Patients: About TheraSphere®

TheraSphere® (radioembolization) is a low toxicity, targeted liver cancer therapy that consists of millions of tiny glass microspheres containing radioactive yttrium-90. The glass radioactive microspheres (a mean diameter of 20-30 micrometers – about a third of a width of a human hair) are delivered directly to the liver tumors.

In the US, TheraSphere® is used to treat patients with unresectable hepatocellular carcinoma (HCC), the most common form of primary liver cancer, and can be used as a bridge to surgery or transplantation in these patients. It is also indicated for the treatment of HCC patients with portal vein thrombosis (PVT). Patients will typically receive 1 - 2 treatments over their lifetime.

Your doctor injects TheraSphere® into the hepatic artery of your liver through a small flexible tube known as a catheter. The tiny radioactive glass microspheres flow directly into the liver tumor via its own blood vessels and become permanently lodged in the small blood vessels of the tumor. The radiation destroys the tumor cells from within the tumor, with minimal impact to the surrounding healthy liver tissue. The radioactive microspheres will continue to emit radiation over the course of several weeks after TheraSphere® treatment and radiation levels will decrease to insignificant levels. TheraSphere® treatment is commonly referred to as transarterial radioembolization (TARE) or selective internal radiation therapy (SIRT).

TheraSphere® treatment is typically an outpatient procedure that does not require hospitalization. It is well tolerated by patients, with side-effects that are normally milder than with many other liver cancer treatments. Because the procedure is directed to the liver tumor, there is minimal impact to non-targeted tissue. After treatment, most TheraSphere® patients are eligible for further therapeutic options because the procedure does not block the vessels of the liver.

TheraSphere® treatment has some common side effects, including mild to moderate fatigue, pain and nausea and may occur throughout the first week after treatment. Physicians describe these symptoms as similar to those of the common flu. Some patients may experience loss of appetite and temporary changes in liver blood tests.

The following rare but more severe side effects are possible:

The introduction of microspheres into the vasculature of the stomach, duodenum or other organs of the gastrointestinal tract may cause chronic pain, ulceration and bleeding. Microsphere shunting to the lungs may cause edema and fibrosis that may not be reversible. The use of this product leads to irradiation of both tumorous and normal liver tissue. As a result, patients with diseases that compromise the functioning of their normal liver tissue or patients with either diffuse tumors or a high tumor burden may be at greater risk of liver function impairment.

Despite the fact that TheraSphere® has a minimal effect on normal (healthy) liver tissue, irradiation of both the tumor and normal tissue will occur. As a result, patients with diseases that alter the normal functioning of the liver, or have diffuse or a high tumor burden, may be at greater risk for liver function impairment following treatment with TheraSphere®.

Non-target radiation caused by microspheres entering into, or moving in close proximity to, the gastrointestinal tract or lungs can lead to rare, yet serious complications such as gastrointestinal ulceration and radiation pneumonitis. For more information, please refer to the TheraSphere® Package Insert. For more information, please refer to the TheraSphere® Package Insert.

TheraSphere® is approved by the U.S Food and Drug Administration (FDA) under a Humanitarian Device Exemption (HDE). HDE approvals are based on demonstrated safety and probable clinical benefit. However, effectiveness of the indication for use has not been established.