FDG-PET parameters predicting mediastinal malignancy in lung cancer

Abstract

BackgroundStaging of mediastinal lymph nodes in non-small cell lung cancer (NSCLC) is mandatory. The maximum Standard Uptake Value (SUVmax) obtained using F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is the best non-invasive technique available for this evaluation, but its performance varies from center to center. The aim of the present study was to identify FDG-PET predictors of mediastinal malignancy that are able to minimize intercenter variability and improve the selection of subsequent staging procedures.MethodA multicenter study of NSCLC patients staged through FDG-PET and endobronchial ultrasonography with needle aspiration (EBUS-NA) was performed using therapeutic surgery with systematic nodal dissection as gold standard. Intercenter variability and predictive power for mediastinal malignancy of different FDG-PET measures were assessed, as well as the role of these measures for selecting additional staging procedures.ResultsOne hundred and twenty-one NSCLC patients, of whom 94 (72%) had ≥1 hypermetabolic spots in the mediastinum, were included in the study. Mean SUVmax of the primary tumor was 12.3 (SD 6.3), and median SUVmax of the highest hypermetabolic spots in the mediastinum was 3.9 (IQR 2.4-7). Variability of FDG-PET measures between hospitals was statistically significant (p = 0.016 and p < 0.001 respectively), but lost significance when SUVmax in the mediastinum was expressed as a ratio or a subtraction from the primary tumor (SUVmax mediastinum/tumor, p = 0.083; and SUVmax mediastinum - tumor, p = 0.428 respectively). SUVmax mediastinum/tumor showed higher accuracy in the ROC analysis (AUC 0.77 CI 0.68-0.85, p < 0.001), and showed predictive power for mediastinal malignancy when using a 0.4 cutoff (OR 6.62, 95%CI 2.98-14.69). Sensitivities and negative predictive values of clinical staging through EBUS-NA attained values ranging between 57% and 92% after FDG-PET, which improved with additional techniques when the tumor had a diameter >3 cm and/or a SUVmax mediastinum/tumor ratio >0.4.ConclusionThe SUVmax mediastinum/tumor ratio is a good predictor of regional tumor extension in NSCLC. This measure is not influenced by intercenter variability and has an accuracy of over 70% for the identification of malignancy when using a 0.4 cutoff.

Methylation Assessment for the Prediction of Malignancy in Mediastinal Adenopathies Obtained by Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration in Patients with Lung Cancer

“…As reported in other studies [32,33,37] and confirmed in our work, patient’s age, lymph node size, and SUV uptake are factors associated with increased likelihood of malignancy of lymphadenopathies. The combination of these variables and sex, together with the methylation biomarkers MGMT , E-cadherin , and SHOX2 , improved the detection of lymphatic micrometastases in negative conventional evaluation.…”

18F-fluorodeoxyglucose positron-emission tomography (FDG-PET)-Radiomics of metastatic lymph nodes and primary tumor in non-small cell lung cancer (NSCLC) – A prospective externally validated study

“…Images were imported into the research treatment planning system Xio/Focal (development cohort) and Eclipse (validation cohort) using the DICOM protocol. The primary gross tumor volume (tumor) and metastatic hilar/mediastinal lymph nodes (LN), identified as PET positive and/or proven by endoscopic ultrasound bronchoscopy/esophagoscopy (EBUS/EUS), were manually delineated by experienced radiation oncologists on the fused FDG-PET-CT images, and used as the regions of interest for analysis [ 10 – 12 ]. A single structure representing all metastatic lymph nodes, regardless of their number, was derived for each patient (see online appendix for further details).…”

Usefulness of Positron Emission Tomography in the Examination of Hilar and Mediastinal Lymphadenopathies in Patients with Suspicion of Lung Cancer

“…e most widely used SUV max cutoff point is 2.5 [27], though others determine the SUV max value using the ROC curve analysis for the best S and SP relationship, generally obtaining values higher than 2.5 [28,29]; (c) whether or not to include hilar lymph nodes. Since their presence has prognostic connotations but does not modify the therapeutic attitude, some authors solely study the mediastinal lymph nodes; and (d) the pulmonary adenocarcinoma rate.…”