Current utilities of imaging in grading musculoskeletal soft tissue sarcomas

• Non-invasive grading of soft tissue sarcomas is a desirable goal.
• PET measurements currently correlate most closely with soft tissue sarcoma grade.
• Emerging MRI techniques hold promise for development of better prognosis.
• Molecular imaging probes beyond FDG provide functional tumor biology information.

The care of patients with musculoskeletal malignancies has increasingly become a multidisciplinary function. Radiologists play an important role in many areas of these patients’ care including initial diagnosis, staging, in many cases guiding therapy, and monitoring treatment response. However, the gold standard for the final diagnosis of these diseases remains the histopathologic proof. Intense efforts have been made to develop non-invasive methods of determining the tumor grade, or a surrogate, in order to predict biologic behavior, aid early treatment decisions, and provide prognostic information. Multiple imaging modalities have been employed in this domain—including computed tomography (CT); anatomic magnetic resonance (MR) imaging techniques; functional MR imaging sequences such as dynamic contrast enhancement (DCE), diffusion weighted imaging (DWI), MR spectroscopy (MRS); and positron emission tomography (PET). This article reviews current available literature in this realm and highlights future directions towards the potential of non-invasive imaging in grading of soft tissue sarcomas.