Preliminary exploration of 18F-FMISO PET/CT SUVmax with relevant factors for nasopharyngeal carcinoma

Objective To explore the relationship between the maximum standardized uptake value (SUVmax) of 18F-fluoromisonidazole (FMISO) PET/CT and the pathological classification, differentiation, T stage and primary tumor volume of nasopharyngeal carcinoma (NPC). Methods A retrospective analysis was performed on 41 patients with NPC (31 males, age 18-74 years; 10 females, age 35-67 years) who underwent head and neck 18F-FMISO PET/CT from 2012 to 2015. The relationship between the clinicopathological parameters (pathological classification, differentiation, T stage, tumor volume) of primary lesion and SUVmax were analyzed. Mann-Whitney u test, approximate t test and Spearman correlation were used for data analysis. Results There was no significant difference in SUVmax between non-keratinizing carcinoma and squamous cell carcinoma (u=183.5, P>0.05), nor between the differentiated carcinoma and undifferentiated carcinoma(t′=-1.23, P>0.05). SUVmax of T1-T2 primary tumor was significantly lower than that of T3-T4 tumor (1.52±0.43 vs 2.05±0.85; t′=-2.60, P<0.05), and SUVmax was correlated with primary tumor volume (rs=0.488, P<0.05). Conclusions The hypoxic degree is related with T stage and primary tumor volume in NPC. The combination analysis of T stage and tumor size will contribute to the assessment of oxygen level and prognosis of primary NPC. Key words: Nasopharyngeal neoplasms; Cell hypoxia; Nitroimidazoles; Fluorine radioisotopes; Positron-emission tomography; Tomography, X-ray computed