Y-90 Sir-Sphere treatment of liver cancer and alternative imaging methods

2706 Objectives Selective Internal Radiation Therapy (SIRT) is a new and promising therapy that has changed the options and outcomes of treatment compared to conventional radiotherapy. SIR-Spheres are microscopic Y-90 radioactive spheres used to deliver SIRT to the liver. It differs from traditional systemic therapies since the radiation is delivered directly to the tumor. There are, however, different techniques to assess what portion of the liver is being treated. The current imaging guidelines for confirming the placement of the microspheres is a SPECT scan detecting the Bremsstrahlung radiation from the Y-90 microspheres. Methods The package insert was reviewed for indications, contraindications, patient selection, radiation safety, dose calculation, and imaging guidelines. Fifteen patient cases from Saint Louis University Hospital were retrospectively analyzed by a physician to determine the differences in Bremsstrahlung SPECT imaging versus PET/CT. Results The manufacturer Sirtex recommends performing a Bremsstrahlung SPECT scan of the upper abdomen after treatment. However, after consultation with a physician, we believe performing a PET/CT scan has the potential to allow for increased delineation and quantitative analysis of the actual delivered tumor dose. This has successfully been implemented at our center. Conclusions SIRT with Y-90 SIR-Spheres is a new addition to the treatment of liver cancer and shows promising results of improving the quality of life including the possibility of a liver transplant in someone previously ineligible. An encouraging alternative to confirm placement of the microspheres is performing a PET/CT scan to increased image resolution and potentially increasing quantitative capabilities providing a more accurate estimation of dose received and may pave the way for more personalized dosimetry.