The decision to give neoadjuvant chemotherapy in patients with localized high-risk soft tissue sarcoma is often based on tumor grade evaluated from biopsies, but biopsies can have the inherent issue of sampling bias. Incorporation of SUVmax and heterogeneity assessed by F-FDG PET/CT could be other crucial components in the effort to tailor treatment to an individual patient, providing valuable parameters to guide the selection of the most appropriate management schedule for an individual. We present 1 representative case describing how FDG PET/CT can assist in clinical management decisions for treatment of malignant solitary fibrous tumor of the pelvis.