Selective Internal Radioembolization with SIR-Spheres (SIRT) for Liver Tumors/Metastases | Uniclinic Frankfurt, Germany

SIRT is a treatment used for liver tumors, which involves the use of millions of tiny radioactive beads known as SIR-Spheres microspheres. These microspheres are directly delivered into the liver tumors. The development of SIR-Spheres microspheres began in Australia in the 1980s, and in 2002, they were officially approved in Europe and the United States. Before the SIRT treatment, your treatment team will ask you about your cancer history and any other complaints you may have. They will then carry out a series of initial tests to ensure that you are safe to receive SIRT. Patients typically undergo two procedures under local anesthesia. Both procedures involve a radiological procedure known as angiography. The first angiogram, also called "mapping," aims to prepare your liver for SIRT treatment. During mapping, your interventional radiologist closes (embolizes) vessels to minimize the possibility of the microspheres reaching areas outside the liver, such as the stomach or intestines. You will also be given a small amount of a radioactive dye to determine how much blood flows from the liver to the lungs. If these initial tests produce acceptable results, the dose of the SIR-Spheres is determined. The SIR-Spheres microspheres are then administered in a second procedure, which is usually carried out one to two weeks after the first tests have been completed. The interventional radiologist makes a small incision, usually in the femoral artery near the groin, and inserts a small, flexible tube, also known as a catheter, through the artery into the liver. The SIR-Spheres microspheres are administered through this catheter. The entire procedure can take approximately 90 minutes. You will be tired during the procedure, but you will be able to communicate with your treating doctor and the team. The SIRT procedure allows radiation, a treatment commonly used to treat cancer, to be delivered directly to liver tumors, taking advantage of the tumor's blood supply. About 90% of the blood supply to normal liver tissue comes from the portal vein, which comes from the intestine, while about 90% of the blood supply to liver tumors comes from the hepatic artery. The SIR-Spheres microspheres are specifically introduced into the liver tumors via the hepatic artery so that the remaining healthy liver tissue is exposed to as little strain as possible. Most microspheres are approximately 32 microns in diameter, which is about a third of the width of a human hair. The microspheres are small enough to flow through the hepatic arteries but too large to pass through the small blood vessels within the tumor, where they then become permanently trapped in the tumor bed. The SIR-Spheres microspheres contain the radioactive element yttrium-90, which emits beta radiation over a relatively short distance: an average of 2. 4 mm in human tissue. Yttrium-90 has a half-life of about two and a half days. Therefore, the majority of radiation (over 97%) reaches the tumor within the first two weeks after treatment. Since the SIR-Spheres microspheres are introduced directly into the tumors, a higher radiation dose can be applied locally than with conventional external radiation therapy. Clinical data shows that SIR-Spheres microspheres, used in combination with chemotherapy, can shrink patients' liver tumors more than with chemotherapy alone, as well as improve quality of life and increase life expectancy. In some patients, the treatment can shrink the liver tumors to such an extent that they can be surgically removed at a later date. In patients whose liver tumors no longer respond to chemotherapy, SIR-Spheres microspheres have also been successfully used to shrink these tumors and prolong patient survival. Many scientific publications have documented the use of SIR-Spheres microspheres in treating patients with liver metastases or primary liver cancer. After undergoing SIRT treatment, you may need to undergo a scan to ensure that the SIR-Spheres microspheres have been infused into your liver. The medical team will monitor you for a few hours after the treatment to determine if you experience any side effects or complications that may require additional medication. As you have received radioactive treatment, you need to take some simple precautions in the first 24 hours after SIRT treatment, such as washing your hands thoroughly after using the toilet and cleaning up any spilled bodily fluids, such as blood, urine, or stool, and disposing of them in the toilet. For more information on these precautions, you can contact your healthcare team. Your treatment progress will be monitored by the medical team through regular blood tests and radiology imaging tests.