Morphological Study Of Cavitation In Bone Neoplasm Rabbits Transplanted With VX₂ With High Intensity Focused Ultrasound

Objective:To observe whether the cavity exist in the treatment of vx2 neoplasm rabbits implanted in the tibia with high intensity focused ultrasound (HIFU), and to study the factors which influence the cavitation intensity. Methods:Mammary cancer of human, liver of rabbit was irradiated and VX2 malignant neoplasm implanted in tibia of rabbits were treated with HIFU. Specimens of mammary cancer were gathered from operating room of The First Affiliated Hospital of Chongqing University of Medical Sciences. Observe pathological character immediately after therapy. A total of 70 New Zealand White Rabbits, among them, 10 rabbits were irradiated in liver with HIFU. Pathological character immediately was observed after therapy. Rest of neoplasm rabbits was divided 3 groups randomly. Group A including 30 rabbits,among them,10 rabbits is control group, and 10 rabbits are treated with hyperthermia,another 10 rabbits are treated with HIFU. Kill all the rabbits immediately after therapy and observe their pathological character. Distinguish vacuole nature by lipid and mucus histochemical staining technique examination. Group B including 15 rabbits treated with the same HIFU are killed at different times (1day, 3day, 5day, 7day, 14day after therapy). Group C are treated with HIFU having the same time, different intensity. Kill them immediately after therapy and observe their pathological characteristic. Results:(1) In cytoplasm were mammary cancer, liver of rabbit , group B,C and group A treated with HIFU of bone neoplasm observed a lot of vacuole. Mucus staining and lipid staining were both negative. The vacuole number was significantly higher in HIFU group than in hyperthermia and control group (P<0.001). (2)From immediately to 14day after therapy, the number of cavity gradually decreased. The cavity was hardly observed at 14th day. (3)As the intensity was increased, the number of cavity gradually increased.Conclusion:Cavitation was represented by cavity. Cavity was both observed during irradiation of normal tissue and treatment of tumor with HIFU. The number of cavity gradually decreased with a lapse of several days. The number of cavity gradually rose as the intensity was increased. Cavitation is also important biologic effect of HIFU during treatment of tumor.