⁹⁹ᵐTc-HMPAO 표지효율에 대한 고찰

Study on Labeling Efficiency of ⁹⁹ᵐTc-HMPAO

Purpose : The labeling efficiency of radiopharmaceuticals in nuclear medicine is important in terms of accuracy and reliability of the examination. Usually ⁹⁹ᵐTc-HMPAO used for brain SPECT scan is chemically unstable since lots of impurities are existing. Therefore, occurrence of loss of labeling efficiency is easy to appear. In this paper, labeling and use of ⁹⁹ᵐTc-HMPAO should be helpful through experiments on factors affecting the labeling efficiency of ⁹⁹ᵐTc-HMPAO. Materials and Methods : Domestic HMPAO vials (Dong-A) used for brain SPECT scan were tested. Domestic Samyeong Generator 55.5 GBq (1,500 mCi), TLC measurement sets (ITLC-SG, butanone, saline, TLC chamber) and radio-TLC scanner (Advantest, Bioscan) were used. In the first experiment, after eluting generator at 1, 8, 16, 24, 28 hours apart, each eluted ⁹⁹ᵐTc-pertechnetate were labeled with HMPAO and the labeling efficiency was measured. In the second experiment, after eluting ⁹⁹ᵐTc-pertechnetate from a generator, ⁹⁹ᵐTc-pertechnetate was drawn at 0, 1, 3, 6 hours. And each drawn ⁹⁹ᵐTc-pertechnetate were labeled with HMPAO for measuring labeling efficiency. In the third experiment, labeling efficiency was measured at 0, 0.5, 3, 5, 7 hours after labeling ⁹⁹ᵐTc-HMPAO. Results : In the first experiment, measured values were appeared 95.05, 94.64, 94.94, 95.64, 96.76% in passing order of time. In the second experiment, measured values were appeared 94.38, 94.23, 93.26, 91.03% in passing order of time. In the third experiment, measured values were appeared 95.76, 94.17, 88.19, 83.6, 76.86% in passing order of time. Conclusion : In the first experiment of this paper, labeling efficiency of ⁹⁹ᵐTc-HMPAO labeled with ⁹⁹ᵐTc-pertechnetate eluted after 24 hours from first elution. Additional experiments will be needed to discuss for usability. In the second experiment, the labeling efficiency was slightly decreased in chronological order, but it was measured higher than 90%. Also, additional experiments will be needed to discuss for usability. In the third experiment, the labeling efficiency was decreased considerably. Especially, within 3 hours after the labeling is recommended to use ⁹⁹ᵐTc-HMPAO.