Abstract
BACKGROUND AND OBJECTIVE: The application and the value of PET/CT in lung cancer are on the way to development. The aim of this study is to summarize the data from 419 patients with pulmonary tumor or tumor-like disease and to explore the appliance of PET/CT. METHODS: From Dec 2007 to Aug 2011, 594 patients with pulmonary tumor or tumor-like disease underwent PET/CT examination during the different course of treatment, which were treated by single surgery team from Peking University Cancer Hospital. Of these patients, 419 cases diagnosed pathologically were included into study. The clinicapathological and follow-up data were collected to analyze the value of PET/CT in diagnosis, TNM staging, therapy response evaluation and posttherapy monitoring. RESULTS: Four hundred and nineteen cases comprised of 63 benign and 356 malignant, of which, 338 were primary lung cancer, and 18 were metastases. The SUVmax cutoff was defined as 2.5 to differentiate the benign and malignant disease. PET/CT obtained the role of diagnosis with sensitivity as 85.0%, specificity as 52.4%, accuracy rate as 79.2%, positive predictive value as 89.2% and negative predictive value as 42.9%, respectively. Of 338 primary cases, 275 underwent PET/CT at initial diagnosis, in which, 46 (16.7%) distant metastasis were found, including 8 additional metastasis not found by conventional utilities. Six of 43 recurrences were found by PET/CT following conventional examination. In T staging, SUVmax is positively correlated with diameter of tumors (P<0.05). In N staging, 610 stations of lymph nodes were resected from 168 cases, with 37 stations predicted as positive by PET/CT and 102 stations pathologically proven positive, therefore, calculating the sensitivity as 36.3%, specificity as 93.9%, accuracy rate as 84.3%, positive predictive value as 54.4% and negative predictive value as 88.0%, respectively. Ten patients underwent PET/CT scan for chemotherapy response evaluation, with SUVmax changing following T downstaging. CONCLUSION: PET/CT is one optional method for diagnosis of pulmonary tumors. In TNM staging, PET/CT showed the superiority than conventional utilities in M staging, but possesses the high specificity but inferior sensitivity in N staging. Therefore, PET/CT should be used as routine examination for postoperation follow-up. Furthermore, PET/CT performed the outstanding role in chemotherapy response evaluation.