Assessment of Recurrence of Non-Small Cell Lung Cancer after Therapy Using CT and Integrated PET/CT

Introduction: Non-small cell lung cancer (NSCLC) has become the leading cause of cancer-related deaths in Poland. Follow-up of patients with NSCLC is aimed at early detection of local recurrence, metastatic process, treatment-related complications or second primary lung cancer. We investigated the diagnostic accuracy of FDG-PET-CT in the detection of recurrence of NSCLC after treatment. Material and methods: Seventy-two NSCLC patients (19 females, 56 males), stage I to IV, who had undergone surgery and/ /or radiation therapy, occasionally associated with chemotherapy, were retrospectively included in our study. Chest radiographs and thoracic computed tomography (CT) were performed to localize the abnormality prior to PET-CT. All the patients underwent CT and PET-CT in the period from January 2008 until January 2012. All PET images were interpreted in conjunction with thoracic CT. PET-CT and CT diagnoses were correlated with pathological diagnoses. Results: Forty-five patients had recurrent tumour. Tumour recurrence was observed more often in men than in women and also in case of neoplastic cell emboli in lymphatic or blood vessels. In three patients second primary lung cancer was diagnosed. False positive diagnosis of relapse based on PET-CT was obtained in 4 patients, mainly due to inflammatory lesions. The accuracy of PET-CT for diagnosis of recurrence was 94.4% (95% CI 91; 100). Conclusions: FDG PET-CT was the best method to differentiate recurrent bronchogenic carcinoma from inflammatory lesions, especially at post-therapeutic sites. It has been shown that PET-CT is more accurate method than CT in recurrent NSCLC. PET-CT results had a further impact on the clinical management and treatment planning.