451P - Value of F-18 FDG PET/CT to identify metastatic mediastinal lymph node in NSCLC patients with bilateral benign mediastinal lymph node hyperplasia (...

Date 18 November 2017
Event ESMO Asia 2017 Congress
Session Poster lunch
Topics Non-Small-Cell Lung Cancer, Metastatic
Imaging, Diagnosis and Staging
Lung and other Thoracic Tumours
Presenter LAE HYUNG KANG
Citation Annals of Oncology (2017) 28 (suppl_10): x124-x143. 10.1093/annonc/mdx671
Authors L.H. KANG, Y.S. Kim
  • Pulmonology, Pusan National University Yangsan Hospital, 50612 - Yangsan/KR

Abstract

Background

F-18 FDG PET/CT is useful to identifying metastatic mediastinal lymph node (MLN) involvement in NSCLC patients. However, the accuracy of F-18 FDG PET in nodal staging is substantially reduced by false increases in F-18 FDG uptake in the inflammatory nodes. The efficacy of this technique is controversial because of reactively increased F-18 FDG uptake in the mediastinum, especially in regions endemic for the granulomatous disease. Here, we determined the qualitative and quantitative parameters of F-18 FDG-PET/CT for evaluation of mediastinal nodes to distinguish between malignant and benign lesions.

Methods

27 patients with pathologically documented NSCLC who showed bilateral F-18 FDG-avid MLNs on pre-treatment staging PET/CT image were included. 104 MLNs were pathologically analysed through EBUS-TBNA or MLN dissection. The MLN with prominent F-18 FDG uptake compared with other F-18 FDG-avid LNs via visual assessment was qualitatively considered as metastasis. The maximum standardized uptake value (SUVmax) of LN and SUVmax of LN to the liver and blood pool were calculated for quantifying F-18 FDG uptake. SUVmax/contra was obtained to identify metastatic MLNs.

Results

The qualitative evaluation showed sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for separating metastatic LN from benign reactive hyperplasia of 66.7%, 87.0%, 74.3%, and 88.2%, respectively. SUVmax of LN and normalized SUVmax of LN to the liver and blood pool did not significantly differ; however, SUVmax/contra was significantly higher for metastatic LNs than benign lesions. Receiver-operating-characteristic derived SUVmax/contra cut-off was 1.18 (AUC, 0.734). The quantitative evaluation showed sensitivity, specificity, PPV, and NPV of 66.7%, 75.3%, 77.4%, and 86.4%, respectively.

Conclusions

Qualitative interpretation of F-18 FDG PET/CT was superior to quantitative parameters in discriminating metastatic LNs from benign reactive hyperplasia in patients with bilateral F-18 FDG-avid mediastinal LNs. We suggest SUVmax/contra may aid in the interpretation of mediastinal nodal staging in patients with NSCLC.

Clinical trial identification

Legal entity responsible for the study

Yun Seong Kim

Funding

None

Disclosure

All authors have declared no conflicts of interest.