Selective internal radiation therapy (SIRT), also known as radioembolization, is a targeted therapy for treating liver tumors. SIRT uses the fact that the source of blood supply to a liver tumor is different from that to healthy liver tissue. As much as 99% of the blood supply to a liver tumor comes from the liver artery (also known as hepatic artery); whereas 80% of blood supply to the healthy liver tissue comes from the portal vein. During the SIRT procedure, millions of tiny radioactive beads, or microspheres, are administered directly into (branches of) the hepatic artery. Due to the preferential blood flow towards the liver tumor(s) and the specific size of the microspheres, they accumulate in and around the liver tumor(s). Tumor cells are killed by the locally delivered radiation dose. With SIRT, a relative high radiation dose is delivered to the tumor(s) whereas the healthy liver tissue receives a much lower dose.

QuiremSpheres® consists of tiny biodegradable polymer beads, called microspheres, that contain radioactive holmium-166. The development of holmium-166 microspheres is based on 20 years of extensive pre-clinical and clinical research data, proving its safety and efficacy. Holmium-166 microspheres were developed out of clinical need by a group of expert physicians and scientists at the Department of Radiology and Nuclear Medicine of the University Medical Center Utrecht (UMCU). The clinical team wanted to develop a new generation microsphere that could easily and accurately be visualized and quantified with SPECT and MRI.  They succeeded and within the UMCU alone already more than 150 patients have been successfully treated.

QuiremSpheres® received European regulatory approval (CE-mark) in 2015 for treating liver tumors that cannot be surgically removed. These tumors can either originate from liver (also known as primary liver cancer) or spread to the liver from other parts of the body (also known as secondary liver cancer or metastases). Many patients have since successfully been treated in certified QuiremSpheres® hospitals across Europe.

QuiremSpheres as a SIRT treatment option offers unique advantages thanks to the distinct features of holmium-166. Not only QuiremSpheres is efficient at killing cancer cells, these tiny microspheres can also be visualized shortly after the treatment with multiple imaging modalities (i.e. SPECT and MRI). These post-treatment images provide important insights to your doctor. For instance, these images will allow your doctor to assess treatment efficiency by determining whether all tumors have been efficiently targeted and formulate the optimal follow-up strategy.

Recent studies show that absorbed dose received by the tumor(s) after SIRT is directly correlated with clinical outcome and overall survival after the procedure. It is therefore of great importance to asses prior to SIRT procedure if sufficient radiation dose to the tumor(s) can be achieved, for the treatment to be effective. Our unique SIRT simulation product, called QuiremScout®, allows for a safe and accurate assessment of the biodistribution of intraarterially injected microspheres prior to the actual SIRT treatment. This simulation step helps your physician to make an informed decision whether SIRT is indeed right for you and also how to optimize the treatment.

Due to its proven effectiveness, SIRT is recommended for treatment of unresectable primary and secondary liver cancer in various medical guidelines, such as the NCCN guidelines, EASL-EORTC and ESMO guidelines. Within these guidelines SIRT is recommended to be used in a salvage setting, in other words, if all other treatment options have been used but do not induce a response or cannot be endured. 

QuiremSpheres is suitable for patients with liver tumors where the liver is either the only site of disease or the liver is the major site of disease as QuiremSpheres has no effect on tumors outside the liver. Your doctor considers several factors to decide whether you are suitable for a treatment with QuiremSpheres. One of the most important factors is whether your liver is healthy enough to receive the treatment. This assessment can usually be achieved by a simple blood test. Other factors can be your medical history, relevant therapies you have received in the past and the blood flow in your liver (to minimize side effects). You can ask your doctor about the tests that are performed prior to your QuiremSpheres treatment

The typical level of side effects after SIRT are mild to moderate. Common side effects are fatigue, nausea, vomiting, abdominal pain, and fever. These side effects are transient. After the SIRT procedure, your doctor will monitor your health status and liver function.

The administration of QuiremSpheres® can only be performed by trained and certified healthcare professionals (HCPs). In most centers, performing the procedure is a collaborative effort between the nuclear medicine physician and interventional radiologists. QuiremSpheres® treatment is typically an outpatient procedure, meaning you do not need to be hospitalized. Before the treatment, you may be given pain medication and a sedative to help you relax. You are able to communicate with your treating physician and the team throughout the procedure

Here is a video demonstrating the procedure.

• • Your treating physician injects QuiremSpheres® into the liver artery through a small flexible tube, also known as a catheter. Access to the liver artery is usually obtained by creating a small puncture into the artery from either around the femur (near the groin) or the wrist. The catheter is then guided through the artery into the liver under x-ray imaging. A numbing medication will be applied at the site beforehand.
  • The tiny QuiremSpheres® microspheres are administered through this catheter and flow directly into the liver tumor via its own blood vessels and become permanently lodged in the small blood vessels surrounding the tumor.
  • Administration of QuiremSpheres® can be achieved by using the dedicated QuiremSpheres® Administration Kit that is developed together with expert physicians. The kit has been used by all QuiremSpheres® centers and proven to be safe, easy-to-use and efficient.
  • The entire administration procedure takes between 60-90 minutes

After the procedure, the catheter is removed. You are taken to a recovery area in the nuclear medicine department of the hospital where you will typically stay for 4-6 hrs.

QuiremSpheres® patients leaving the hospital are safe to the people around them. By the time of discharge, the field of radiation outside the body is low enough to comply with radiation safety. In most cases, you can return home after 6 hours. For some patients, they may return home after 24 hours depending on the amount of activity received during treatment. Most hospitals provide general instructions for discharge based on recommendations from national/international guidelines. Your doctor will inform you on these specific instructions when you leave the hospital.