Percutaneous injection of a low-concentration alkaline solution targeting hepatocellular carcinoma.

We developed a percutaneous low-concentration alkali injection therapy (PLAIT) targeting hepatocellular carcinoma (HCC), and compared the necrotic areas in the livers of rats that had received PLAIT [an alkaline solution of sodium hydroxide (NaOH)] with those that had received percutaneous ethanol injection therapy (PEIT) and percutaneous acetic acid injection therapy (PAIT). The necrotic area increased with increasing concentrations of NaOH solution. The survival rate of rats was 100% up to a concentration of 4 N; however, the rate dropped below 80% with concentrations over 5 N. Also, at a concentration of 2 N, the necrotic area increased with increasing quantities from 0.01 ml to 0.1 ml. PLAIT using 0.05 ml of 2 N NaOH was 1.56 times more effective than PEIT using 0.05 ml of 99.5% ethanol, and 63.33% less effective than PAIT using 0.05 ml of 50% acetic acid. However, the survival rate after PAIT was 50%, while that after PLAIT was 100%. Histopathological observation of normal rat livers after injection of 2 N NaOH at a volume of 0.05 ml showed that the tissue necrosis spread radially from the site immediately after injection by PLAIT, but necroses were not found in other organs. We conclude that PLAIT has promise as a new form of local therapy for HCC.