Long-Term Outcome After Liver Transplantation for Hepatocellular Carcinoma Following Yttrium-90 Radioembolization Bridging Treatment.

BACKGROUND Bridging treatments are employed in liver transplant waitlist patients with hepatocellular carcinoma (HCC) because of the risk of tumor progression during the waiting time. Radioembolization is mostly employed in the control of large or multifocal HCCs when other locoregional treatment modalities cannot be applied because of the number or size of lesions. The purpose of this study was to evaluate our experience with the use of radioembolization as a bridge to transplantation and its effect on tumor recurrence and survival after liver transplantation. MATERIAL AND METHODS A retrospective review of 40 consecutive patients with HCC who underwent liver transplantation after radioembolization bridging treatment between January 2007 and December 2015 at the University Hospital Essen, Germany, was performed. Patients' characteristics, alpha-fetoprotein (AFP) levels, pathologic tumor response, tumor recurrence rate, and survival rates were examined through chart review. RESULTS Histopathological examination of the explanted liver specimen revealed complete tumor necrosis in 17 specimens, partial necrosis in 18 specimens, and no significant necrosis in five specimens. Median overall survival was 46 months. Nine patients developed recurrent HCC. Median time from liver transplantation to diagnosis of tumor recurrence was 15 months. There was a trend towards a lower risk of tumor recurrence for patients with complete necrosis on explant specimens. Patients with tumor recurrence demonstrated statistically significantly higher pre- and post-treatment AFP levels (p=0.0234 and p=0.0236) and statistically significantly more frequently microvascular invasion (p=0.0163). CONCLUSIONS Histopathological assessment of explanted livers revealed at least partial necrosis in 87.5% of patients. Patients with successful bridging treatment, i.e. complete necrosis of explant specimens, demonstrate a trend towards a lower risk of tumor recurrence.

External-beam radiotherapy as preparative regimen for hepatocyte transplantation after partial hepatectomy.

PURPOSE: The transplantation of donor hepatocytes is considered a promising option to correct chronic liver failure through repopulation of the diseased organ. This study describes a novel selective external-beam irradiation technique as a preparative regimen for hepatocyte transplantation. METHODS AND MATERIALS: Livers of dipeptidylpeptidase IV (DPPIV)-deficient rats were preconditioned with external-beam single-dose irradiation (25 Gy) delivered to two thirds of the liver. Four days later, a one-third partial hepatectomy (PH) was performed to resect the untreated liver section, and 15 million wild-type (DPPIV+) hepatocytes were transplanted via the spleen into the recipient livers. The degree of donor-cell integration and growth was studied 8 h, 3 days, and 5 and 12 weeks after transplantation. RESULTS: Transplanted hepatocytes integrated rapidly into the irradiated liver and proliferated as clusters, finally repopulating the host liver to approximately 20% hepatocyte mass. After 12 weeks, donor cells and their numerous descendents were fully integrated and expressed functional markers to the same extent as host hepatocytes. CONCLUSIONS: We demonstrate that external-beam liver irradiation is sufficient to achieve partial repopulation of the host liver after hepatocyte transplantation, under the additional stimulus of one-third PH. The method described has potentially good prospects for its application in a clinically viable form of treatment.