^(153)Sm-EDTMP显像测定骨摄取率在个体化治疗剂量计算中的应用

Dosimetry of ^(153) Sm EDTMP therapy by preparative whole body scintigraphy

目的 探讨153 Sm 乙二胺四甲撑膦酸 (EDTMP)全身显像法在个体化给药剂量计算中的价值。方法 对 2 0例骨转移癌患者进行153 Sm EDTMP显像 ,计算骨摄取率 ,并与尿液收集法进行比较。结果 显像法与尿液收集法所测得的骨摄取率之间具有很好的相关性 (r =0 .93)。根据显像法计算的骨摄取率 ,给药剂量为 1.40～ 2 .2 7GBq(平均 1.90GBq) ,骨髓吸收剂量为 1.37～ 1.43Gy(平均1.40Gy)。按标准体重计算 ,则应给予的剂量为 1.75～ 2 .41GBq(平均 2 .18GBq) ,骨髓吸收剂量为1 37～ 2 .2 7Gy(平均 1.63Gy)。两种方法给药剂量之间差异有显著性 (t=4.0 75 ,P =0 .0 0 1) ,骨髓吸收剂量差异也有显著性 (t=4.0 30 ,P =0 .0 0 1)。结论 骨转移癌患者治疗剂量按153 Sm EDTMP显像法测定的骨摄取率进行个体化给药 ,在达到治疗目的的同时 ,还可避免发生骨髓毒性反应 ,具有重要的临床价值。

Objective 153 Sm EDTMP is effective in the palliation of painful bone metastases. We developed a whole body scintigraphy method for preparative individual dosimetry and the results were compared with the 5 h urine collection technique in 20 patients with bone metastases. Methods Anterior and posterior whole body images were obtained using identical acquisition parameters 10 min and 5 h after the intravenous injection of 740 MBq 153 Sm EDTMP. Total counts in each imaging study were corrected with background activity and time of injection, and the bone uptake rate was determined. Bone uptake rate was also calculated from the whole volume of urine collected over 5 h after the administration of an identical dose of the agent, and the two results were compared. Results There was a close correlation between the value obtained from whole body scintigraphy and 5 h urine collection technique ( r =0.93). The therapeutic activity administered in this study was restricted within the permissive limit of bone marrow absorbed dose of 1.4 Gy, in these patients,the therapeutic activity injected was 1.40～2.27 GBq. According to the conventionally recommended administered activity of 37 MBq·kg -1 , the therapeutic activity administered would be 1.75～2.41 GBq, then the bone marrow absorbed dose would reach 1.37～2.27 Gy (mean 1.63 Gy), this may lead to a significant myelotoxicity. Conclusions We have developed a whole body scintigraphic technique which is simple, reliable for custom design of a safe and effective dose of 153 Sm EDTMP for individual patients to palliate cancer pain without myelotoxicity.