Dual-time points (18)F-FDG PET/CT imaging in detection of bone metastases from hepatocellular carcinoma

Bone scan is a well-established imaging modality in detection of osseous metastasis. However, its sensitivity decreases at evaluating lytic osseous metastasis in such entity as hepatocellular carcinoma (HCC). Increasingly, Fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) with dual-time points imaging is utilized in detection of osseous metastasis from hepatocellular carcinoma. We report a case of HCC presenting with a focal increased activity on bone scan corresponding to left distal humeral fracture seen on an X-ray. Subsequent dual-time points (18)F FDG PET/CT scan demonstrated interval increase in FDG activity involving the left distal humeral fracture, favoring neoplastic, rather than post fracture inflammatory process, later biopsy proven to be metastatic hepatocellular carcinoma. Several other FDG avid lesions were also found with interval increase in FDG activity on delayed images, helping to narrow the differential diagnosis to osseous metastases as a cause.