Although metabolic imaging with F18-fluorodeoxyglucose positron emission tomography(FDG-PET) is more sensitive than standard size-based criteria(RECIST) at monitoring response to therapy in high-grade soft tissue sarcomas(STS), its limited specificity restricts its utility as a functional bio-marker.
Hypothesis: Imaging proliferation with 18F-fluorodeoxythymidine-positron-emission-tomography(FLT-PET) will provide a more accurate assessment of response in patients with high-grade STS.
1. Evaluate the ability of changes in FLT uptake and size to predict histopathologic response to systemic neoadjuvant therapy.
2. Compare change in FLT uptake with immunohistochemical markers of proliferation, cell-cycle-progression and apoptosis.
3. Correlate changes in FLT uptake, size and histopathology with recurrence and survival.