PET/CT using 18F-FDG in suspected lung cancer recurrence: diagnostic value and impact on patient management.

The goal of this study was to assess the value of hybrid imaging using a combined PET/CT device with 18F-FDG in the diagnosis and clinical management of suspected recurrent lung cancer. METHODS: Forty-two patients with non-small cell lung cancer (NSCLC) with suspected recurrence due to new clinical, biochemical, and radiologic findings were prospectively evaluated. PET/CT results were compared with PET interpreted with side-by-side CT data. A final diagnosis of recurrence was confirmed by histologic tissue sampling during surgery or biopsy or by further clinical and radiologic work-up. The impact of PET/CT on patient management was assessed. RESULTS: Twenty-four of 27 positive PET/CT studies (89%) were proven to have recurrent disease. Fourteen of 15 negative PET/CT studies (93%) had no evidence of disease. The sensitivity, specificity, and positive and negative predictive values of PET/CT for diagnosis of recurrence were 96%, 82%, 89%, and 93% compared with 96%, 53%, 75%, and 90%, respectively, for PET. PET/CT changed the PET lesion classification in 22 patients (52%), by determining the precise localization of sites of increased 18F-FDG uptake. PET/CT changed the management of 12 patients (29%) by eliminating previously planned diagnostic procedures (5 patients), by initiating a previously unplanned treatment option (4 patients), or by inducing a change in the planned therapeutic approach (3 patients). CONCLUSION: In patients with a suspected recurrence of NSCLC, PET/CT provides a better anatomic localization of suspicious lesions compared with PET interpreted with side-by-side CT data. This improved diagnostic performance of PET/CT has a further impact on the clinical management and treatment planning of the patients.