Diagnosis of recurrence and follow-up using FDG-PET/CT for postoperative non-small-cell lung cancer patients

Background: There is currently no consensus regarding the best program for postoperative follow-up and surveillance after a curative resection for non-small-cell lung cancer (NSCLC) patients. We examined the diagnostic capability of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for detecting recurrence in postoperative NSCLC patients, and we evaluated the results of postoperative surveillance using FDG-PET/CT in asymptomatic patients.

Patients and methods: Between 2005 and 2013, 496 FDG-PET/CT examinations were performed to detect recurrences for 187 NSCLC patients who had undergone potentially curative operations at our institution. Follow-up FDG-PET/CT was performed ≥ 1 × /year in principle in 172 asymptomatic patients without clinical or radiological evidence of recurrence, and the results were retrospectively reviewed.

Results: FDG-PET/CT correctly diagnosed recurrence in 46 of 47 (97.9%) patients and 68 of 69 (98.6%) recurrent sites. The following were obtained: 97.9% sensitivity, 97.1% specificity, 92.0% positive predictive value, 99.3% negative predictive value, and 97.3% accuracy. In six patients, other diseases were detected and treated appropriately. In asymptomatic patients, the detection rate of recurrence in the stage III group was significantly higher than the detection rates in the stage I and II groups, and FDG-PET/CT performed ≤ 3 years post-resection detected significantly more FDG-positive lesions compared to that performed after 4 years.

Conclusion: FDG-PET/CT is very useful for detecting recurrence in NSCLC patients after a potentially curative operation. It might be sufficient to perform follow-up FDG-PET/CT until 3 years post-resection for advanced-stage patients. Further randomized clinical trials are needed to determine whether the early detection of recurrences leads to better prognoses.

Keywords: Asymptomatic postoperative patients; FDG-PET/CT; Follow-up; Non-small-cell lung cancer.