ABSTRACT
Objective To observe the changes in proliferative capability of remnant tumors implanted in rabbit breast after ablation with high intensity focused ultrasound(HIFU). Methods Rabbit implanted models were established by implanting VX_2 tumor mass into the breast of New Zealand rabbits.HIFU was applied to the tumors,and the remnant tumors were harvested by controlling temperature around probe of tumors.Fifty-six rabbits were randomly divided into control group (n=10)and HIFU group(n=40).The expression of proliferating cell nuclear antigen(PCNA)was detected by immunohistochemistry at different time points after ablation,and the survival time and organ metastasis status were observed after ablation. Results After ablation in HIFU group,the positive expression of PCNA was decreased shortly in remnant tumors,and restored to the level before ablation 21 days after treatment.The survival time in HIFU group was much longer than that in control group,and the time of lung and abdominal viscera metastasis in HIFU group appeared significantly later than that in control group(P<0.05). Conclusion Though HIFU ablation can not completely eradicate tumor after one treatment,the growth and metastasis of remnant tumors can be effectively inhibited for a short time,and HIFU ablation can prolong the survival time.
ABSTRACT
Objective:To observe the pathological changes of VX2 implanted breast cancer ablated by high intensity focused ultrasound (HIFU) in rabbits. Methods:Thirty-six rabbits implanted VX2 breast carcinoma were randomly divided into treatment group (n=24) and control group (n=12) two weeks after implantation. HIFU ablation was performed in the treatment group guided by ultrasound B. The pathological changes were observed under light microscope after hematoxylin-eosin staining and then observed under electron microscope. The activity of succinate dehydrogenase (SDH) was measured. Proliferating cell nuclear antigen (PCNA) was determined by immunohistochemistry. Results:Histopathologic observation found that the morphological features and nucleus karyotypes of tumor cells had no significant changes, but vacuole-like structure appeared in cytoplasm. Typical coagulation necrosis of tumor cells were observed under electron microscope. SDH activity detection showed that tumor cells were inactivated. The expressions of PCNA was positive in control group and negative in treatment group. Conclusion:Electron microscopy, enzyme property test, and immunohistochemistry verified that VX2 implanted breast cancer cells were dead after HIFU ablation in rabbits.