%0 Journal Article %T The Role of Fluorine-18-fluorodeoxyglucose Positron Emission Tomography in Assessing the Response to Neoadjuvant Treatment in Patients with Osteosarcoma %A Carmelo Caldarella %A Marco Salsano %A Maria Antonietta Isgr¨° %A Giorgio Treglia %J International Journal of Molecular Imaging %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/870301 %X Aim. The objective of this study is to systematically review the role of positron emission tomography (PET) and PET/computed tomography (PET/CT) with fluorine-18-fluorodeoxyglucose (FDG) in assessing the response to neoadjuvant treatment in patients with osteosarcoma (OS). Methods. A comprehensive literature search of published studies through March 2012 in PubMed/MEDLINE, Embase, and Scopus databases regarding whole-body FDG-PET and FDG-PET/CT in patients with OS was performed. Results. Twenty-two studies have investigated the role of FDG-PET and FDG-PET/CT in the evaluation of response to neoadjuvant treatment with either chemotherapy or radiation therapy in patients with OS. The main findings of these studies are presented. Conclusion. FDG-PET or PET/CT seems to be sensitive and reliable diagnostic tools in the assessment of metabolic response to treatment in patients with OS, after baseline PET evaluation has been performed in advance. However, false positive findings due to inflammation in sites of tumoral response should be considered. 1. Introduction Osteosarcoma (OS) is the most common primary malignant bone tumour in children and adolescents, with a peak of incidence at the age of 15¨C19 years [1]. OS is a tumour derived from primitive mesenchymal cells, originated from bone and rarely from soft tissue [2]. Although OS can occur in any bone, it is most common in the metaphyses of long bones: distal femur, proximal tibia, proximal humerus, and around the knee [3¨C5]. OS has a high tendency to metastatic spread: 80% of all metastases arise in the lungs (20% of them at initial diagnosis) but metastases can also develop in bone and rarely in lymph nodes [6¨C9]. The 5-year survival rate for OS patients with metastases is 20% compared to 65% for patients with localised disease [10]. Usually, the treatment scheme for patients with OS is comprised of preoperative chemotherapy, surgical removal of all detectable tumour sites, and/or local treatment, followed by postoperative chemotherapy. The prognosis for patients with metastatic disease or recurrent disease remains poor [11, 12]. In order to correctly evaluate patients with OS in staging and restaging, a variety of diagnostic imaging modalities may be used, such as radiography, computed tomography (CT), magnetic resonance imaging (MRI), and traditional nuclear medicine techniques (bone scintigraphy). Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) has been successfully used to evaluate different malignant tumours, such as musculoskeletal tumours [13]. Tumour cells have a metabolic %U http://www.hindawi.com/journals/ijmi/2012/870301/