RESUMEN
OBJECTIVE: To evaluate the application value of (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) in early diagnosis of lung cancer. METHODS: Retrospective analyses were conducted for 347 cases of pulmonary space-occupying lesions at Zhongshan Hospital from June 2010 to October 2012. The diagnostic validity of PET/CT and fluorodeoxyglucose maximum standardized uptake value (SUVmax) of lesions were compared respectively. Among different morphological characteristics, pathologic types and levels of tumor markers. The diagnostic value of PET/CT was also evaluated along with serum tumor markers for lung cancer. RESULTS: SUVmax was positively correlated with lesion size (r = 0.484, P < 0.05) and negatively with tumor differentiation degree (r = -0.232, P < 0.01). It was significantly higher in tumor marker positive group than the negative group (10.6 ± 5.5 vs 7.6 ± 5.4, P < 0.05). The diagnostic specificity, sensitivity and accuracy of PET/CT were 50.0%, 96.6% and 89.3% in lung cancer. And the greater the lesion, the higher the diagnostic accuracy (P < 0.05). PET/CT plus serum tumor markers could boost the diagnostic specificity of lung cancer by 30% (P < 0.01). CONCLUSIONS: (18)F-FDG PET/CT has high diagnostic values for early stage pulmonary nodules. It can also suggest the differentiation degree of lung cancer. Combined use of serum tumor markers and (18)F-FDG PET/CT increases the early diagnostic specificity of lung cancer.