(18)F-fluorodeoxy glucose positron emission tomography/computed tomography manifestation and clinical characteristics of primary salivary gland-type lung cancer

Abstract

Objective: To explore the imaging manifestation and clinical characteristics of primary salivary gland-type lung cancer using (18)F-fluorodeoxy glucose ((18)F-FDG) positron emission tomography/computed tomography (PET-CT). Methods: From March 2009 to January 2017, 12 patients with pathologically confirmed primary salivary gland-type lung cancer were enrolled in First Affiliated Hospital of Nanjing Medical University. Their images and clinicopathological data were retrospectively analyzed. Results: Six out of 12 patients had mucoepidermoid carcinoma (MEC), and the other six patients had adenoid cystic carcinoma (ACC). Five MEC were located in the main bronchus, and the other one was in segmental bronchus. Intrabronchial nodule or mass with smooth or lobulated margin and calcification(n=3) was the main (18)F-FDG PET-CT features of MEC. Two ACC involved trachea, two involved the main bronchi, and the other two involved lobular bronchi. The main (18)F-FDG PET-CT features of ACC were diffuse or circumferential irregular thickness of the bronchial wall, distorted lumen, and the longitudinal extent of the tumor was greater than its transverse axis. The (18)F-FDG uptake of all lesions was increased in varying degree. The median (25th percentile, 75th percentile) value of maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were 5.1(3.1, 8.1), 5.7(1.2, 21.4)cm(3) and 18.6(0.6, 93.7), respectively. All of them were related to pathological grading and nodal tumor involvement( all P<0.05), but not associated with tumor location or pathological type( all P>0.05). MTV and TLG were also related to clinical stage( all P<0.05). Tumor size was correlated with MTV, TLG of primary lesions(r=0.607, P=0.036; r=0.579, P=0.049), but not with SUVmax(r=0.568, P=0.054). Conclusions: Primary salivary gland-type lung cancer mainly occurs in segmental bronchus. The MTV and TLG of the tumor calculated by (18)F-FDG PET-CT are correlated with clinicopathological characteristics, and are helpful for clinical diagnosis and treatment.