Ga-67-positive and F-18 FDG-negative imaging in well-differentiated hepatocellular carcinoma

Hepatocellular carcinomas (HCC) are the fifth most common cancer and are rapidly fatal in almost all cases, with survival generally less than 1 year from diagnosis. F-18 FDG accumulates in tissues where glucose metabolism is enhanced. As HCC differentation varies, well-differentiated and low tumor grades show less activity on PET. Conversely, Ga-67 scintigraphy may be positive in such cases, as the inflammatory process is usually important in HCC. The combination of positive Ga-67 imaging and negative F-18 FDG imaging should indicate well-differentiated or low-grade HCC.