Clinical contribution of f-18 FDG pet/ct in pediatric patients with bone and soft tissue sarcoma

Bone and soft tissue sarcomas seen in the pediatric age group present with similar symptoms but different etiological factors, and the treatment of each diagnosis can be seriously different although it includes similar modalities. In this heterogeneous disease group, the role of F-18 FDG PET/CT imaging in clinical practice and its contribution to disease management may differ from each other. The number of studies indicating that SUVmax, SUVmean, MTV and TLG parameters of the primary tumor obtained in PET/CT examination can be used as prognostic markers are rapidly increasing. In this direction; in our study, we aimed to retrospectively investigate the prognostic significance of staging F-18 FDG PET/CT findings and metabolic parameters of the primary tumor. Sixty three patients aged between 0-18 who were diagnosed with bone or soft tissue sarcoma had staging F-18 FDG PET/CT examination and had at least 9 months of follow-up data were included in our study and they were evaluated separately under 4 groups according to histopathological diagnosis as osteosarcoma, Ewing sarcoma, rhabdomyosarcoma and non-rhabdomyosarcoma soft tissue sarcoma. The effects of quantitative parameters and metastatic status obtained from staging images on progression-free and overall survival were investigated. Kaplan Meier survival analysis and univariate Cox regression analysis were used for survival analysis. The relationship between quantitative parameters and metastatic status, progression and death by non-parametric Mann Whitney U test; The relationship between metastatic status, progression and death was investigated with Pearson Chi-Square and Fisher exact test. In our study, in the pediatric group we found that high SUVmax, SUVmean, MTV and TLG values of the primary tumor obtained from staging F-18 FDG PET/CT imaging in patients diagnosed with bone and soft tissue sarcoma were associated with an increase in the frequency of distant metastases. It was found that high MTV and TLG values were associated with an increase in the frequency of death in patients with soft tissue sarcoma, and an increase in both progression and mortality in patients with bone sarcoma. In addition, MTV value was found to affect survival time in Ewing sarcoma and non-rhabdomyosarcoma soft tissue sarcomas. According to these data; it has been concluded that the MTV and TLG values of the primary tumor can be used as a prognostic marker in the staging F-18 FDG PET/CT examination and may contribute to the treatment/follow-up management of the disease. Prospective studies including larger numbers of patients are needed to confirm these results.