Relationship between 18FDG-PET and different types of sinonasal malignancies

Conclusion: The sensitivity and specificity of a (18)FDG-PET scan may be different according to the histology. The SUVmax and SUV ratio may reflect the tumor's aggressive behavior. Objectives: To describe the characteristics of PET/CT scans, including the maximum standard uptake values (SUVmax), at initial diagnosis according to six main types of sinonasal malignancies: sinonasal adenocarcinoma (SNAC), sinonasal undifferentiated carcinoma (SNUC), adenoid cystic carcinoma (ACC), sinonasal malignant melanoma (SMM), olfactory neuroblastoma (ONB), and sinonasal neuroendocrine carcinoma (SNEC). Methods: A chart review of 50 patients who were diagnosed and treated for six sinonasal malignancy types over a period of 6 years was conducted. Any F-18-FDG PET/CT scans for each patient were searched using the hospital's intranet. The SUVmax of the primary sinonasal site was recorded. The liver SUVs were utilized as reference SUVs. The SUV ratio was defined as the ratio of the SUVmax of the primary tumor and the SUVliver. Results: The most common malignancy was SNAC (32%), followed by SNUC (24%), ONB (14%), ACC (10%), SMM (10%), and SNEC (10%). The SUVmax and SUV ratio values were significantly different between tumor types (p=0.002 and 0.012, respectively). SNUC had the highest mean SUVmax (14.2), followed by SNAC (9.9). A similar mean SUVmax was observed for SMM, ONB, and ACC (similar to 7.0). SNEC up-takes the least (18)FDG among these six tumor types (mean SUVmax=4.7).