Kato A, et al. - This research was sought to analyze quantitative parameters in ¹⁸F-FDG PET/CT in terms of association with histologic grade and overall survival in patients with angiosarcoma. Researchers retrospectively examined the cases of 16 patients with histologically confirmed angiosarcoma who had undergone pretreatment FDG PET/CT. This study estimated maximum standardized uptake value for the primary tumor (pSUV_max), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) for the whole body, tumor-to-blood ratio (TBR) for the primary tumor, and summed ratios of tumor-to-blood glycolytic activity for all lesions (whole-body TLG ratio). The evidence showed that the high-grade tumors had significantly higher pSUV_max and primary TBR at FDG PET/CT in angiosarcoma. In this study, all quantitative parameters evaluated were found to be significant prognostic factors for overall survival.