99m Tc-MIBI监测肿瘤照射后生物学效应的

目的　研究照射后肿瘤细胞摄取MIBI能力的变化及其与肿瘤细胞凋亡、坏死和增殖状态的关系。方法　将离体肿瘤细胞和实验动物按照射剂量 0、5、10、2 0Gy与照射后 2 4、48、72h进行分组比较。离体肿瘤细胞分别测定单位质量肿瘤细胞摄取99mTc MIBI的放射性计数值 (计数·min- 1 ·mg- 1 cellprotein) ,凋亡指数 (ApoptosisIndex ,AI) ,集落形成率 (Platingefficiency,PE)。实验动物计算肿瘤组织微分摄取率 (differentialuptakeratio,DUR)和AI值。结果　不同剂量照射后 ,肿瘤细胞的99mTc MIBI摄取值与AI值呈负相关 (r=- 0 93) ,与PE值呈正相关 (r =0 84)。 2 4hDUR值与AI负相关 (r=- 0 793)。结论　不同剂量照射后 ,肿瘤细胞活力变化可能用99mTc MIBI作为示踪剂得到反映

Monitoring biological responses of tumor cells after irradiation with 99mTc-MIBI

Objective\ To explore the possibility of using 99m Tc\|MIBI to monitor biological responses of tumor cells after irradiation. Methods\ To observe the relation between the irradiation doses and the uptake levels of 99m Tc\|MIBI by tumor cells irradiated with a single dose of 5 Gy,10 Gy and 20 Gy,respectively.The uptake of 99m Tc\|MIBI in each dose group was determined before and at 24,48,72 hours after irradiation.Apoptosis index (AI) and plating efficiency (PE) of tumor cells were determined simultaneously.The relation between the uptake levels of 99m Tc\|MIBI in vivo (expressed as differential uptake ratio,DUR) and AI was also determined. Results\ There was a negative correlation between uptake levels of 99m Tc\|MIBI and AI ( r=-0 93). A positive correlation was shown between the uptake levels and PE ( r= 0 84).At 24 h after irradiation,DUR was inversely correlated with AI( r=0 793). Conclusion\ It is suggested that 99m Tc\|MIBI might be used as a tracer to monitor the change of viability state of tumor cells after irradiation with different doses.