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

Background: The goal of the study was to evaluate the diagnostic ability of ¹⁸F-FBPA PET/CT for malignant tumors. Findings from ¹⁸F-FBPA and ¹⁸F-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 ¹⁸F-FDG and ¹⁸F-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 ¹⁸F-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 ¹⁸F-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 ¹⁸F-FDG PET/CT (sensitivity 0.909, specificity 0.390) and 3.24 for ¹⁸F-FBPA PET/CT (sensitivity 0.818, specificity 0.753). ROC analysis showed significantly different AUC values for ¹⁸F-FDG and ¹⁸F-FBPA PET/CT (0.547 vs. 0.834, p < 0.001).

Conclusion: ¹⁸F-FBPA PET/CT showed superior diagnostic ability over ¹⁸F-FDG PET/CT in differential diagnosis of malignant tumors and benign lesions. The results of this study suggest that ¹⁸F-FBPA PET/CT diagnosis may reduce false-positive ¹⁸F-FDG PET/CT diagnoses.