The Role of 18F-FDG-PET/CT in Pediatric Sarcoma.

Considerable debate remains regarding how best to incorporate 18F-FDG-PET/CT into clinical practice for pediatric sarcomas. Although there is a clear role for 18F-FDG-PET/CT in staging pediatric sarcoma, the value of 18F-FDG-PET/CT in prognostication for pediatric sarcomas remains unclear. In osteosarcoma, Ewing sarcoma, and rhabdomyosarcoma, 18F-FDG-PET/CT may be most useful in the identification of skeletal metastases, where the literature consistently suggests that it has improved sensitivity and specificity as compared to bone scintigraphy. The role of the imaging modality in the identification of pulmonary metastatic disease is less clear. Further controversy exists regarding the use of 18F-FDG-PET/CT in predicting outcome. Several studies, particularly in osteosarcoma, suggest changes in the maximal standardized uptake value (SUVmax) that can predict histologic response following neoadjuvant chemotherapy as well as overall outcome. Conversely, studies are conflicting regarding the use of 18F-FDG-PET/CT as a prognostic tool in Ewing sarcoma and rhabdomyosarcoma. The role of 18F-FDG-PET/CT in pediatric nonrhabdomyosarcoma soft tissue sarcomas is unknown at this time. Although most studies have been small and retrospective, in certain histologic subtypes, there is a clear role for the use of this imaging modality. Additional prospective and larger studies are needed to fully determine how best to incorporate 18F-FDG-PET/CT into treatment regimens for pediatric sarcomas in the future.