¹⁸F-fluorodeoxyglucose positron emission tomography in small-cell lung cancer

Positron emission tomography (PET) imaging is not used routinely in small-cell lung cancer (SCLC) but has been proven useful in non-small-cell lung cancer. The performance of ¹⁸F-fluorodeoxyglucose (FDG)-PET in patients with SCLC was evaluated in this study. Fifteen patients with proven SCLC were evaluated (8 men and 7 women; mean age, 68 years; range, 50-81 years). Among the 15 patients with SCLC, 3 were newly diagnosed and 12 had received chemotherapy or radiation therapy before PET. Five patients underwent surgery (3 newly diagnosed and 2 after therapy) after PET scan, and 14 received chemotherapy, radiation therapy, or both. The patient who was not treated with chemotherapy or radiation therapy underwent surgery only. All patients had computed tomographic (CT) scans before PET and had clinical follow-up for at least 2 months after PET. The patients received 3.4 to 4.15 mCi of ¹⁸F-FDG intravenously after fasting for at least 4 hours. Whole-body PET scans were acquired approximately 50 min after injection by using an ADAC Laboratories C-PET plus scanner. Among the 12 patients treated before PET, 2 were found with solitary pulmonary nodules positive on PET. Subsequent surgical resection and pathology showed 1 true positive and 1 false positive (postradiation pneumonitis). Six of these 12 patients had extrapulmonary metastases or large intense hilar or pulmonary uptake on PET, or both. Four of these 12 had no evidence of abnormal FDG uptake and were considered true negatives. The 3 patients with newly diagnosed SCLC were all true positives on PET, confirmed by surgery. One false negative on CT scan was attributed to postradiation fibrosis. These preliminary data suggest that whole-body FDG-PET can provide the basis for determining which treatment modality would be the most appropriate during the early stages of SCLC, when surgery is still an option, and it is a useful tool to assess the effect of treatment in patients with this disease. A more accurate assessment of SCLC will be possible if FDG-PET scan is combined with CT during the early evaluation of these patients.