Antitumor Effects of Transcatheter Arterial Embolization with Mitomycin C Microcapsules and Spongostan on VX2 Implanted Hepatic Tumors -Comparative Study of Ultrasonographical and Histopathological Findings-
The First Department of Internal Medicine, Toho University School of Medicine
VX<SUB>2</SUB> implanted hepatic tumor, Mitomycin C microcapsule, Transcatheter arterial embolization, Ultrasonography, Histopathological findings
We explored the antitumor effects of intra-arterial injection with Mitomycin C microcapsules (MMC-mc), 225 μm in diameter, in comparison with intra-arterial injection of spongostan, 0.5 mm in diameter, on VX2 hepatic tumors implanted in 55 rabbits, in terms of serum concentration of MMC, growth rate of the tumor, ultrasonographical images and histopathological findings.
Before treatment, VX2 tumors, each about 20 mm in diameter, were found by echography to be hyperechoic in the center, with the rest of the tumor being hypoechoic; histopathologically they showed well-circumscribed nodular lesions with central multifocal necrosis. The tumor growth was as well suppressed in the MMC-mc (1 mg/kg) group as in the TAE group. The serum concentration of MMC proved to be (73.33±10.47)×10-4 μg/ml 48 hours after treatment. Echographically, in the MMC-mc group, strongly hyperechoic spots were observed in the tumor after 15 minutes. However, after 24 hours, there appeared a very strong, almost anechoic, hypoecho in the center, a hyperecho around it, and hypoecho in the periphery. Four days after treatment, the tumors were occupied with an overall very strong hypoecho, demarcated with a marginal ring-like hyperecho. In the TAE group, the tumors became hypoechoic, whereas the surrounding liver tissue became rather hyperechoic. Histopathologically, the tumors underwent degeneration and necrosis both in the MMC-mc group and in the TAE group, but infarction was stronger and more widespread in the latter.