Sonographic--histopathologic correlation on human tumor in nude mice treated with percutaneous ethanol injection therapy and radiation therapy

Abstract

Objective: To clarify the relation between ultrasonography and histopathologic findings on tumor treated with percutaneous ethanol injection therapy (PEIT) and radiation therapy.

Materials and methods: Ultrasound-histopathologic correlation was examined in animal models of PEIT and radiation therapy using human tumor xenografts.

Results: The detectability of intratumoral necrosis was correlated with size, distribution, and histologic features of necrosis. Echogenicity of necrosis induced by PEIT varied: coagulation necrosis with few basophilic degenerated nuclei was hyperechoic to viable tumor and easily recognized 7 to 14 days after PEIT. Necrosis, including abundant basophilic nuclei, showed similar echogenicity to viable tumor and was poorly identified. Six hours after radiation therapy, shrunken cells appeared scattered throughout the tumor, but they were not detected by ultrasound.

Conclusion: To evaluate the effectiveness of a treatment with ultrasound through changes of internal echoes, the pattern of cell death also should be considered, which influences echogenicity of treated tumor tissue.