The prognostic value of the ratio of standard uptake value of lymph node to primary tumor before treatment of locally advanced nasopharyngeal carcinoma

Background: To evaluate the prognostic value of the ratio of the standard uptake value of the lymph node to the primary tumor before treatment of locally advanced nasopharyngeal carcinoma. Methods: : A total of 180 patients with locally advanced nasopharyngeal carcinoma diagnosed pathologically from January 1, 2016, to December 31, 2018, were selected, and the MEDEX system was used to automatically delineate lymph node metastases SUVmax (LN-SUVmax) and nasopharyngeal carcinoma primary tumor SUVmax (T-SUVmax). In addition, the ratio NTR of LN-SUVmax to T-SUVmx was calculated, and an ROC curve was drawn to obtain the best cut-off value. Kaplan–Meier and Cox regression models were used for survival and multivariate analyses, respectively. Results: : The median follow-up period of 180 patients was 32 (4–62) months. Univariate analysis showed that age ( P = 0.013), LN-SUVmax ( P = 0.001), and NTR ( P = 0.001) were factors influencing overall survival (OS). Factors affecting local progression-free survival (LPFS) were LN-SUVmax ( P = 0.005) and NTR ( P = 0.020), while clinical stage ( P = 0.023), LN-SUVmax ( P = 0.007), and NTR ( P = 0.032) were factors affecting Distant metastasis-free survival (DMFS). Multivariate analysis showed that NTR was an independent influencing factor of OS (HR = 3.00, 95%CI = 1.06–8.4, P = 0.038), LPFS (HR = 3.08, 95%CI = 1.27–7.50, P = 0.013), and DMFS (HR = 1.84, 95%CI = 0.99–3.42, P = 0.054). Taking OS as the main observation point, the best cut-off point of NTR was 0.95. Kaplan–Meier results showed that the 3-year OS (97.0% vs. 85.4%, c 2 =11.25, P = 0.001), 3-year LPFS (91.3% vs. 82.1%, c 2 = 4.035, P = 0.045), and 3-year DMFS (92.3% vs. 87.9%, c 2 = 4.576, P = 0.032) of patients with NTR 0.95. Conclusions: : High NTR before treatment may lead to poor prognosis of patients with nasopharyngeal carcinoma. This can serve as a reference value for the reasonable treatment and prognosis monitoring of such patients.