We will conduct a prospective trial to verify the validity of indices utilizing TGF-b1, NF-kB, PET/CT, and MRS for predicting response to neoadjuvant chemotherapy in osteosarcoma patients. We assume that changes in plasma TGF-b1 levels, PET/CT and magnetic resonance spectroscopy (MRS) findings during the period of neoadjuvant chemotherapy as well as the initial nuclear NF-kB expression status of tumor biopsy specimen either alone or in combination may predict a chemotherapeutic response determined by histopathologic necrosis fractions of tumors removed. To test this, we will obtain TGF-b1 levels, PET/CT and MRS findings at diagnosis and at follow-up (after first and second/third chemotherapy cycle). Tumor will then be removed. Chemotherapy regimen comprised of various combination of cisplatin, adriamycin, and high-dose methotrexate, ifosfamide, and etoposide. Indices derived from TGF-b1, PET/CT, MRS predicting greater than 90% necrosis fractions will be sought utilizing statistical methods.