Radioembolization is the injection of very small sized spheres (microspheres) containing radioactive material directly into cancer tissue through cancer vessels. Radioembolization, which is applied for the treatment of different cancer cases that have metastasized to the liver, as well as existing cancer in the liver tissue, is also known as microsphere therapy. Radioembolization, which is mostly preferred in liver cancer cases where there is no surgical treatment option, can also be applied to reduce the size of the tumor before surgery.
What is Radioembolization?
Unlike systemic cancer treatments, radioembolization directly affects cancerous cells. It does not harm healthy cells and tissues.
Microspheres containing radioactive material in very small sizes are used in radioembolization treatment. Microspheres reach the cancerous tissue with the help of the circulatory system and emit radioactive energy in the area where the cancerous tissue is, and destroy the tumor, which is the mass formed by cancerous cells. The procedure is performed with the technique defined as angiography.
The purpose of the radioembolization procedure, in which 70% to 80% of the patients respond positively, is to improve the quality of life and prolong the life span of patients with liver cancer or liver metastases.
Which Method is Radioembolization Performed?
Radioembolization can be defined as the process of injecting microspheres containing radioactive material into the artery in the region by entering the vein that feeds the liver tumor, mostly from the groin, with the angiography procedure. Microspheres contain Y-90 radionuclide, or in other words Yttrium-90, a radioactive substance. The procedure, which is performed by releasing a large number of microspheres into the vein feeding the liver, is an effective method in the treatment of liver cancer with low side effects.
By injecting the microspheres into the hepatic artery that feeds the liver, the radioactive material reaches the liver tumor through the hepatic vessels and settles in the smaller vessels that are the tumors.
Microspheres destroy cancer cells by emitting radioactive energy to the cancerous tissue. Meanwhile, its effect on healthy tissue is minimal. After the destruction of cancer cells and therefore tumor tissue in the area, the microspheres are irradiated for several weeks. The ion continues to spread and becomes ineffective after a while.
How is Radioembolization Treatment Planning Made?
The decision of radioembolization treatment is made with a multidisciplinary approach such as oncology, nuclear medicine, radiology, general surgery, gastroenterology and pathology. All department physicians take part in patient selection, treatment planning, patient follow-up and evaluation of treatment.
Angiographic procedures performed before starting the treatment are performed by an interventional radiologist. The nuclear medicine specialist is responsible for adjusting the dose of the radioactive substance to be administered to the patient and evaluating the intervention after the treatment.
Radioembolization application is carried out by interventional radiologists and nuclear medicine specialists. In some cases, other types of therapy are discontinued before radioembolization therapy. The oncologist decides to abandon other treatment options.
Before the radioembolization procedure, the patient's condition and suitability for treatment are evaluated by the cancer council. If the patient is found suitable for treatment, first of all, blood tests are performed. Radioembolization treatment planning begins with angiogram accompanied by CT (Computerized tomography).
Thus, all of the liver vessels of the person are displayed and mapping is made. Arteries feeding the tumor are identified. If it is determined that the artery feeding the liver goes to other organs such as the stomach or intestines, spirals are attached to these vessels. Thus, these vessels are blocked and other organs are prevented from being damaged.
Then, a low dose of radioactive material is administered through the artery feeding the tumor and imaging is performed. Thanks to this procedure, the physician determines how long the radioactive material is retained by the tumor and whether it reaches healthy tissues. Determination of the amount of passage to the lung is also done during this procedure.
During the planning of radioembolization treatment, if the radioactive substance reaches the tumor tissue and does not pass in a dose that will damage the lungs, treatment is started. At this stage, the physician of the nuclear medicine department determines the actual dose to be given to the patient for treatment and microspheres are prepared.
How is Radioembolization Treatment Applied?
- Follow the radioembolization planning process. Treatment is started within 15 days at the most.
- Painkillers and sedative drugs are given to relax the person.
- A very small incision is then made in the inguinal region for catheter placement.
- The catheter is directed from the artery in the inguinal region, defined as the femoral artery, to the hepatic artery in the liver region.
- Microspheres containing radioactive material are injected into the cancerous tissue by being injected into the blood circulation through the catheter placed in the artery feeding the tumor. .
- The microspheres settle into the thin vessels feeding the tumor and the radioactivity is released to the region at the dose determined by the nuclear medicine specialist in advance.
- The radioactive substance in the microspheres has an extremely limited effect on the healthy liver tissue around the tumor tissue. Therefore, it can be said that radioembolization therapy is applied completely target-oriented.
What Should Be Considered After Radioembolization Application?
After the application of radioembolization treatment, the patient is kept in the hospital for one night under observation and is discharged the next day of the procedure.
Radioembolization process typically takes 1 to 1.5 hours. A visit to the outpatient clinic is planned 2 weeks after the treatment and the patient's controls are made.
In case the physician deems it necessary, CT, MR and / or PET scanning as well as other laboratory tests are performed 1 month after the radioembolization treatment.
In the radioembolization application, the treatment is applied to only one lobe of the liver at a time. Therefore, if the other lobe of the liver needs to be treated, re-planning is done. Radioembolization steps to be applied for the other lobe of the liver are the same as the previous one.
What are the Side Effects of Radioembolization Treatment?
The drugs given before the radioembolization procedure for the treatment of cancer cases that metastasize to the liver or liver, The procedure itself is usually painless, although some pain may be felt.
Flu-like side effects such as nausea, vomiting, low-grade fever and fatigue may occur after radioembolization treatment. These complaints disappear completely within a week with supportive treatment. l Within 1-2 days after the treatment, the patient can return to his daily activities.
In rare cases where radioembolization is applied, more serious side effects can be seen. Preliminary evaluation, patient selection and planning steps should be done carefully in order to reduce such side effects. Since there is no definitive treatment option in advanced cases, radioembolization therapy has an extremely important place for the destruction of the tumor. The advantages of radioembolization therapy can be listed as follows:
- It increases the patient's life expectancy and treatment in cases that cannot be treated with surgical methods.
- The existing tumor in the liver is reduced by radioembolization for surgical treatment or liver transplantation.
- As the treatment is targeted, the dose of radiation applied to the person can be safely increased to eliminate the tumor.
- The incision made during the treatment is extremely small.
- When the procedure is required It can be repeated.
- Compared to systemic cancer treatments, its side effects are extremely low.
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