甲田 正二郎

Shojiro KODA

東邦大学医学部第一内科

The First Department of Internal Medicine, Toho University School of Medicine

キーワード : 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.