Abstract
Purpose: The Molybdenum which is the raw material of $^{99}Mo-^{99m}Tc$ generator is produced from the nuclear reactor. However, output has dwindled as the two nuclear reactors supplying the bulk of radioactive material-one in Chalk River, Ontario and the other in Petten, the Netherlands-have been closed for repairs or maintenance. This resulted in the enhancement of its price. So $^{99}Mo-^{99m}Tc$ generator using$(n,{\gamma})^{99}Mo$ is developed by Korea Atomic Energy Research Institute (KAERI). Medicinal availability of this generator is evaluated in this study. Materials and Methods: The radioactivity of $^{99m}Tc$ eluted in generator 1, 2 and 3 unit developed by KAERI was measured. The quality control test of generator such as appearance test, pH test, LAL test, sterility test, chemical impurity (Al) test and radiochemical purity test were performed. Planar and SPECT/CT image sof SD rat (6 weeks, Female) at 2 hr after injection of $^{99m}Tc-HDP$ (hydroxymethylenediphosphonate) (TechneScan HDP, Malinckrodt Medical, Dutch) and $^{99m}Tc-DPD$ (diphosphono-1, 2-propanedicarboxylicacid) (TECEOS, CIS bio international, France) which were labeled with $^{99m}Tc$ eluted in KAERI and commercial generator (40.5 GBq, Malinckrodt Medical, Dutch) using SPECT/CT camera (Symbia, Siemense, Germany) were obtained respectively. Results: The mean radioactivity of $^{99m}Tc$ elution generator 1unit was 4.18 GBq (113 mCi), generator 2 unit was 4.73 GBq (128 mCi) and generator 3 unit was 3.33 GBq (90 mCi). All quality control tests were within normal limit except pyrogentest. Pyrogen test was positive. Planar and SPECT/CT images of rat injected $^{99m}Tc-HDP$ which was labeled with $^{99m}Tc$ eluted in commercial generator show increased uptake in bone, stomach and bowl. Planar images show increased uptake in liver and bone in case of $^{99m}Tc-DPD$. However, images of rat injected $^{99m}Tc-HDP$ and $^{99m}Tc-DPD$ which were labelled $^{99m}Tc$ eluted in KAERI generator show increased uptake in bone, liver and spleen. Conclusion: If shortcoming is removed such as pyrogen and liver appearance, domestic role as an alternative generator is thought to be able to fill and to secure the national medical service by supplying $^{99m}Tc$ when the supply of $^{99m}Tc$ be comes short.
본 연구의 목적은 한국원자력연구원에서 개발되고 있는 $(n,{\gamma})^{99}Mo/^{99m}Tc$발생기의 성능을 평가하고 개선방안을 연구함으로써 의학적 유효성을 확보하는 것이다. 이를 위해 본 연구에서는 한국원자력연구원에서 제조된 $(n,{\gamma})^{99}Mo/^{99m}Tc$발생기를 이용하여 $^{99m}Tc$ 용출 방사능량 시험, $^{99m}Tc$정도평가, $^{99m}Tc-DPD$, $^{99m}Tc-tetrafomin$ 표지수율 및 동물영상 평가를 진행하였다. 용출 방사능양은 상용 제품에 동일 용량에 비해 다소 적었으나, 발열성 물질 검사를 제외한 전영역의 $^{9m}Tc$정 도평가 실험에서 정상범위를 나타냈다. 표지 수율도 90% 이상 높은 수율을 관찰할 수 있었다. $^{99m}Tc-HDP$와 $^{99m}Tc-DPD$를 주입한 쥐 영상에서 한국 원자력 연구원 발생기는 모두 간과 비장의 집적을 관찰할 수 있었고 간과 비장은 상용발생기 일부에서도 관찰되었다. 이에 원자력 연구원 발생기는 발열성 물질을 제거한다면 비상시 훌륭한 대체 발생기 역할을 수행할 수 있을거라 생각한다.