SIR-Spheres®: Y-90 resin microspheres
SIR-Spheres® Y-90 resin microspheres are a medical device used in Selective Internal Radiation Therapy (SIRT) for liver tumors. SIR-Spheres Y-90 resin microspheres are a permanent implant and for single use only. The biocompatible resin microspheres containing yttrium-90 have a median diameter of 32.5 microns (range between 20 and 60 microns).
Yttrium-90 is a high-energy beta-emitting isotope with no primary gamma emission. The maximum energy of the beta particles is 2.27MeV with a mean of 0.93MeV. The maximum range of emissions in tissue is 11mm with a mean of 2.5mm. The half-life is 64.1 hours. Following administration, 94% of the radiation is delivered in 11 days.
These properties of the SIR-Spheres Y-90 resin microspheres mean that the microspheres lodge preferentially in the microvasculature surrounding the tumor, maximising tumorcidal effects and minimising the effects on healthy liver parenchyma (for further information see Mode of Action)
Benefits from application of SIR-Spheres® in patients are well documented in the large number of published clinical trials. Especially with the publication of primary endpoint results from the multi – center Randomized Phase III Control Trial SIRFLOX, SIR-Spheres®became the only SIRT supported by Level – 1 evidence.
Selective Internal Radiation Therapy (SIRT), also known as Radioembolisation, is a liver-directed therapy for inoperable liver tumours. SIRT is administered by a specially trained Interventional Radiologist.
A microcatheter is used to deliver millions of radioactive microspheres into the hepatic artery, where they are carried into the arterioles and selectively lodge in the tumour microvasculature (for further information see Mode of Action).
• Increase the time to progression
• Extend overall survival
• Potentially downsize or downstage tumours for liver resection, ablation, or transplantation
• Provide palliation of symptoms
SIRT can be combined with modern chemotherapy or administered as a monotherapy, either during a chemotherapy holiday, in a salvage setting or as an alternative to local chemotherapy.
Radioembolization Procedure Scheme
- Proper patient selection from referring Physicians and/or Tumor boards for work up (for further information concerning patient selection press here http://www.sirtex.com/eu/clinicians/about-sirt/patient-selection/ )
- Patient Work Up procedure under which patient eligibility is verified and treatment details are decided and finalized. (for further information concerning Work Up press here http://www.sirtex.com/eu/clinicians/about-sirt/work-up/ )
- Radioembolization (Implant Procedure) is performed from 1 to 3 weeks after Work Up procedure has been completed (for further information concerning Implant Procedure press here http://www.sirtex.com/eu/clinicians/about-sirt/implant-procedure/ )