New PET/CT criterion for nodal staging in non-small cell lung cancer: measurement of the ratio of section area of standard uptake values ≥2.5/lymph node section area.

Abstract

The aim of the present study was to use surgical and histological results to develop a simple noninvasive technique for improving nodal staging using preoperative PET/CT in patients with resectable non-small cell lung cancer (NSCLC). Preoperative PET/CT findings (163 patients) and pathological diagnoses after surgical resection were evaluated. Using PET/CT images, lymph node section area (SA), the maximum standardized uptake value (SUVmax), SA of SUV ≥2.5 and ≥3.0 were drawn freehand and measured using caliper software. Receiver operating characteristic (ROC) curves were then used to analyze those data. Based on ROC analyses, the cut-off values for SA of SUV ≥2.5, SA of SUV ≥3.0, SUV ≥2.5 SA/node SA and SUV ≥3.0 SA/node SA for diagnosis of lymph node metastasis were 200mm2, 30mm2, 1.0 and 0.4. SUV ≥2.5 SA/node SA ≥1.0 had the highest negative predictive value, and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of nodal staging were 61.1, 73.4, 36.7, 88.2 and 70.9%. When diagnosing nodal staging based a lymph node SUV ≥2.5 SA/node SA ratio of ≥1.0, it can be an effective criterion for use to determine surgical indications.