Chemoembolization involves threading a small catheter (tube) into the hepatic artery (liver artery) from an anesthetized artery at the top of the leg. Tiny beads called drug-eluting beads are then injected through this catheter directly into the arteries of the cancer deposits where they release a powerful anti-cancer drug into the tumor at very high concentrations for several weeks. Very little of this drug gets into the rest of the body circulation. This therapy is most effective against cancers that arise in the liver (hepatocellular carcinoma and some types of cholangiocarcinoma). It is helpful many times in extending the survival of patients who are not candidates for surgical removal or transplant. It is also used to prevent disease progression in patients awaiting liver transplant. Side effects include pain, nausea and fatigue, but these symptoms generally resolve within a few days to, occasionally, weeks.
Some smaller cancers that can't be removed surgically without significant risk may be treated by freezing them to death where they live using cryoablation. This technique involves placing thin probes into such a tumor using CT guidance. Once the probes are well positioned, Argon gas is circulated through the probe, producing extreme cooling with formation of an "ice ball" at an extremely cold internal temperature of -40 celsius. The ice ball ideally is slightly larger than the targeted lesion. A freeze-thaw-freeze cycle is performed that will usually kill all the tissue within. The body replaces the dead tissue with scar over time. Patients are given mild sedation and liberal local anesthesia. Ice is a natural anesthetic, so the procedure is usually well tolerated. This therapy has been effective in treating small tumors in the kidney, liver, lung and adrenal. It has also been effective in helping with pain control in some bone tumors and larger soft tissue tumors.
New minimally invasive technology allows placement of thin, needle-like microwave probes (antennae) into tumors using local anesthesia and CT or ultrasound guidance. Once the antennae are in place, a microwave ablation zone can be produced in a few minutes. This technique may allow more rapid treatment as well as treatment of larger liver and lung tumors than was possible with radiofrequency ablation.
Radioembolization for the liver
Cancer in the liver has been difficult to treat with external beam radiation therapy in the past because the normal liver is easily injured by radiation. Radioembolization is a technique that allows us to selectively subject cancerous tumors within the liver to high doses of radiation with little risk to the rest of the liver or surrounding organs. This is done, like with chemoembolization, through a tiny catheter threaded into the hepatic artery (liver artery) from an anesthetized artery at the top of the leg. Tiny resin spheres containing y90 are injected carefully through the catheter into the liver circulation. Cancer deposits have many more "parking spaces" for these radioactive spheres than do regions of normal liver tissue. Therefore, the cancer deposits receive far more radiation than does normal liver tissue. Cancers sensitive to radiation may be very effectively controlled with this therapy. We most commonly use this therapy in select patients with metastatic cancer to the liver from colorectal cancer, neuroendocrine cancer, breast carcinoma, GI sarcomas and others. It is also frequently effective in primary liver cancer (hepatocellular carcinoma and intra-hepatic cholangiocarcinoma).The y90 radiation has a half-life of 64.2 hours, which means it's essentially all gone in a few days. It produces beta radiation, which only penetrates about 2.5mm (1/10th inch). So, there is no significant risk of radiation exposure to others around the patient. This therapy, which teams the interventional oncologist with a radiation oncologist, is very well tolerated by most patients, most all of whom go home the same day.
Radiofrequency ablation (RFA) offers a nonsurgical, localized treatment that kills the tumor cells with heat, while sparing nearby healthy lung tissue. Thus, this treatment is much easier on the patient than systemic therapy. Radiofrequency energy can be given without affecting the patient's overall health and most people can resume their usual activities in a few days. It is a safe, minimally invasive tool for local pulmonary tumor control with negligible mortality, little morbidity, short hospital stay, and positive gain in quality of life. In this procedure, the interventional radiologist guides a small needle through the skin into the tumor. From the tip of the needle, radiofrequency energy (similar to microwaves) is transmitted to the tip of the needle, where it produces heat in the tissues. The dead tumor tissue shrinks and slowly forms a scar. It is ideal for nonsurgical candidates and those with smaller tumors.