ORIGINAL ARTICLES   

Panminerva Medica 2005 September;47(3):187-9

Copyright © 2009 EDIZIONI MINERVA MEDICA

lingua: Inglese

Does 18F-FDG PET/CT play a role in the differential diagnosis of parotid masses

Rubello D. ¹, Nanni C. ², Castellucci P. ², Rampin L. ¹, Farsad M. ², Franchi R. ², Mariani G. ³, Menaldo G. ⁴, Fanti S. ²

¹ PET Unit, Department of Nuclear Medicine S. Maria della Misericordia Hospital, Rovigo, Italy 2 PET Unit, Department of Nuclear Medicine S. Orsola-Malpighi, University of Bologna, Bologna, Italy 3 Regional Center of Nuclear Medicine University of Pisa, Pisa, Italy 4 Department of Otorhinolaryngology S. Maria della Misericordia, Rovigo Hospital, Rovigo, Italy

Aim. The aim of the present study was to assess the accuracy of an hybrid PET/CT scanner in the evaluation of newly diagnosed parotid masses, comparing the results with those reported in the literature with using PET scanners only.
Methods. The potential role of 18F-FDG PET/CT in distinguishing benign from malignant parotid masses in 14 consecutive patients was investigated. All patients were preoperatively evaluated by means of ultrasound (US), US-guided fine needle aspiration (FNA) cytology, computed tomography (CT) scan, magnetic resonance imaging (MRI) and 18F-FDG PET/CT. For To interpreting FDG PET findings, the right to left parotid (R/L) SUV max ratio was calculated in a group of 54 patients without evidence of parotideal disease (mean±SD = 1±0.2; range = 0.8-1.2); considering the R/L SUV max ratio, focal or diffuse uptakes <0.8 or >1.2 were considered as potentially pathological.
Results. Imaging data were compared with surgical and histopathological findings. At FDG PET/CT, 9 false positive cases were found (8 Warthin’s tumours, 1 pleomorphic adenoma), 1 false negative (acinar cell carcinoma), 4 true negative (1 Warthin’s tumour, 1 pleomorphic adenoma, 1 lymph epithelial cyst, 1 parotid inflammation) whereas there was no case of true positive. The global accuracy of FGD PET/CT was rather low = at 29%.
Conclusion. In agreement with other preliminary reports in which the FDG PET without CT fusion imaging was used, in our experience 18F-FDG PET/CT did not prove to play a significant role in differential diagnosis (benign vs malignant) of parotid masses. Further studies collecting larger groups of patients are needed to further elucidate this observation.