acceptance Tests of Sourece Renewal and Transportation for AECL-780 Cobalt-60 Teletherapy

林芳仁(Fang-Jen Lin)；吳嘉明(Jia-Ming Wu)；涂振邦(Chen-Pang Tu)；薛文隆(Wen-Long Hsieh)；李財福(Tsair-Fwu Lee)；陳文清(Vicent Cheng)；許順能(Shun-Neng Hsu)

遠隔治療 ； 輻射測試 ； 放射治療設備 ； teletherapy ； radiation, measurement ； therapeutic radiology, equipment

中華放射線醫學雜誌

16卷4期（1991 / 12 / 01）

385 - 390

繁體中文

本科最近更換了已使用多年的CANADA AECL-780鈷60遠隔治療機的射源並且完成從林口長庚移機到高雄分院的作業。首先是作業前準備，先做好各項工作的事前連繫，及記錄拆機前的狀況，已便做為移機後比較的參考。其次是由原廠工程師進行移機前後的拆卸及重組工作和新射源的更換，整個過程並由本院的輻射防護委員會監督射源更換和移機作業的輻防安全。最後是驗收測試，包括輻射的安全，機械、光學和劑量測試，等驗收測試合格後，則須持續進行完整的品質保證後續工作，以維持鈷60遠隔治療機良好而穩定的狀態，我們在此提出有關移機及換射源前後的校驗經驗來供有同型機器者作為參考。

We renewed the decaying source of Cobalt-60 teletherapy unit having been used for more than 10 years and transported the unit from Linkou to Kaoshing recently. Acceptance tests were carried out in detail and items included in mechanical, optical, safety-secuting and dosimetric system. Polystyrene solid phantom, Kodak XV-film and denstometer were used in mechanical tests. All data collected before and after transportation were compared. It was found that mechanical rotation error, including coincidende of collimator and gantry axes with isocenter, was within 2.0 mm. Cross hair isocenter was within 3.0 mm diameter. Mechanical and digitial display error was within 1 degree and 1 sec for angle and time respectively. In optical system, optical distance indicator and light-field size was within 2.0 mm at SAD 80 cm and fields size of 10×10 cm. Light radiation agreement was within 3.0 mm for 10×10 cm. Safety system is in criteria. Emergency off and door interlock was in good condition. RFA-7 water phantom, thimble and parallel-plate ion chambers and Keithley electrometer were used in the following tests: dose rate, tissue-phantom ratio (TPR), field size factor (FSF) percent depth dose (PDD), and virtual source position. Dose rate was measured in air with build-up cap at SAD 80 cm. Detectable errors of TPR, PDD amd FSF were all within 1 and were regarded acceptable. The equivalent couch depth was also measured for clinical use.