^(18)F-FDG注射液的物理半衰期测定

Determination of physical half-life of ^(18)F-FDG injection

目的测定氟代脱氧葡糖(18 F-FDG)注射液的物理半衰期。方法常规制备18F-FDG注射液,取放射性活度为74 MBq的待测样品,在不同时间点利用精确校准的活度计测量其活度(共测量5次,测量时间间隔10min)。采用Excel表拟合线性回归模型并以线性函数的斜率作为衰变常数(λ),按公式T1/2=Ln2/λ计算物理半衰期。结果 各测量时间点0、10、20、30、40和50min的对应放射性活度对数值分别为0.72、0.65、0.59、0.52、0.46和0.41,拟合线性回归函数为:Y=-0.0063X+0.7154,λ=0.0063,T1/2=110.02min。结论根据核素衰变规律,结合Excel表,可以精确地获得18F-FDG注射液的物理半衰期。

Objective To determine the physical half-life of 18 fluorine deoxyglucose（^18 F-FDG）injection.Methods The 18F-FDG injection with 74 MBq of radioactivity was routinely prepared.The radioactivity values（Ai）of the samples at different time points were measured by precise calibration meter,which was repeated for 5times in an interval time of 10 minutes.Excel chart was used to fit linear regression model with the slope of the linear function as the decay constant（λ）.The physical half-life was calculated according to the formula of T1/2=Ln2/λ.Results The values of radioactivity were 0.72,0.65,0.59,0.52,0.46 and 0.41 for the time points of 0,10,20,30,40 and 50minutes,respectively.The linear regression function was obtained as Y=-0.0063X＋0.7154,λ=0.0063,and T1/2=110.02 minutes.Conclusion Based on the law of radionuclide combined with Excel table,the physical half-life of 18F-FDG injection can be obtained accurately.