Yttrium-90 Microspheres Therapy for Liver Cancer
Microspheres are tiny glass or resin spheres that contain the radioisotope Yttrium-90. This radioisotope delivers its radiation over a short range. They are used to treat patients with liver cancer. There are two types of microspheres used: SirSpheres® and Theraspheres®. They are both very similar in the way they work.
The procedure is carried out in two stages, usually one to three weeks apart. Both procedures are carried out in a theatre and are followed by a scan in Nuclear Medicine. The first part is called the “work-up” or pre-therapy appointment. It is usually carried out on an outpatient basis. The second part is the therapy appointment and is always carried out on an inpatient basis, including an overnight stay.
During the work-up stage, a tracer is injected into the liver via the hepatic artery. This is done in theatre. Since these blood vessels supply most of the blood for the liver tumours, the tracer gets stuck in these vessels. This is done in the same way as it will be for the therapy, but the tracer is used for diagnostic purposes only. Once the tracer has been injected, the patient is scanned on a gamma camera in Nuclear Medicine to take pictures of where the tracer has gone. This will show whether a lot of the tracer goes to the lungs. If so, the therapy may not be able to go ahead as the radiation dose to the lung would be too large.
During the therapy stage, the microspheres are injected into the hepatic artery. The Microspheres get stuck in the blood vessels and give a radiation dose to the liver tumours. The patient stays overnight on a ward and is scanned the following day in Nuclear Medicine to confirm that the Microspheres have gone to the intended areas.
Upon discharge patients are issued with a radiation protection advice card. Since the therapy agent is radioactive, some simple precautions may need to be followed.
More detailed information can be found in the Patient Information Leaflet, which can be found by clicking on this link.