Abstract

Imaging primary musculoskeletal tumors: role of 18F-FDG-PET/CT

Author(s): Klaus Strobel, Dorothee R Fischer, Katrin DM Stumpe and Gustav K von Schulthess

Sarcomas are rare and represent approximately 1% of malignant tumors. Symptoms may be pain, palpable mass or pathologic fractures. Early diagnosis of sarcomas is essential, because prognosis and therapeutic options are much better in lower tumor stages than in higher tumor stages. However, the diagnosis of soft-tissue sarcomas or bone sarcomas is often delayed owing to the lack of specific clinical symptoms and misinterpretation of radiological findings. Optimal management of sarcomas depends on the site, grade and accurate staging of the tumor when first diagnosed. The metastatic spread of sarcomas is mainly hematogenous to the lungs, although lymphatic spread may occur. Traditional diagnostic imaging methods for the evaluation of musculoskeletal tumors include ultrasound, CT, MRI and bone scintigraphy. PET and PET/CT is a relatively new imaging technique that enables in vivo characterization of tumor metabolism. 18F-2-deoxy-2-fluoro-glucose (FDG) is the ‘work horse’ tracer of tumor imaging with PET. Broadly speaking it identifies tumors that are aggressive, while low-grade tumors frequently do not accumulate FDG. In this article, we review our own experience and the literature regarding FDG‑PET/CT imaging of musculoskeletal tumors with special focus on sarcomas.