Yttrium-90 Microsphere Therapy
What is Yttrium-90 Microsphere Therapy? How does it work?
Theranostics is a recently developing field of the medicine. This approach takes body images using a tumor-specific agent to locate the tumor and its metastasis and their potential future locations and it also uses a specific agent with pre-determined therapeutic efficiency for the diseased tissue. This approach enables switching from traditional medicine to contemporary personalized medical procedures.
Regarding liver cancers, 99mTc- MAA liver perfusion scan allows pre-treatment trial, helps us plan the optimal dose of treatment and detects leakages into lungs and gastrointestinal system with high sensitivity. On the other hand, tumor tissues can be treated with a targeted therapy approach with Yttrium-90 (Y-90) microsphere. This is a rather new and successful method of theranostic procedures.
If treatment uses the hepatic artery, we have an advantage, as the liver is supplied with blood by two blood vessels. This anatomic advantage allowed administration of anti-cancer medications through the hepatic artery for over 30 years. Y-90 microsphere therapy, also called Transarterial Radioembolization (TARE), is an effective treatment for both primary and metastatic cancers of the liver and it may be used for better survival and in order to decrease the burden upon suggestion by a primary physician in patients for whom surgery or regional therapies are not viable.
Y-90 emits beta radiation, which leads to cell death and tumor necrosis when it reaches the tumor region. Y-90 isotope advances in tissues by approximately 1 cm and thus, restricts radiation exposure of neighboring healthy hepatic tissues within this short range. In addition, this short-range beta radiation makes the patient safer for medical personnel and family members of the patient.
Who are Eligible for Yttrium-90 Microsphere Therapy?
Y-90 microsphere therapy is performed for primary or metastatic liver cancers that cannot be removed with conventional surgery.
Is Yttrium-90 Microsphere Therapy Safe?
Y-90 microsphere therapy is a safe treatment that is typically well tolerated.
Since Y-90 emits pure beta particles and does not produce any gamma radiation, isolation of the patient and any special radioprotective measures are not necessary after the treatment.
The most common side-effect of Y-90 microsphere therapy is post-radioembolization syndrome which is characterized by tiredness, nausea, vomiting and/or abdominal pain. Those complaints can be easily treated with analgesic and anti-emetic drugs.
Moreover, there are other quite rarer side-effects which are less likely when the treatment is given by experienced healthcare personnel. These complications can also be prevented with a suitable treatment plan and prophylactic embolization or appropriate catheterization techniques for relevant blood vessels during the preliminary angiogram.
Preparation before Yttrium-90 Microsphere Therapy
Patients who are eligible for Y-90 microsphere therapy are selected by a multidisciplinary tumor council consisting of a General Surgeon, Medical Oncologist, Gastroenterologist, Interventional Radiologist and Nuclear Medicine Specialist.
The first pre-treatment step is evaluation of your general health status and performance, blood test results that indicate your hepatic and renal functions, pathology and surgery reports, past treatments and imaging studies (FDG-PET/CT, MRI, CT etc.).
If you are found eligible for treatment during the preliminary clinical evaluation, an angiogram is performed at the Angiography Unit to evaluate blood vessels of your liver along with liver perfusion scan at the Nuclear Medicine Clinic in order to plan your treatment. Both procedures are completed within one day. Since you need to rest for a few hours following the angiogram to check bleeding, it is advisable to avoid any extra plans on the day of the procedure.
Yttrium-90 Microsphere Therapy
Y-90 microsphere therapy is a multidisciplinary modality which is performed through cooperation of Nuclear Medicine and Interventional Radiology Specialists.
Y-90 microsphere is infused through a catheter that is inserted into the hepatic artery. Microspheres prepared at doses that are specific for you are placed into application kits provided by the manufacturer company and next, the preparation is slowly infused through the catheter by an Interventional Radiologist at Angiography Unit.
Y-90 Microsphere Imaging After Therapy (Bremsstrahlung Scintigraphy and SPECT/CT or Y-90 PET/CT)
Scintigraphic imaging study will be performed to identify uptake locations of Y-90 microspheres, evaluate Y-90 microsphere uptake in non-targeted regions such as lungs and gastrointestinal system and determine the tumor dose at the nuclear medicine clinic.
Y-90 microsphere therapy is a day procedure. However, it is common that our patients have additional health problems. Therefore, it is helpful to follow-up the patients at inpatient settings for a night. If it is deemed necessary on the day of treatment, analgesic and antiemetic drugs, proton pump inhibitors and steroids can be administered for prophylaxis.
A Nuclear Medicine Specialist will schedule an appointment for follow-up examination. Regarding this appointment, please do not forget to bring your blood test reports with you.