Non-Small Cell Lung Cancer: Accuracy as Determined by 2 Independent Observers

The accurate detection of lung carcinoma and the determination of its stage remain significant clinical problems. 18F-FDG PET has been shown to improve detection and staging of lung cancer and to prevent unnecessary invasive procedures. Positron imaging with dual-head gamma cameras may not be as sensitive as PET, but recent studies have shown good results with these cameras. Methods: In the present study, we investigated 100 patients, 76 of whom were male and 24 female (mean age SD, 60.7 9.4 y), with suspected non‐small cell lung cancer. 18F-FDG scanning was performed using a dualhead coincidence camera 1 h after the intravenous injection of 185 MBq of 18F-FDG. For 46 patients, attenuation correction was also performed. Two independent observers unaware of clinical status analyzed all imaging studies. TNM classification was assigned after surgical staging. Results: In 44 patients with clinically suspected bronchogenic carcinoma, no evidence of malignancy was found. However, in 56 patients a pulmonary neoplasm was demonstrated. At interobserver analysis, a value of 0.94 (P 0.0001) was found for detection of the primary tumor and a value of 0.63 (P 0.0001) was found for mediastinal staging. A sensitivity of 96%, a specificity of 93%, and an accuracy of 95% were found for detection of pulmonary neoplasm. Assessment of lymph node involvement showed a sensitivity of 50%, a specificity of 92%, and an accuracy of 77%. The sensitivity of CT in assessing lymph node involvement was 36%, the specificity was 86%, and the accuracy was 67%. Attenuation correction provided more anatomic information, but no differences were seen between attenuation-corrected and non‐attenuation-corrected images for detecting lesions or lymph node involvement. Conclusion: The present study confirms earlier data showing that 18 F-FDG scans obtained with dual-head coincidence cameras are useful in the detection of non‐small cell lung cancer and less suitable for staging of lymph node involvement, with accuracy comparable to that of CT.