Use of a dual-head coincidence camera and 18F-FDG for detection and nodal staging of non-small cell lung cancer: accuracy as determined by 2 independent observers.

UNLABELLED: The accurate detection of lung carcinoma and the determination of its stage remain significant clinical problems. (18)F-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. (18)F-FDG scanning was performed using a dual-head coincidence camera 1 h after the intravenous injection of 185 MBq of (18)F-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 kappa value of 0.94 (P < 0.0001) was found for detection of the primary tumor and a kappa 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.