Comparison of EUS-guided fine needle aspiration and integrated PET-CT in restaging after treatment for locally advanced non-small cell lung cancer.

BACKGROUND

After induction treatment restaging of mediastinal disease in patients with stage III non-small cell lung cancer (NSCLC) may lead to selection of candidates for further surgical treatment. Nodal down-staging is the best predictive characteristic for proceeding with surgery. We report our experience in restaging with endoscopic ultrasound-guided fine needle aspirations (EUS-FNA) and with repeated integrated positron emission tomography and computed tomography (PET-CT).

METHODS

Twenty-eight patients with stage III NSCLC were staged with integrated PET-CT, cerebral magnetic resonance imaging (MRI) and pathologically proven nodal disease. Restaging was performed with PET-CT and EUS-FNA on the same nodes that showed initially metastatic disease provided these nodal sites determined the tumor stage. Cerebral MRI was not repeated. When restaging EUS-FNA revealed no malignant cells anymore, patients were operated. The postoperative pathologic results were compared with the preoperative restaging EUS-FNA results. Also, patterns of decreased fluoro-2-deoxyglucose (FDG) uptake were compared with the postoperative pathologic results.

RESULTS

Restaging EUS-FNA was well tolerated in all patients even in those with clinical signs of radiation esophagitis. Of the 28 patients 15 were down-staged based on cytologic findings with restaging EUS-FNA and in one patient the cytology was not conclusive. Of these 15 patients, down-staging was histologically confirmed after mediastinal exploration in 11 patients and 1 patient had persistent nodal disease at resection. In 3 patients no mediastinal tissue verification was performed. Two subjects were not fit for operation, and in the other patient intraoperative nodal staging was omitted. The negative predictive value for restaging EUS-FNA was 91.6%. The accuracy of EUS-FNA was 92.3%. Concordance between findings of restaging EUS-FNA and metabolic response of lymph node metastases occurred in 17 out of 27 patients.

CONCLUSION

Restaging with EUS-FNA after induction chemo(-radiotherapy) is well tolerated and predicts the absence of nodal metastasis reliably. Although changes in mediastinal FDG-PET uptake show a high concordance with EUS-FNA, pathological confirmation is still superior and therefore necessary. EUS-FNA is the procedure of first choice for mediastinal restaging.