Long-Term Follow-Up Results From PET/CT Surveillance After Surgical Resection of Lung Adenocarcinoma Manifesting As Ground-Glass Opacity

The purpose of our study was to retrospectively evaluate the value of F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for postoperative surveillance of lung adenocarcinoma manifesting as ground-glass opacity (GGO).From May 2003 to December 2007, 111 patients with surgically resected lung adenocarcinoma manifesting as GGO were included. Clinical findings of recurrence and survival, CT features, and maximum standardized uptake value (SUVmax) were reviewed and compared among 3 groups according to GGO proportion: Group I, GGO 100%; Group II, GGO ≥50%; Group III, GGO < 50%. Disease-free survival (DFS) was estimated using the Kaplan-Meier method. Diagnostic performances of CT and PET/CT for recurrence were compared during a long-term follow-up period of >5 years.Recurrence was identified in Group III (18 of 53, 34%) but not in Groups I (n = 25) or II (n = 33) over a mean follow-up period of 74 months. Group showed significant differences in GGO proportion, SUVmax, and DFS duration (P < 0.001). PET/CT led to 6 false-positive and 5 false-negative interpretations of recurrence. For surveillance CT, sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 94.4%, 98.6%, 98.2%, 94.4%, and 98.9%, respectively; for PET/CT, sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 72.2%, 92.3%, 88.5%, 68.4%, and 93.5%, respectively. CT showed significantly higher accuracy than PET/CT (P = 0.0188).FDG-PET/CT showed no clear advantage for postoperative surveillance of lung cancer with predominant GGO because of low incidence of recurrence and frequent false-positive and false-negative results.