2:02 PM Abstract No. 200 - Implantation of Iodine-125 seeds strand for treatment of tumor thrombi in main portal vein: an experimental study in a rabbit model

Abstract

Purpose To establish an animal model of implanted main portal vein tumor thrombi (MPVTT) and to evaluate the therapeutic effect of Iodine-125 seeds strand for treatment of main portal vein tumor thrombi in a rabbit VX2 tumor model. Materials and Methods VX2 tumor thrombi were implanted in the main portal vein of twenty four New Zealand white rabbits. These rabbits were randomly divided into treatment group (Group T, 12 rabbits, T1-T12) and control group (Group C, 12 rabbits, C1-C12). Iodine-125 seeds and blank seeds strand were implanted in the MPV of rabbits in Group T and C, respectively. Changes of general condition and body weight of rabbits in each group were observed after procedure. 2 weeks later, abdominal enhanced CT scan was performed and six rabbits of each group were sacrificed for pathologic examination. The volumes of MPVTT were calculated and extension of metastasis was evaluated. Immunohistochemisty was used to detect the Ki-67 protein and the degree of apoptosis of MPVTT was analyzed by TUNEL. The Ki-67 labeling index (Ki-67 LI) and apoptosis index(AI) were calculated. The survival period of rest animals was recorded. Results Appearance of body weight loss and the cachexia in Group C was earlier than those in Group T. Mean survival period of Group T was longer than that of Group C (38.4 ± 6.19 d VS 26.5 ± 4.46d, p = 0.007). At the 14th day after therapy, mean volume of MPVTT in Group T was significantly smaller than that in Group C (565.4 ± 220.85 mm3 VS 2269.93 ± 437.04 mm3, p = 0.000). Difference in Ki-67 LI and AI between two groups was significant (4.14% ± 1.84% VS 33.82% ± 6.07%, p = 0.000 and 6.51% ± 1.92% VS 0.91% ± 0.26%, p = 0.001, respectively). Conclusion Injecting and suspensory fixing VX2 tumor strip into IVC is a reliable method to establish MPVTT animal model.It was safe and effective for implantation of Iodine-125 seeds strand to treat main portal vein tumor thrombi in a VX2 tumor rabbit model.