About TheraSphere®:State-of-the-art brachytherapy for unresectable liver cancer
State-of-the-art brachytherapy for unresectable liver cancer
MDS Nordion Inc.
The need for a new treatment
All currently used treatments for unresectable (inoperable) liver cancer that reduce the symptoms of this disease require hospitalization, and usually cause side effects that reduce the quality of life for patients. For example, chemotherapy and chemoembolization often produce nausea, vomiting and hair loss. (For more information on these therapeutic treatment options visit the National Cancer Institute website.)
As a result, there is a need for new treatments that offer the convenience of outpatient therapy and fewer and milder side effects.
Localized internal radiation - Taking advantage of tumour vascularity
TheraSphere® builds upon growing medical knowledge of liver structure and function and previous experience with other types of therapy to offer a new, more convenient treatment option. TheraSphere® also builds on knowledge physicians have gained in recent years with brachytherapy, radioactive implants that are now increasingly used to treat prostate cancer.
Previous attempts to treat liver cancer with radiation from external sources (radiation beam therapy) showed some easing of symptoms, suggesting that liver cancer is sensitive to radiation. But there is a major drawback to external radiation: it cannot be tightly focused on the tumor, but instead, affects a larger area of the body that includes the tumor.
This lack of precise focus exposes healthy areas of the body to radiation and produces unpleasant side effects, including changes to healthy tissue, nausea and vomiting. Therefore, researchers began to develop ways to place radiation directly into the liver, targeted as precisely at the tumors as possible, with the least effect on healthy liver tissue or surrounding organs.
To direct TheraSphere® treatment at tumors in the liver, a physician first makes a small incision in the patient's leg and places a long, flexible plastic tube called a catheter, into the femoral artery, which is the major blood vessel in the leg. Guided by fluoroscopy (an X-ray imaging technique that projects views of the inside of the body onto a screen) the physician then moves the catheter up through the blood vessels to the hepatic artery, which is one of two blood vessels that feeds the liver. The physician guides the catheter into the branch of the hepatic artery that feeds the cancerous tumor in the liver and infuses the TheraSphere® beads through the catheter into the blood that supplies the tumor. This is usually performed in a hospital's radiology suite and patients remain conscious throughout the procedure.
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