Percutaneous ethanol injection, or PEI, involves injection of alcohol into the center of the tumor, either through the skin or through a more invasive operation. The alcohol dries out cells leading to tumor cell death. PEI has shown some success in treating patients suffering from primary liver cancer, however, it is generally considered ineffective on large tumors.
In order to perform this treatment, tumors must be well vascularized. Unfortunately, many tumors have poor vascularity which prevents effective treatment with PEI. Complications include pain and the potential introduction of alcohol into the bile ducts and major blood vessels. In addition, this procedure can cause cancer cells to be deposited along the needle track when the needle is being withdrawn from the tumor.