AbstractA 76-year-old man with hepatocellular carcinoma was referred for liver radioembolization. Given a prior left hemihepatectomy, it was clinically important to consider potentially irradiated healthy liver at planning. Thus, at the SPECT/CT imaging of the scout dose166Ho-microparticles before injected superselectively in the right hepatic artery,99mTc-mebrofenin was injected intravenously, and functional volumetry SPECT was performed simultaneously. Based on the 2 image sets, the nonirradiated healthy liver was calculated as 1589 mL (functional liver reserve of 85.5% on99mTc-mebrofenin SPECT). Posttreatment dosimetry calculations showed optimal normal tissue and tumor absorbed doses, and the patient is clinically well after 3 months.