小鼠移植瘤放疗前后^(99)Tc^m-HL91乏氧显像改变的研究

Study of the ^(99)Tc^m-HL91 imaging change before and after radiotherapy in transplant tumors on mice

目的为99Tcm-HL91乏氧显像评价肿瘤放疗疗效提供依据。方法将10只小鼠H22肝癌细胞小鼠移植瘤模型分成两组,每组5只,A组不进行放疗;B组单次放疗25Gy后48h进行99Tcm-HL91显像,计算B组放疗前后同一感兴趣区内肿瘤组织与正常脑组织放射性计数比值(T/N);测定A、B两组G1期和S期细胞所占比例及观察肿瘤组织放疗前后病理变化。结果B组T/N值较放疗前显著降低(P<0.01)。B组S期细胞所占比例明显低于A组,G1期细胞所占比例明显高于A组(P<0.05);B组肿瘤组织光镜下可见凋亡细胞和大量细胞碎片。结论99Tcm-HL91核素显像是一种有价值的评价放疗疗效的影像手段。

Objective To provide a scientific evidence for evaluating the curative effect with ^99Tc^m-HL91 imaging during radiotherapy. Methods 10 transplant tumor mice models of H22 liver carcinoma were divided into 2 groups. Each group included 5mice. Group A was not treated by radiotherapy. In Group B, ^99Tc^m-HL91 imaging was performed 48 h after the radiotherapy ended with a total dose of 25 Gy. The ratio of tumor counts/sec over brain counts/sec （T/N） in the same ROI （region of interest） was calculated before and af- ter radiotherapy in Group B. The cell proportions of G1-phase and S-phase were analyzed by flow cytometry. The pathology change of tumor was observed by microscope before and after radiotherapy. Results The average T/N after radiotherapy was significantly lower than that before radiotherapy in group B（P 〈 0.05）. The average fraction of Gl-phase cell in group B was significantly higher than that in group A, and the average fraction of S-phase cell in group B was significantly lower than that in group A （P 〈 0.05）. We can see apoptosis cells and a lot of cell fragments in tumor tissue after radiotherapy in group C, but there are no any inflammatory cells invading. Conclusion The ^99Tc^m-HL91 imaging was a valuable imaging tool in evaluating radiotherapy effect.