32P-磷酸铬-聚L-乳酸缓释粒子近距离放射治疗前列腺癌合并淋巴结转移

32P-chromic phosphate-poly （L-lactide） implantation brachytherapy on prostatic carcinoma with lymphatic metastasis

目的 观察32P-磷酸铬-聚L-乳酸（32P-CP-PLLA）缓释粒子植入对裸鼠前列腺癌实体瘤和区域淋巴结转移灶的治疗作用.方法 建立裸鼠原位前列腺癌及淋巴结转移模型,4周后分别进行高、中、低剂量（剂量分别为3.7、7.4、14.8 MBq）32P-CP-PLLA缓释粒子瘤体局部植入,观察（1）不同剂量32P-CP-PLLA缓释粒子的体内生物学分布;（2）上述缓释粒子对瘤体和淋巴结病理形态学影响以及抑瘤率;（3）观察血WBC和PLT变化,研究其血液不良反应.结果 SPECT显示32P-CP-PLLA缓释粒子植入后主要聚集在瘤体局部和区域淋巴结,形态学检查显示实体瘤和区域淋巴结转移灶瘤组织呈出血、坏死性改变;抑瘤率与给药剂量正相关,给药剂量为3.7、7.4、14.8 MBq,抑瘤率分别为：（70.16±5.48）%、（80.18±5.84）%、（84.97±4.79）%,无明显骨髓抑制反应.结论 32P-CP-PLLA缓释粒子瘤体局部植入对前列腺癌肿瘤组织和区域性淋巴结转移灶具有杀伤作用.

Objective To study the anticancer effects of 32P-chromic phosphate-poly （ L-lactide） （32P-CP-PLI^A） in nude mice with lymphatic metastasis of prostatic carcinoma after implantation brachytherapy. Methods The nude mice were intratumorally implanted with 32P-CP-PLLA of 3.7, 7.4, 14.8 MBq after prostatic carcinoma solid tumor model was established for four weeks. The distribution of 32P in body was observed. The morphology of the tumor and regional lymph nodes was examined. White blood cells and platelets were counted in peripheral blood. Results 32P mainly remained in the tumor and regional lymph nodes. Morphological examination demonstrated that the solid tumor foci necrosed thoroughly, normal structure of regional lymph nodes disappeared, which was replaced by necrotic tissue and hemorrhage. The tumor growth inhibition rate was positively correlated to administration doses. When the doses were 3.7, 7.4, 14.8 MBq, the tumor growth inhibition rate was （70.16 ±5.48）% , （80.18 ±5.84）% , （84.97 ±4.79）% , respectively. No obvious bone marrow depressions were detected. Conclusion The intratumoral implantation with 32P-CP-PLLA can produce anticancer effects on the solid tumor foci and regional lymph nodes.