Intense accumulation of 18F-FDG, not enhancement on MRI, helps to guide the surgical biopsy accurately in soft tissue tumors.

Soft tissue sarcomas are a highly heterogeneous group of malignancies that arise from mesenchymal tissues. Grading of soft tissue sarcomas is an important prerequisite for the choice of therapy and estimation of prognosis. However, incisional biopsy of huge soft tissue sarcoma lesions frequently fails to provide an accurate diagnosis when there is a benign component, cystic changes and/or necrosis. MRI is helpful in evaluating the extent of the sarcoma lesion, vascularization, invasiveness and integrity of surrounding tissue, but definitive differentiation of benignity and malignancy is not possible with it. In this study, positron emission tomography using [(18)F]-2-fluoro-2-deoxy-D-glucose successfully guided surgeons to identify the most hypermetabolic and, therefore, the most suitable biopsy sites of huge soft tissue sarcoma.