Current Thoracic Surgery 2018 , Vol 3 , Issue 2
Do we need a new SUVmax threshold value for the evaluation of mediastinal lymph nodes?
Özgur Ömer Yıldız1,Serdar Özkan2,Göktan Temiz3,Ömer Cenap Gülyüz4,Nurettin Karaoğlanoğlu5
1Department of Thoracic Surgery, Yildirim Beyazit University, Yenimahalle Education and Research Hospital, Ankara, Turkey
2Department of Thoracic Surgery, Medova Hospital, Konya, Turkey
3Department of Thoracic Surgery, Adana City Education and Research Hospital, Adana, Turkey
4Department of Thoracic Surgery, Adıyaman University Education and Resarch Hospital, Adiyaman, Turkey
5Department of Thoracic Surgery, Yildirim Beyazit University, Faculty of Medicine, Ankara, Turkey
DOI : 10.26663/cts.2018.0009 Background: Mediastinal lymph node involvement is the most important factor determining the treatment and the prognosis with non-small cell lung cancer (NSCLC). In our study, the role of PET-CT was assessed in the evaluation of intrathoracic lymph node involvement in patients with preoperative NSCLC.

Materials and Methods: The study included 510 cases selected according to the criteria identified between January 2009 and July 2011. PET-CT staging and thorax-CT, size of lymph nodes, histological type of tumor, mediastinal lymph nodes taken and the pathological results were assessed.

Results: SUVmax cut-off value was taken as 2.5 for the metastatic analysis of lymph nodes in PETCT and N1 and N2 lymph node stations were evaluated. Sensitivity for the N2 lymph node stations, was 74.7%, specificity 49.4%, Positive Predictive Value 25.4%, Negative Predictive Value 89,.5% and accuracy 54.1% (p < 0.001). Following the statistical analysis, the new SUVmax cut-off value for the N1 lymph node groups was calculated as 3.34, and for N2 lymph node groups 5.6. Based on the new SUVmax cut-off value for N2 lymph node groups, the sensitivity of PET-CT was calculated as 43.2%, specificity 94.4%, PPV 64.1%, NPV 87.8% and accuracy 84.9% (p < 0.001).

Conclusions: Calculating a new cut off value of SUVmax all around the world would increase the NPV of PET-CT and so it would reduce to use of invasive methods. PPV of PET-CT is still not at an acceptable level, so positive results of PET-CT for mediastinal lymph node staging should be confirmed with invasive diagnostic techniques. Keywords : non-small cell lung cancer, lymph node, PET-CT, staging