Selective Internal Radiation Therapy with SIR-Spheres® Y-90 resin microspheres is typically a 2-stage process. It requires the involvement of a multi-disciplinary team consisting of representatives from most, if not all of the following Specialities: Medical Oncology, Surgical Oncology, Gastroenterology / Hepatology, Nuclear Medicine, Interventional Radiology and Radiation Safety.
During the initial 'work-up' procedure, the hepatic artery vasculature is accessed via a transfemoral catheter to identify tumor feeding vessels. The gastroduodenal artery, right gastric artery and possibly other vessels which might lead to non-target delivery into the gastroduodenal tract may be occluded prophylactically. Subsequently, 99mTechnetium-MAA (Macro Aggregated Albumin) is injected into the catheter, from the same position as is intended for the administration of the SIR-Spheres Y-90 resin microspheres. A Nuclear Medicine scan then determines the amount of arteriovenous shunting into the lung (lung shunting) and identifies any non-target flow. The whole work-up takes approximately 2-3 hours allowing the patient to go home the same day.
One to three weeks later, SIR-Spheres Y-90 resin microspheres are delivered via a transfemoral catheter. Before the administration commences, the tumor blood supply is reassessed and additional vessels occluded if necessary. The whole procedure takes approximately 1 hour and the patient remains under observation for a few hours afterwards. In most cases - depending on local regulations - the patient can go home the same day. It is recommended that a SPECT scan of the upper abdomen is performed within 24 hours following implantation of SIR-Spheres Y-90 resin microspheres. The SPECT scan will detect the Bremsstrahlung radiation from the yttrium-90 SPECT scan to confirm the placement of the microspheres in the liver.
Selective Internal Radiation Therapy with SIR-Spheres Y-90 resin microspheres may be either a single treatment for the whole liver or two separate lobar treatments.
Post-treatment follow-up includes blood tests (liver function) and CT or PET scans.