Exploration of the threshold SUV for diagnosis of malignancy using 18 F-FBPA PET/CT

Background The goal of the study was to evaluate the diagnostic ability of 18 F-FBPA PET/CT for malignant tumors. Findings from 18 F-FBPA and 18 F-FDG PET/CT were compared with pathological diagnoses in patients with malignant tumors or benign lesions. Methods A total of 82 patients (45 males, 37 females; median age, 63 years; age range, 20–89 years) with various types of malignant tumors or benign lesions, such as inflammation and granulomas, were examined by 18 F-FDG and 18 F-FBPA PET/CT. Tumor uptake of FDG or FBPA was quantified using the maximum standardized uptake value (SUVmax). The final diagnosis was confirmed by cytopathology or histopathological findings of the specimen after biopsy or surgery. A ROC curve was constructed from the SUVmax values of each PET image, and the area under the curve (AUC) and cutoff values were calculated. Results The SUVmax for 18 F-FDG PET/CT did not differ significantly for malignant tumors and benign lesions (10.9 ± 6.3 vs. 9.1 ± 2.7 P = 0.62), whereas SUVmax for 18 F-FBPA PET/CT was significantly higher for malignant tumors (5.1 ± 3.0 vs. 2.9 ± 0.6, P < 0.001). The best SUVmax cutoffs for distinguishing malignant tumors from benign lesions were 11.16 for 18 F-FDG PET/CT (sensitivity 0.909, specificity 0.390) and 3.24 for 18 F-FBPA PET/CT (sensitivity 0.818, specificity 0.753). ROC analysis showed significantly different AUC values for 18 F-FDG and 18 F-FBPA PET/CT (0.547 vs. 0.834, p < 0.001). Conclusion 18 F-FBPA PET/CT showed superior diagnostic ability over 18 F-FDG PET/CT in differential diagnosis of malignant tumors and benign lesions. The results of this study suggest that 18 F-FBPA PET/CT diagnosis may reduce false-positive 18 F-FDG PET/CT diagnoses.