CT导引下125^Ⅰ粒子植入治疗兔VX2肿瘤的实验研究

Study of CT-guided iodine-125 implantation in the treatment of rabbit VX2 tumor

目的探讨CT导引下125I粒子组织间植入兔VX2肿瘤模型对细胞凋亡率的影响。方法在20只兔两侧大腿肌肉内建立VX2肿瘤模型,3周后待肿瘤灶长至直径约2cm备用,每只兔随机选择一侧肿瘤灶作为治疗侧,另一侧作为对照侧,治疗侧在CT导引下经皮穿刺将活度为0.9mCi的125Ⅰ粒子植入肿瘤组织内,对照侧肿瘤灶内植入无活性的空心粒子,于术后即刻、72h、1、2、3周在CT导引下分别穿刺距粒子0.5～1cm、1.0～1.5cm处组织检测细胞凋亡率。结果125Ⅰ粒子植入后即刻、72h、1、2、3周距粒子0.5～1.0cm处对照侧和治疗侧细胞凋亡率分别为(5.43±0.67)%和(5.48±0.66)%(P>0.05),(5.45±0.58)%和(11.60±0.87)%(P<0.05),(6.07±0.69)%和(18.8±0.64)%(P<0.05),(5.94±0.43)%和(37.20±0.39)%(P<0.01),(6.30±0.58)%和(36.56±0.67)%(P<0.01)。距125Ⅰ粒子1.0～1.5cm处各个时间点对照侧与实验侧细胞凋亡率差别均无统计学意义(P>0.05)。结论125Ⅰ粒子组织间植入可诱导肿瘤细胞凋亡,植入后72h细胞凋亡率开始增加,术后2周达高峰并维持在高水平,且随距125Ⅰ粒子的距离增加,细胞凋亡率迅速下降。

Objective To evaluate the effect of CT-guided iodine-125 seed（125^Ⅰ ）implantation to rabbit model VX2 tumor cell apoptosis. Methods VX2 tumor cells were implanted into muscle of 40 rabbits legs, 3 weeks later, as the diameter of tumor reached 2 cm available for test. Randomly selected the sampling tumor on one leg of rabbit as for the test team and tumor on the contralateral leg as for control team. Under CT guidance, 125^Ⅰ seeds were implanted into 20 tumor lesions of the test team, and hollow seeds were implanted into 20 tumor lesions of the control team. Instantly, 72 h, 1, 2, 3 w after operation, percutaneous tumor tissue sampling was done 0.5-1.0 cm and 1.0-1.5 cm away from seed implanted site under CT guidance; and apoptosis was investigated by FCM. Results Instantly, 72 h, 1, 2, 3 w after treatment with iodine-125 （125^Ⅰ ） implantation,the tissue sampling away from seed 0.5-1.0 cm showed the apoptosis rates of control team and test team were respectively as follows： （5.43 ± 0.67）% and （5.48 ± 0.66）%, （P 〉 0.05）, （5.45 ± 0.58）% and （11.60 ± 0.87）%, （P 〈 0.05）, （6.07 ± 0.69）% and （18.8 ± 0.64）%, （P 〈 0.05）, （5.94 ± 0.43）% and （37.20 ± 0.39）%, （P 〈 0.01）, （6.30 ± 0.58）% and （36.56 ± 0.67）%, （P〈 0.01）; and those away from seed implantation site 1.0-1.5 cm in the apoptosis rates showed no significant difference （P 〉 0.05）of the control team and test team. Conclusions 125^Ⅰ seeds implantation can induce tumor cell apoptosis, beginning at 72 h and reached peak at 2 w and kept the high level here afterword. The apoptosis rate descended rapidly along with the increase of distance away from the 125^Ⅰ seedling.