ABSTRACT
Objective To evaluate the safety and efficacy of brachytherapy with 125I seed strand in treating implanted main portal vein tumor thrombus (MPVTT) in experimental rabbits.Methods VX2 tumor cell line was implanted in the main portal vein (MPV) of 32 New Zealand white rabbits to establish MPVTT models.The rabbits were randomly divided into the treatment group (group T,n=16) and the control group (group C,n=16).125I seed strand was implanted in the MPVTT of the rabbits of group T,while blank seed strand was implanted in the MPVTT of the rabbits of group C.After the implantation,the changes in general condition,body weight and laboratory testing results were recorded.Two weeks after the treatment,every 8 rabbits from each group were sacrificed,and the specimens were collected and sent for pathological examination.The remaining rabbits were fed till they died,and then autopsy was conducted.Multi-slice spiral CT manifestations,histopathological findings,Ki-67 labeling index and apoptosis index were used to assess the curative effect,and the results were compared between the two groups.Results At each observation time point after brachytherapy,the weight loss of the experimental rabbits was more obvious in group C than in group T.No statistically significant differences in liver functions and white blood cell count existed between the two groups (P＞0.05).The mean MPVTT volume of group T and group C were (565.40±220.90) mm3 and (2 269.90±437.00) mm3 respectively (P＜0.001);the Ki-67 labeling indexes were (4.14±1.84)％ and (33.82± 6.07)％ respectively (P=0.001);the median survival days were (39.50±2.37) d and (27.38±1.22) d respectively (P=0.001).Conclusion For the treatment of implanted MPVTT in experimental rabbits,brachytherapy with 125I seed strand is safe and effective.