Staging of lymph nodes with FDG dual-headed PET in patients with non-small-cell lung cancer

Accurate assessment of mediastinal lymph node involvement in patients with non-small-cell lung cancer (NSCLC) is necessary to select patients for dire ct surgical treatment. The aims of the present study were to assess the fea sibility of staging NSCLC with FDG using a dual-headed positron emission to mographic (PET) camera and to compare this non-invasive technique with comp uted tomography (CT) and lymph node sampling, since both modalities are cur rently used for staging NSCLC. Thirty-three patients (29 men and 4 women, m ean age 60 years) with newly diagnosed NSCLC were studied. In all patients, CT, FDG dual-headed PET and mediastinoscopy were performed within 4 weeks. The results of mediastinoscopy were used to select patients for thoracotom y. For both the assessment of individual lymph node involvement and the pat ient-based classification, the results of FDG dual-headed PET and CT were c ompared using the McNemar test. Thirty-one of 187 lymph nodes studied conta ined tumour metastases. FDG dual-headed PET showed a significantly higher s ensitivity (P < 0.001) and specificity (P < 0.001) than CT. FDG dual-headed PET and CT correctly staged 27 and 20 patients, respectively. Due to the s ignificantly higher negative predictive value of FDG dual-headed PET versus CT (P = 0.012), it was a better non-invasive diagnostic tool for selecting patients for surgery. In seven of eight patients, additional intrapulmonar y sites of increased uptake were found, which revealed malignancy on histol ogical examination. CT was false-negative in three of these patients. In on e patient, increased FDG uptake was caused by an infection. In conclusion, it is possible to stage mediastinal lymph nodes in patients with NSCLC usin g a dual-headed PET camera. The high negative predictive value of FDG dual- headed PET suggests that mediastinoscopy may be omitted in patients with NS CLC. ((C) 1999 Lippincott Williams & Wilkins).