Radium-223 Dichloride의 외부 방사선량의 평가

The Evaluation of External Radiation Exposure dose rate for Radium-223 Dichloride

Purpose ²²³Ra-Dichloride is used for the medicine of castration-resistant prostate cancer (CRPC) and which emits α-ray of 28 Mev that is used for therapy. However ²²³Ra-Dichloride emits β-ray of 3.6% and γ-ray of 1.1%(80,156,270 keV) aside from α-ray in decay. Therefore we would like to evaluate external radiation expose dose rate of γ-ray of ²²³Ra-Dichloride. Materials and Methods We calculated external radiation expose dose rate using γ-constant of ²²³Ra-Dichloride, ⁹⁹ᵐTc based on Health physics(2012). ²²³Ra-Dichloride of 3.5 M㏃ and ⁹⁹ᵐTc-MDP of 740 M㏃ were applied. external radiation expose dose rate 15 times from 1m by survey meter. Results γ-contant of ²²³Ra, ⁹⁹ᵐTc-MDP from 1m distance based on Health physics(2012) is 0.0469, 0.0215. calculated value of external radiation expose dose rate was 16 μ㏜, 34 μ㏜ which activity is ²²³Ra-Dichloride of 3.5 MBq and ⁹⁹ᵐTc-MDP of 740 M㏃ from 1 m . and measured mean value of 1 m was 0.7 μ㏜/h, 18 μ㏜/h. Conclusion γ-constant of ²²³Ra is higher than ⁹⁹ᵐTc based on Health physics(2012). however calculated maximum external radiation expose dose rate of ²²³Ra-Dichloride is lower than ⁹⁹ᵐTc due to actually used quantity of activity of ²²³Ra-Dichloride is small. measured value of ²²³Ra-Dichloride is also lower than ⁹⁹ᵐTc-MDP. Therefore external radiation expose dose rate of γ-ray of ²²³Ra-Dichloride is very low.