**Prognostic Value of Combing Primary Tumor and Nodal Glycolytic–Volumetric Parameters of 18F-FDG PET in Patients with Non-Small Cell Lung Cancer and Regional Lymph Node Metastasis**

**Yu-Hung Chen 1,2, Sung-Chao Chu 2,3, Ling-Yi Wang 4, Tso-Fu Wang 2,3, Kun-Han Lue 5, Chih-Bin Lin 2,6, Bee-Song Chang 7, Dai-Wei Liu 2,8, Shu-Hsin Liu 1,5 and Sheng-Chieh Chan 1,2,\***



**Abstract:** We investigated whether the combination of primary tumor and nodal 18F-FDG PET parameters predict survival outcomes in patients with nodal metastatic non-small cell lung cancer (NSCLC) without distant metastasis. We retrospectively extracted pre-treatment 18F-FDG PET parameters from 89 nodal-positive NSCLC patients (stage IIB–IIIC). The Cox proportional hazard model was used to identify independent prognosticators of overall survival (OS) and progression-free survival (PFS). We devised survival stratification models based on the independent prognosticators and compared the model to the American Joint Committee on Cancer (AJCC) staging system using Harrell's concordance index (c-index). Our results demonstrated that total TLG (the combination of primary tumor and nodal total lesion glycolysis) and age were independent risk factors for unfavorable OS (*p* < 0.001 and *p* = 0.001) and PFS (both *p* < 0.001), while the Eastern Cooperative Oncology Group scale independently predicted poor OS (*p* = 0.022). Our models based on the independent prognosticators outperformed the AJCC staging system (c-index = 0.732 versus 0.544 for OS and c-index = 0.672 versus 0.521 for PFS, both *p* < 0.001). Our results indicate that incorporating total TLG with clinical factors may refine risk stratification in nodal metastatic NSCLC patients and may facilitate tailored therapeutic strategies in this patient group.

**Keywords:** 18F-FDG; PET; non-small cell lung cancer; prognosis; glycolytic; volumetric

**Citation:** Chen, Y.-H.; Chu, S.-C.; Wang, L.-Y.; Wang, T.-F.; Lue, K.-H.; Lin, C.-B.; Chang, B.-S.; Liu, D.-W.; Liu, S.-H.; Chan, S.-C. Prognostic Value of Combing Primary Tumor and Nodal Glycolytic–Volumetric Parameters of 18F-FDG PET in Patients with Non-Small Cell Lung Cancer and Regional Lymph Node Metastasis. *Diagnostics* **2021**, *11*, 1065. https://doi.org/10.3390/ diagnostics11061065

Academic Editors: F.H.P. van Velden and Lioe-Fee de Geus-Oei

Received: 25 May 2021 Accepted: 8 June 2021 Published: 9 June 2021

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