Bone metastasis: detection by 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/ computed tomography (CT) in lung cancer patients

Objectives: We aimed to evaluate the impact of FDG PET/CT in detecting different types of bone metastasis in patients with lung cancer. Materials and Methods: We retrospectively selected 57 patients (45 male and 12 female; median age: 70 y) with lung cancer (24 adenocarcinoma, 6 SCLC, 12 NSCLC and 15 not disposable) who underwent FDG PET/CT for initial staging (n=16, 28%), restaging (n=32, 56%) and follow-up (n=9, 16%). All images were re-evaluated by a nuclear medicine physician and a radiologist. All site of metastases were registered and confirmed by follow-up imaging or by histological staining. The distribution of bone metastases was determined and described. Results: All patients had a positive FDG PET/CT, in particular 23 had bone metastases and were confirmed in 21 of them by followed CT or magnetic resonance imaging (MRI). Two patients were falsely positive at PET/CT (one for arthritis and one for fractures), three patients had bone marrow involvement (one patient at left 5th rib, one at lumbar spine and one at pelvis). In these latter patients the lesion SUVmax was 3.01, 9.82 and 6.9, respectively. Pathological FDG-uptake was reported in two patients with both osteolytic and osteoblastic lesions, in 12 patients with osteolytic ones and in 4 with osteoblastic metastases. Conclusions: FDG PET/CT is able to detect bone metastases in patients with lung cancer in any phase of disease. The support of CT can address to the anatomical characteristic of bone lesion, being useful for the assessment of treatment.