Caren van Roekel

224 Chapter 8 FIGURE 6. Example of poor redistribution. A. DSA showing parasitized blood supply to several liver tumors (arrow heads) from the right inferior phrenic artery (arrow). B. Coil-embolization of the phrenic artery. C. Cone-beam CT of the right phrenic artery shows enhancement of tumors in segment VII (prior to coil-embolization). D. Volumes of interest drawn in Simplicit 90 Y software, the liver volume supplied by the phrenic artery segment was delineated using Cone-beam CT data. E. 90 Y-PET/CT after injection of 90 Y-microspheres in the right hepatic artery shows no redistribution to segment VII. In some of the cases, coil-embolization and the injection of microspheres took place on the same day. All other patients had a time interval between coil-embolization and treatment of up to four weeks. In contrast to what we expected, a longer interval between coil-embolization and treatment did not result in a higher success rate. In fact, patients who were embolized and treated on the same day had higher activity ratios, although not statistically significant. It is important to note that all ‘same day patients’ received treatment with 166 Ho microspheres. However, this higher success rate was not found when comparing 166 Ho to 90 Y microspheres.