低剂量碳离子束辐射对小鼠移植性肿瘤H_（22）生长的影响

目的：探讨低剂量碳离子束全身照射对小鼠移植性肿瘤H22生长的影响。方法：以小鼠移植性肿瘤H22为实验肿瘤模型,动物分为5组,每组10只。分别为：①空白对照组;②12C6＋本底照射对照组;③12C6＋LDR＋大剂量攻击照射组：（D1＋D2）组;④12C6＋大剂量攻击照射组：D2组;⑤12C6＋诱导剂量组：D1组。观察各组局部照射后10d、20d的肿瘤生长状况,测量肿瘤体积,计算肿瘤抑制率。病理切片观察肿瘤坏死、肿瘤浸润性淋巴细胞情况。结果：与对照组相比,LDR（D1＋D2）组于第10天、20天均具有明显肿瘤抑制作用（P〈0.05-0.01）,且抑制率高于D2组,表明12C6＋束低剂量辐射预处理可明显增强局部肿瘤大剂量照射的抑瘤率。LDR组全身照射小鼠瘤组织周围可见部分坏死组织及淋巴细胞浸润。结论：低剂量碳离子束全身照射可增强局部肿瘤大剂量照射的抑癌作用,其增强效应具有一定的临床参考意义。

Influence of low-dose carbon-ion beam irradiation on the growth of transplanted H22 tumor in mice

Objective:To explore the influence of low-dose carbon-ion beam total body irradiation on the growth of transplanted H22 tumor in mice. Methods:Transplanted H22 tumor in mice were taken as the experimental tumor model, and animals were divided into five groups in which therer was five mice in each group. Respectively,①control group;②12C6+background exposure group;③12C6+LDR+high-dose radiation group:(D1+D2)group;④12C6+high-dose radiation group:D2 group;⑤12C6+induction dose radiation group:D1 group. Tumor growth,tumor volume and tumor inhibition rate were respectively observed and tumor necrosis and tumor infiltrating lymphocytes of tissues were observed by pathological sections after 10d and 20d of local irradiation. Results: There was a significant difference in tumor inhibition rate between LDR(D1+D2) group and control group at 10d and 20d(P<0.05-0.01),and inhibition rate of LDR group was higher than that of D2 group. It suggested that inhibition rate of local tumor was obviously enhanced by 12C6+ beam of low-dose radiation pretreatment. Some residual necrotic tissues and tumor infiltrating lymphocytes in tissues around the tumor treated with total body irradiation were observed. Conclusion: The study suggests that total body irradiation with low-dose carbon-ion beam can enhance tumor inhibition rate after local tumor with high-dose radiation, which can obviously provide clinical reference value.