Concept of SIRT:

To selectively target a very high radiation dose to all tumors within the liver

while at the same time

Maintaining a low radiation dose  to the normal liver tissue

• SIR-Spheres ® is a new implantable radiotherapeutic device used to deliver Selective Internal Radiation Therapy or SIRT – approved as a "sealed source"
• SIR-Spheres ® are tiny resin microspheres (average size 32 microns) bound to yttrium-90, a pure beta emitter with a 2.5 day half life and an effective range in tissue of 2.5 mm. 94% of radiation dose delivered within 11 days
• SIR-Spheres ® provide targeted radiation with an average dose of 280-380 Gy to the tumor, while subjecting the normal liver to less than 80 Gy. This dose is much higher than can be achieved with external beam radiation.

• Approximately 20-40 million spheres are delivered using a micro-catheter that is well advanced into the arterial system.
• The administration procedure is performed as an outpatient procedure. The patient can resume chemotherapy 4 weeks post treatment with SIRT.
• SIRT administration requires a coordinated multi-disciplinary team that includes:
  • Interventional Radiology
  • Radiation, Medical, Surgical Oncology
  • Nuclear Medicine, Radiochemist, Physicist, RSO
  • A designated program coordinator
• SIR-Spheres ® were approved by the FDA in March 2002 for Metastatic Colorectal Cancer Patients
• Under the terms of the Medicare Prescription Drug Improvement and Modernization Act of 2003 Medicare reimburses the hospital at 100% cost to charge ratio for the outpatient treatment
• Currently there are 60 US treatment centers
• Approximately 1,500 patients have been treated in the USA and several thousand worldwide.