目的：本研究之目的是以中子活化之 Ho-166 研製肝癌治療核醫藥劑， 測試藥物之穩定性及對肝癌細胞之作用。材料與方法： 將研製之 Ho-165-acetylacetonate （ Ho-165-AcAc ）藥物於清華大學水池式反應器進行中子照射，使 Ho-165 轉換成釋放高能β輻射之 Ho-166 核種。以多頻道能譜分析儀分析藥物核種強度及純度。 所得之 Ho-166-AcAc 以碘化罌粟油攜帶之，並於血清中測試其穩定性，以培養之人類肝癌細胞（ HepG2 cells ）探討藥物對肝癌細胞之作用。結果：Ho-165-AcAc 置於反應器之垂直照射管中照射 10 小時， 所生成之 Ho-166-AcAc 放射比活性可達 16-18 mCi/50 mg，經 120 小時血清中測試結果顯示 Ho-166-AcAc-lipiodol中約有 98 ％的 Ho-166 保存在其油相之中。 HepG2 細胞在 Ho-165-AcAc-lipiodol 處理24 小時後， 顯微鏡下可見有大量 Ho-165-AcAc-lipiodol 脂球積聚其中， 此時細胞內的Ho-165-AcAc 量為 1.3 μ g/10 ?? cells。由施藥時 Ho-166-AcAc-lipiodol 之放射比活性可以估算得細胞中 Ho-166-AcAc-lipiodol 之放射活性。結論：Ho-166-acetylacetonate-lipiodol 攜帶高能β輻射釋出核種，於血清之穩定性高，細胞實驗結果顯示， Ho-165-AcAc-lipiodol 可為肝癌細胞所大量攝入，此體外研究提供未來體內實驗之基本資料，此 Ho-166-AcAc-lipiodol 藥物應可提供肝癌－新的體內輻射治療機會。

　　　　　Objective: The objective of this research was to synthesize and prepareradiopharmaceuticals containing neutron-activated Ho-166. The in vitro stabilityof Ho-166-radiopharmaceuticals was tested, and the interaction of theradiopharmaceuticals with hepatoma cells was investigated.Materials and Methods: In order to generate Ho-166, the non-radioactiveHo-165-acetylacetonate (Ho-165-AcAc) was prepared and irradiated in the TsingHua Open-Pool Reactor. Multiple channel analyzer was used for analysis of theradioactivity and the purity of the Ho-166-AcAc. Lipiodol was used as a carrierof Ho-166-AcAc. The stability of Ho-166-AcAc-lipiodol in serum was tested. Theinteraction of Ho-165-AcAc-lipiodol with human hepatoma cells (HepG2 cells) wasinvestigated. Result: In this study, the prepared Ho-165-AcAc samples wereirradiated in the nuclear reactor for up to 10 hr and yielded 16-18mCi/50mg ofspecific activity. In addition, in vitro analysis of the stability ofHo-166-AcAc-lipiodol in plasma revealed a 98% retention of Ho-166 in theHo-166-AcAc-lipiodol after 120 hr. In vitro treatment of HepG2 cells for 24 hrwith Ho-165-AcAc-lipiodol resulted in a retention of 1.3 μ g of Ho-165-AcAc in10 ?? cells. Thus, from the specific activity of Ho-166-AcAc-lipiodol thepotential radioactivity of Ho-166 in HepG2 cells can be evaluated.Conclusion: Ho-166-AcAc-lipiodol contained sufficient high energy β emitterand has a high stability in serum. In vitro cell culture analysis showed thatlarge amount of Ho-165-AcAc-lipiodol can be uptake by hepatoma cells. Results ofthis In vitro study provided important basic information for future developmentand In vitro tests. The Ho-166-AcAc-lipiodol has potential for future hepatomatherapy.