Unsuspected Metastatic Ovarian Cancer Revealed by 18F-NaF PET/CT Performed to Evaluate Lower-Back Pain.

A 59-year-old woman with back pain underwent an F-NaF PET/CT bone scan. Unexpectedly, multiple foci of increased tracer uptake were present in the abdomen and pelvis, which corresponded to the calcified soft tissue masses. The subsequent F-FDG PET/CT not only confirmed increased FDG activity in these partially calcified mass but also revealed abnormal activity in noncalcified lesions. The pathological examination demonstrated that the patient had ovarian cancer.