Diagnostic utility of metabolic parameters on FDG PET/CT for lymph node metastasis in patients with cN2 non-small cell lung cancer

Abstract

Background The aim of this study was to assess the diagnostic utility of metabolic parameters on fluorine-18-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET)/computed tomography (CT) for predicting lymph node (LN) metastasis in patients with cN2 non-small cell lung cancer (NSCLC). Methods We retrospectively reviewed patients who underwent surgery for cN2 NSCLC between 2007 and 2020. Those who had clinically diagnosed positive hilar and mediastinal LNs by routine CT and PET/CT imaging were investigated. To measure the metabolic parameters of LNs, the data according to maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and LN-to-primary tumor ratio of SUVmax (LPR) were examined. The diagnosis of each retrieved LN was confirmed based on histopathological examination of surgical tissue specimens. Receiver operating characteristics (ROC) curves with area under the curve (AUC) calculations and multivariate analysis by logistic regression were performed. Results Forty-five patients with 84 clinically diagnosed positive hilar or mediastinal LNs were enrolled in the present study. Of the 84 LNs, 63 LNs were pathologically proven as positive (75%). The SUVmax, MTV, TLG, and LPR of LN metastasis were significantly higher than those of benign nodes. In the ROC analysis, the AUC value of LPR [AUC, 0.776; 95% confidence interval (CI), 0.640–0.913] was higher than that of LN SUVmax (AUC, 0.753; 95% CI, 0.626–0.880) or LN TLG3.5 (AUC, 0.746; 95% CI, 0.607–0.885). Using the optimal LPR cutoff value of 0.47, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 84.1, 66.7, 88.3, 58.3, and 79.8%, respectively. Multivariate analysis by logistic regression showed that LPR was an independent predictor for LN metastasis (odds ratio, 6.45; 95% CI, 1.785–23.301; P = 0.004). In the subgroup analysis of adenocarcinoma patients (n = 18; 32 LNs), TLG3.5 was a better predictor (AUC, 0.816; 95% CI, 0.639–0.985) than LPR (AUC, 0.792; 95% CI, 0.599–0.986) or LN SUVmax (AUC, 0.792; 95% CI, 0.625–0.959). Conclusions Our findings suggest that LPR on FDG-PET is a useful predictor for LN metastasis in patients with cN2 NSCLC. TLG can be a good predictor for LN metastasis in patients with adenocarcinoma.

18F-FAPI PET/CT performs better in evaluating mediastinal and hilar lymph nodes in patients with lung cancer: comparison with 18F-FDG PET/CT

“…In addition, our study showed that 18 F-FAPI PET/CT was more sensitive and specific than 18 F-FDG in diagnosing mediastinal and hilar lymph nodes, consistent with previous studies [ 21 ]. The variable positive predictive rate for the assessment of mediastinal lymph node involvement with 18 F-FDG PET/CT has also been recognized, ranging from 32.3% to 89% [ 22 , 23 ]. The low and dispersive predictive rate limits the application of 18 F-FDG in the assessment of mediastinal lymph nodes, and our results suggest that 18 F-FAPI PET/CT might be an alternative imaging technique.…”

Usefulness of pyruvate dehydrogenase-E1α expression to determine SUVmax cut-off value of [18F]FDG-PET for predicting lymph node metastasis in lung cancer

“…A systematic review reported that [ 18 F]FDG-PET/CT has a sensitivity of 0.774 and specificity of 0.901 in diagnosing preoperative lymph node metastasis 23 . Although there were many studies aimed to improve the accuracy of [ 18 F]FDG-PET/CT in diagnosing lymph node metastasis, most studies reported less accuracy in clinical practice 5 , 21 , 24 – 26 . On the other hand, our new SUVmax cut-off value according to PDH-E1α expression showed higher specificity for [ 18 F]FDG-PET in the diagnosis of lymph node metastasis.…”

“…On the other hand, our new SUVmax cut-off value according to PDH-E1α expression showed higher specificity for [ 18 F]FDG-PET in the diagnosis of lymph node metastasis. To improve the accuracy of the test, new original standards have been reported, such as changing the cut-off value or adding further parameters in addition to SUVmax 5 , 21 , 24 – 26 , but they are based on clinical parameters only. The novel aspect of our study is to define a new SUVmax cut-off value for [ 18 F]FDG-PET/CT based on the molecular biological aspects of glucose metabolic enzymes.…”

Preoperative nomogram for predicting spread through air spaces in clinical-stage IA non-small cell lung cancer using 18F-fluorodeoxyglucose positron emission tomography/computed tomography

“…18 F-FDG PET/CT, as a noninvasive imaging method, can simultaneously depict the morphological characteristics and glucose metabolic activity of tumors, exhibiting high accuracy in predicting tumor invasion, lymph node metastasis, and visceral pleural invasion (Volpi et al 2018 ; Li et al 2022a , b ; Nakanishii et al 2021 ; Wang et al 2023 ). Previous studies have indicated correlations between certain CT features of lung cancer and STAS status, offering a potential means of predicting STAS before surgery (Yin et al 2020 ).…”