Trans-arterial Chemoembolization (TACE)
Liver cancer is a very vascular tumor. This means that it contains many blood vessels. These blood vessels come exclusively from the branches of the hepatic artery. In Trans-arterial chemoembolization, a tiny catheter (plastic tube) is passed selectively into the blood vessels supplying the tumor and high dose of chemotherapy drugs are administered directly into the tumor. This is followed by blocking (embolizing) these blood vessels with gel foam or small metal coils. This causes the chemotherapy agents to stay within the tumor and not get washed away with blood flow. High concentration of chemotherapy and lack of blood supply to the tumor leads to death of the cancer cells. In this way the tumor can shrink to 70% of its size.
By blocking blood flow, TACE can also cause some damage to the surrounding liver. This can cause certain side effects such as pain, fever, infection, fluid accumulation, and sometimes, liver failure. Therefore careful selection of patients is important so that side effects can be minimized. TACE is still better than giving no treatment at all. There are newer techniques for delivering chemotherapy directly into the tumor using very small drug-eluting beads. This technique is similar to TACE and is known as DC bead embolization. Side effects seem to be less with DC bead embolization.
While TACE is not suitable for people with very sick livers or who are otherwise medically compromised, it is one of the most widely used techniques to control liver cancer. It is important to realize, that it is not a cure and can only control the cancer for a limited time. However, in many individual patients appropriately chosen by their physicians, TACE can help to keep them alive longer.
TACE can also be used to reduce size of large liver tumors so that patients can then undergo liver transplant more favorably. This is known as “Down-staging of Liver Cancer.”
Trans-arterial Radioembolization (TARE)
Trans-arterial Radioembolization (also known as SIRT, or selective internal radiotherapy) involves attaching a radioactive molecule (called Yttrium) to tiny glass beads. These are then injected directly into the blood vessels feeding the liver cancer (as in TACE). The radiation is then emitted within the liver and this can kill tumor cells. Radioembolization is as effective as TACE but has fewer complications.