False-Positive Bony FDG Accumulations Due to Fractures in a Patient with Lung Cancer: the Value of Integrated Information of PET/CT

Received 4/14/2009; revised 4/23/2009; accepted 4/30/2009. For correspondence and reprints contact: Guang-Uei Hung, M.D., Department of Nuclear Medicine, Chang-Bing Show Chwan Hospital. 6 Lugong Road, Lukang Township, Changhua 500, Taiwan. Tel: (886)4-7813888 ext. 70161, E-mail: [email protected] Fluorine-18-fluorodeoxyglocose (F-FDG) positron emission tomography (PET) or PET/computed tomography (CT) is a powerful modality in the staging, follow-up and therapeutic evaluation of oncologic patients, including lung cancer. However, FDG is not a specific tracer for cancer and false-positive uptake occasionally occurred. Here, we present a 78-year-old male with history of lung cancer underwent F-FDG PET/CT for follow-up. The PET images showed multiple FDG-avid foci in the bony structures, including ribs, distal and proximal portions of right clavicle and L2 vertebra, and were initially considered as bony metastases. But the co-registered CT images showed typical evidences of fractures and history of recent traffic accident with direct impaction to the chest was traced. Follow-up images, including PET/CT and bone scan, revealed complete resolution of the rib lesions. The bony lesions were finally considered as traumatic fractures. The presented case demonstrates the value of the co-registered CT images in PET/CT study not only in attenuation correction and anatomical localization but also morphological characterization of the FDG-avid lesions to avoid falsepositive interpretation due to traumatic fractures.