Role of positron emission tomography in mediastinal lymphatic staging of non-small cell lung cancer.
OBJECTIVE
Positron emission tomography (PET) is used increasingly in staging of non-small cell lung cancer (NSCLC) as a non-invasive tool. The role of the PET in mediastinal lymphatic staging of NSCLC is not clear. We aimed to demonstrate the efficacy of PET in determining mediastinal lymphatic metastasis by comparing the results of PET with mediastinoscopy.


METHODS
We performed PET preoperatively in 170 patients with clinically operable NSCLC between 2004 and 2006. Stations defined as metastasis by PET (SUV(max) >2.5) were recorded. Mediastinoscopy was performed initially in all patients and a total of 687 stations which can be reached with mediastinoscope were sampled (mean 4.04). Forty-three patients with mediastinal metastasis were referred to the oncology clinic for chemotherapy while lung resection and complete mediastinal lymphatic dissection through thoracotomy was performed in the remaining 127 patients. Involvement of mediastinal lymph nodes was verified to compare the sensitivity and specificity of mediastinoscopy and the related PET results.


RESULTS
Histopathologic classification of the tumors revealed 79 squamous carcinomas and 58 adenocarcinomas. False positivity rate of PET was 26% (95% CI: 14-38), false negativity was 25% (95% CI: 18-33), sensitivity was 74% (95% CI: 63-86), specificity was 73% (95% CI: 66-82) and accuracy was 74% in mediastinal staging. Negative predictive value of mediastinoscopy was 94% (95% CI: 89-98), positive predictive value 100%, sensitivity 84% (95% CI: 74-94), specificity 100% and accuracy was 95%.


CONCLUSIONS
PET results do not provide acceptable accuracy rates. Mediastinoscopy still remains the gold standard for mediastinal staging of NSCLC, although it cannot reach to all the mediastinal stations.
Melek
Huseyin
H
Yedikule Chest Diseases and Thoracic Surgery Education and Research Hospital, Department of Thoracic Surgery, Istanbul, Turkey. hmelek77@hotmail.com
Gunluoglu
Mehmet Zeki
MZ
Demir
Adalet
A
Akin
Hasan
H
Olcmen
Aysun
A
Dincer
Seyyit Ibrahim
SI
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000556:secondary; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008481:Mediastinoscopy; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D018579:Patient Selection; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D012680:Sensitivity and Specificity