Department of Radiation Oncology, Guangxi Medical University Cancer Hospital, Nanning, Guangxi 530021, P.R. China.
Aging (Albany NY). 2020 Jan 31;12(2):1857-1866. doi: 10.18632/aging.102717.
Xerostomia is a common radiation-induced late complication after radiotherapy. Identifying predictive factors for xerostomia will lead to better treatments and improve the quality of life. This study was conducted to establish an effective predictive nomogram for xerostomia by assessing stage I-IVb (AJCC 7th edition) NPC patients between September 2015 and March 2016. Xerostomia was evaluated via the RTOG/EORTC system. The primary endpoint was grade 2-3 xerostomia 1 year after treatment. The predictive factors for xerostomia were analysed using logistic regression analysis. A nomogram was constructed based on combining the predictors and clinical variables. In total, 102 patients with grade 0-1 xerostomia and 93 patients with grade 2-3 xerostomia were included. The independent predictive factors for xerostomia were V25, V30, V35, and V45 of the ipsilateral parotid gland and mean dose of the contralateral parotid gland. The calibration plot for the probability of xerostomia showed good agreement between prediction by the nomogram and actual observation. The concordance index of the nomogram for predicting xerostomia was 0.796 (95% CI: 0.735-0.857, P <0.001), which was higher than any single dosimetric parameter. Our results indicated that the nomogram provided a more accurate prediction of grade 2-3 xerostomia 1 year after treatment.
口干症是放疗后常见的晚期放射性损伤。确定口干症的预测因素将有助于制定更好的治疗方案，提高生活质量。本研究旨在通过评估 2015 年 9 月至 2016 年 3 月间 I-IVb 期（AJCC 第 7 版）NPC 患者，建立一种有效的口干症预测列线图。采用 RTOG/EORTC 系统评估口干症。主要终点为治疗后 1 年发生 2-3 级口干症。采用 logistic 回归分析口干症的预测因素。基于预测因子和临床变量构建列线图。共纳入 102 例口干症 0-1 级和 93 例口干症 2-3 级患者。同侧腮腺 V25、V30、V35 和 V45 以及对侧腮腺平均剂量是口干症的独立预测因子。口干症概率的校准图显示，列线图预测与实际观察之间具有良好的一致性。列线图预测口干症的一致性指数为 0.796（95%CI：0.735-0.857，P<0.001），高于任何单一剂量学参数。研究结果表明，该列线图能更准确地预测治疗后 1 年 2-3 级口干症的发生。
