Enhancement of leukocyte adhesion after percutaneous irradiation in rats with hepatocellular carcinoma

AIM: To evaluate the effects of percutaneous radiation on leukocyte-endothelium interaction (LEI) in experimental hepatocellular carcinoma (HCC). METHODS: Twelve ACI rats underwent HCC-inoculation, six of which on day 12 received low-dose external radiation and six did not. After 12 h intravital microscopy was performed. RESULTS: LEI was significantly reduced in tumor tissue. However, irradiation of liver sinusoids and tumor tissue with 6 Gy led to a significant activation of leukocyte adhesion in the tumor with a marked increase of the proinflammatory cytokine TNF-α. CONCLUSION: The findings indicate that the immunological tumor-endothelial barrier can be overcome by external irradiation.