New <scp>PET</scp>/<scp>CT</scp> criterion for predicting lymph node metastasis in resectable advanced (stage <scp>IB‐III</scp>) lung cancer: The standard uptake values ratio of ipsilateral/contralateral hilar nodes
Komei Kameyama, Kazuhiro Imai, Koichi Ishiyama, Shinogu Takashima, Shoji Kuriyama, Maiko Atari, Yoshiaki Ishii, Akihito Kobayashi, Shugo Takahashi, M. Kobayashi, Yuzu Harata, Yusuke Sato, Satoru Motoyama, Manabu Hashimoto, Kyoko Nomura, Yoshihiro Minamiya
Abstract
Abstract Background The aim of the present study was to use surgical and histological results to develop a simple noninvasive technique to improve nodal staging using preoperative PET/CT in patients with resectable lung cancer. Methods Preoperative PET/CT findings (pStage IB–III 182 patients) and pathological diagnoses after surgical resection were evaluated. Using PET/CT images to determine the standardized uptake value (SUV) ratio, the SUV max of a contralateral hilar lymph node (on the side of the chest opposite to the primary tumor) was measured simultaneously. The I/C‐SUV ratio was calculated as ipsilateral hilar node SUV/contralateral hilar node SUV. Receiver operating characteristic (ROC) curves were then used to analyze those data. Results Based on ROC analyses, the cutoff I/C‐SUV ratio for diagnosis of lymph node metastasis was 1.34. With a tumor ipsilateral lymph node SUV max ≥2.5, an IC‐SUV ratio ≥1.34 had the highest accuracy for predicting N1/N2 metastasis; the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of nodal staging were 60.66, 85.11, 84.09, 62.5 and 71.29%, respectively. Conclusions When diagnosing nodal stage, a lymph node I/C‐SUV ratio ≥1.34 can be an effective criterion for determining surgical indications in advanced lung cancer.