Figure 5: Registered axial images of a patient with liver metastatic colorectal cancer. (a) baseline FDG PET-CT shows the target lesion with central necrosis located in segment IV,( b) simulation SPECT-CT image after supraselective 99Tc-MAA administration in the left hepatic artery, indicating that the lateral part of the lesion is not perfused via the left hepatic artery; (c) the post-treatment 90Y PET-CT after supraselective SIRT administered in the left hepatic artery, showing microsphere deposition in the peripherical (non-necrotic) part of the lesion, except for the lateral part, confirming the 99mTc-MAA SPECT-CT finding ; (d) FDG PET-CT image obtained at 6 weeks post SIRT indicating residual (non-treated) disease at the lateral segment of the initial tumor. The medial part of the lesion shows an almost complete metabolic response. Additional local ablative treatment of the residual tumor lesion was needed.