Philip Borg MD, FRCR, Presenter: Nothing to Disclose

Jon Kingsley Bell MBChB, FRCR, Abstract Co-Author: Nothing to Disclose

Steve Philip Jeans, Abstract Co-Author: Nothing to Disclose

Jill Philip Tipping, Abstract Co-Author: Nothing to Disclose

Amarjot Chander, Abstract Co-Author: Nothing to Disclose

Damian P. G. Mullan FFR(RCSI), FRCR, Abstract Co-Author: Nothing to Disclose

Prakash Manoharan MRCP, FRCR, Abstract Co-Author: Nothing to Disclose

Jeremy Andrew Liste Lawrance MBChB, Abstract Co-Author: Nothing to Disclose

To evaluate the efficacy of delivery of microsphere delivery during Selective Internal Radiation Therapy (SIRT) using SIR-Spheres® to segments of the liver that have been coil embolised. Embolisation of the left hepatic artery and or its branches to prevent extra-hepatic distribution of Yttrium90 (Y90) microspheres is often performed in selective internal radiation therapy (SIRT). This has a potential to under treat portions of the liver.

158 SIRT cases over an 8 year period were reviewed. Cases with unfavorable anatomy underwent coil occlusion of part or all of the left or right hepatic arteries to ensure safe whole liver therapy. Using Xeleris® imaging software analysis was made on the planar gamma and bremsstrahlung imaging. Regions of interest (ROI) for the right and left lobes of the liver were drawn and a geometric mean ratio of right:left (R:L) post administration of Tc99mMAA and post Y90 microspheres. ROIs were adjusted for background scatter. R:L liver lobe ratios in patients who had partial embolisation of the hepatic artery compared to R:L liver lobe with no embolisation.  

Post Tc99mMAA Non embolised patients R:L ratio mean = 8.8 Embolised patients R:L ratio mean = 20.5 Post Y90 microspheres Non embolised patients R:L ratio mean = 5.6 Embolised patients R:L ratio mean = 8.9  

After injection of Y90 patients with partial hepatic artery embolisation had a larger R:L lobe ratio when compared to those not embolised. The same was true after injection of Tc99mMAA but to a greater extent. This difference in ratios, with better uptake in the left lobe after injection of Y90 can be explained by the development of intrahepatic collateral flow channels in the 2-3 week period between the Tc99mMAA scan immediately post coil embolisation and the Y90 scan. Laminar flow also affects distribution of Y90 and Tc99mMAA. These preliminary results from analysing planar imaging of 23 patients will be correlated with SPECT CT on a larger number of patients.

Although there is a significant decrease in treatment to the embolised segments, there is likely development of intracollateral flow channels to embolised segments, increasing delivery of radiospheres after partial coil embolisation hepatic arteries. This is an acceptable compromise to ensure safe delivery of Y90 microspheres without extrahepatic distribution. 

Borg, P, Bell, J, Jeans, S, Tipping, J, Chander, A, Mullan, D, Manoharan, P, Lawrance, J, Vascular Redistribution Following Partial Hepatic Artery Embolisation for SIRT— Efficacy of Delivery of Y90 Microspheres to Embolised Liver Segments.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007347.html