Radioembolization is a minimally invasive treatment option for improving the symptoms of liver cancer. It is a dual therapy that makes use of embolization and radiation medical technologies that are delivered straight to the tumor site using a catheter. The embolization blocks a tumor’s blood supply to starve malignant cells so that they die off. Simultaneously, targeted radiation is delivered to the tumor at a high dose via small beads called microspheres. This is different from traditional radiation therapy that applies x-ray beams from outside of the body. Once the beads lodge themselves into tumor tissue, they actively work on reducing the presence of malignant cells. Performed by an interventional radiologist, radioembolization makes use of image guidance for safety and precision.
Why Radioembolization is Performed
A number of treatments can help reduce the size of a liver tumor and improve symptoms in primary liver cancer (hepatocellular carcinoma) and secondary (metastatic) liver cancer. Standard approaches like chemotherapy, external beam radiation, and surgery can be combined with minimally-invasive, highly targeted therapies such as radioembolization. While radioembolization is not a curative treatment, it can help extend life expectancy. Radioembolization is often considered when standard therapies failed to shrink a tumor. It is also an option for patients who may not be surgical candidates because of the size of their tumor or additional medical conditions.
What to Expect During Radioembolization
The patient is given sedative medication through an intravenous (IV) line. After numbing the skin near the femoral artery (a large vessel in the groin), the physician makes a small incision to thread the catheter (thin plastic tube) through to reach the tumor site. This process is aided by imaging guidance (usually CT or ultrasound) to ensure a safe procedure. Once the catheter arrives at the branches of the hepatic (liver) artery that feeds the tumor, the embolization can begin. Tiny beads containing the radiation material (Yttrium-90) are injected through the catheter. The agents become lodged into the blood vessels feeding the tumor. This limits the involvement of any healthy tissue. For the next ten days or so, the beads deliver high dose radiation directly to the diseased cells.
After the injection is complete, the catheter is removed and the small incision site is bandaged. Radioembolization is an outpatient procedure that is usually finished within an hour. Many patients go home later the same day.
Risks and Benefits of Radioembolization
Radioembolization has shown success with delaying further cancer progression as well as shrinking liver tumors. The direct injection of radiation therapy to the tumor allows for higher dosing to be used than if the radiation bean were external to the body. Many people experience mild side effects such as fatigue, nausea, fever, and loss of appetite following an radioembolization. The rate of serious side effects is low but since it is a medical procedure, complications are possible. These include:
- Abdominal ulcers
- Liver failure
- Unintended radiation damage to healthy tissue
The care team will speak with the patient about the risks of the procedure and the steps that are taken to reduce their occurrences.
How to Prepare for Radioembolization
Ahead of the procedure, the care team will review medications and make recommendations around any that must be paused ahead of the embolization. Tests are ordered to identify any potential issues that may arise during or after the procedure. These include routine bloodwork to check overall organ functioning and blood clotting ability, as well as an imaging study called an angiogram (an x-ray of blood vessels). The angiogram helps the physician understand the location of all nearby arteries. After reviewing the angiogram, the physician may preventively seal off select vessels to ensure no radiation reaches the stomach. Next, the doctor simulates treatment with a nuclear medicine tracer. This helps the team understand the path the radiation will take once injected. This also helps the team plan the appropriate treatment dosing in order to spare any impact on healthy organs (such as the lungs).
At the end of the procedure, patients recover under monitoring for several hours. After this period, patients can usually return home. It’s common to experience fatigue for the weeks following the procedure, but overall, most patients resume their normal activities within days. Any lingering abdominal pain or nausea can be treated with over-the-counter medication. Some patients require more than one treatment due to the size of the tumor. If that is the case, a subsequent procedure will be scheduled for about a month after the initial radioembolization.