False negative F-18 FDG PET/CT in nonsmall cell lung cancer bone metastases.

Abstract

Tc-99m MDP bone scintigraphy is frequently performed for suspected skeletal metastases in lung cancer. F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) has also proved useful for staging nonsmall cell lung cancer, and it offers superior spatial resolution and improved specificity for bone metastases. Although F-18 FDG-PET is superior to Tc-99m MDP bone scintigraphy for the detection of bone metastases, the sensitivity for sclerotic (osteoblastic) metastases by F-18 FDG PET/CT is lower than for lytic metastases. These bone metastases may not be glycolytically active and may be below the requisite tumor mass needed for FDG accumulation. We describe the case of false-negative F-18 FDG PET/CT findings in a 57-year-old woman who demonstrated sclerotic bone metastases from nonsmall cell lung cancer. F-18 fluoride PET demonstrates a similar uptake pattern as Tc-99m MDP.