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

The sensitivity and specificity of a ¹⁸FDG-PET scan may be different according to the histology. The SUV_max and SUV ratio may reflect the tumor's aggressive behavior.

To describe the characteristics of PET/CT scans, including the maximum standard uptake values (SUV_max), 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).

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 ¹⁸F-FDG PET/CT scans for each patient were searched using the hospital's intranet. The SUV_max 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 SUV_max of the primary tumor and the SUV_liver.

The most common malignancy was SNAC (32%), followed by SNUC (24%), ONB (14%), ACC (10%), SMM (10%), and SNEC (10%). The SUV_max and SUV ratio values were significantly different between tumor types (p = 0.002 and 0.012, respectively). SNUC had the highest mean SUV_max (14.2), followed by SNAC (9.9). A similar mean SUV_max was observed for SMM, ONB, and ACC (∼ 7.0). SNEC up-takes the least ¹⁸FDG among these six tumor types (mean SUV_max= 4.7).