Preliminary study of ¹⁸F-FDG PET/CT in the diagnosis of solitary hypermetabolic lesion of bone

objective This study aims to investigate the clinical value of 18F-FDG PET/CT in diagnosing solitary hypermetabolic lesion of the bone.

Methods Twenty-two patients with solitary FDG uptake in the bone were enrolled. Patient diagnosis was confirmed by biopsy or surgery. PET/CT images were analyzed.

Results Of the 22 patients, 5 had primary bone lymphoma and bone eosinophilic granuloma, 4 had plasma cell myeloma and osteosarcoma, and 2 had Ewing's sarcoma and giant cell tumor of the bone. The mean SUV_max of bone lesions is 11.08±06(2.1-32.6). Nineteen lesions had well-distributed FDG uptake. The other three lesions were unevenly distributed. No significant difference in FDG uptake was found between malignant and benign lesions(SUV_max:8.86±40 vs. 12.12±58, respectively; t=-1.241, P=0.231), and among different kinds of bone lesions(F=0.296, df=5, P=0.908). Syn-modality CT images showed that 17 patients have osteolytic changes, 5 of which with sclerosis edge. Some bone lesions presented as "bow tie sign", "oap bubble sign? and lace sign? The other 5 patients, 3 with primary bone lymphoma and 2 with osteosarcoma, presented with ossification changes. Otherwise, soft tissue mass was formulated in 17 patients, and periosteal proliferation developed in 4 patients.

Conclusion Syn-modality CT images should be included in the differential diagnosis of solitary hypermetabolic lesion of the bone.