Abstract
2708a
Objectives Our study aimed to compare the diagnostic value of 18F-NaF positron emission tomography-computed tomography (PET/CT) and 18F-fluorodeoxyglucose (FDG) PET/CT for detection of skull base invasion and osseous metastases in patients with NPC, and then to assess the added value of 18F-NaF PET/CT.
Methods Our study retrospectively analyzed 45 patients with pathologically proven NPC. They all underwent both 18F-NaF PET/CT and 18F-FDG PET/CT within a 7-day interval. Bone metastases were confirmed by follow up using approaches such as enhance-contrast computed tomography (CT) and magnetic resonance image (MRI) and so on. These two examinations were compared using per-patient based analysis and per-lesion based analysis.
Results 18F-NaF PET/CT detected 27 patients with skull base invasion while 18F-FDG PET/CT detected 17 positive patients. 18F-NaF PET/CT and 18F-FDG PET/CT differed significantly in diagnosing skull base invasion (P=0.02) while the difference in specificity was not significant (P=1). Osseous metastases were detected in 26 of 45 patients by at least one examination using 18F-NaF PET/CT and 18F-FDG PET/CT. 18F-NaF PET/CT and 18F-FDG PET/CT detected 208 and 81 bone metastatic lesions, respectively. 18F-NaF PET/CT detected more metastatic lesions than 18F-FDG PET/CT(t=2.45,P=0.18). The sensitivity of 18F-NaF PET/CT in detecting osseous metastases was higher than 18F-FDG PET/CT (P<0.0001). 18F-NaF PET/CT changed 16 of 45 (35.6%) managements made by the 18F-FDG PET/CT.
Conclusions In patients with nasopharyngeal carcinoma, 18F-NaF PET/CT assessed invasion of the skull base better and detected more osseous metastases than 18F-FDG PET/CT. 18F-NaF PET/CT had additional value in improving the management.