Current non-invasive methods for evaluating the mediastinum by computed tomographic(CT) scan have limited sensitivity and specificity. The recently introduced PET was reported to be a more sensitive and specific method for the mediastinal staging of NSCLC(sensitivity:76-100%, specificity:81-100%) than CT or MRI. We assessed the usefulness of PET in the mediastinal staging of NSCLC.

We reviewed the medical records of NSCLC patients that had undertaken staging work-up by both CT and PET before thoracotomy between January 1997 and December 1998. A total of 23 patients were enrolled in the study(14 males and 7 females) with a mean age of 61±9 years. By comparing the clinical(CT and PET) and pathologic stagings, we evaluated the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET in thoracic nodal staging.

Sensitivity, specificity, positive predicted value and negative predicted value were 38%, 40%, 25% and 50% respectively for computed tomography, and 50%, 60%, 30% and 69% for PET. The accuracy of FDG-PET in our study was lower than that reported by previous other studies.

Tne addition of FDG-PET to CT scanning has limited benefit for the thoracic nodal staging of NSCLC, but its value in our study was lower than that observed by others.