Introduction. Radiotherapy for patients with head and neck cancers raises their risk of aspiration pneumonia-related death. We aimed to develop and validate a model to predict radiation-associated aspiration pneumonia (RAP) among patients with dysphagia after radiotherapy for nasopharyngeal carcinoma (NPC). Materials and Methods. A total of 453 dysphagic patients with NPC were retrospectively recruited from Sun Yat-Sen Memorial Hospital from January 2012 to January 2018. Patients were randomly divided into training cohort () and internal validation cohort () at a ratio of 2 : 1. The concordance index (C-index) and calibration curve were used to evaluate the accuracy and discriminative ability of this model. Moreover, decision curve analysis was performed to evaluate the net clinical benefit. The results were externally validated in 203 dysphagic patients from the First People’s Hospital of Foshan. Results. Derived from multivariable analysis of the training cohort, four independent factors were introduced to predict RAP, including Kubota water drinking test grades, the maximum radiation dose of lymph node gross tumor volume (Dmax of the GTVnd), neutrophil count, and erythrocyte sedimentation rate (ESR). The nomogram showed favorable calibration and discrimination regarding the training cohort, with a C-index of 0.749 (95% confidence interval (CI), 0.681 to 0.817), which was confirmed by the internal validation cohort (C-index 0.743; 95% CI, 0.669 to 0.818) and the external validation cohort (C-index 0.722; 95% CI, 0.606 to 0.838). Conclusions. Our study established and validated a simple nomogram for RAP among patients with dysphagia after radiotherapy for NPC.

中文翻译：

---

鼻咽癌后放射性吞咽困难患者放射性吸入性肺炎预测模型的建立和验证

简介。头颈癌患者的放射治疗会增加吸入性肺炎相关死亡的风险。我们旨在开发和验证一个模型，以预测鼻咽癌 (NPC) 放疗后吞咽困难患者的放射相关吸入性肺炎 (RAP)。材料和方法。回顾性招募2012年1月至2018年1月中山纪念医院吞咽困难伴鼻咽癌患者453例，随机分为训练队列（)和内部验证队列 ()的比例为 2 : 1。使用一致性指数 (C-index) 和校准曲线来评估该模型的准确性和判别能力。此外，进行决策曲线分析以评估净临床益处。结果在佛山市第一人民医院203例吞咽困难患者中进行了外部验证。结果. 来自训练队列的多变量分析，引入了四个独立因素来预测 RAP，包括久保田饮水试验等级、淋巴结大体肿瘤体积的最大辐射剂量（GTVnd 的 Dmax）、中性粒细胞计数和红细胞沉降率。 ESR）。列线图显示了关于训练队列的良好校准和区分，C 指数为 0.749（95% 置信区间 (CI)，0.681 至 0.817），内部验证队列证实了这一点（C 指数 0.743；95% CI , 0.669 至 0.818）和外部验证队列（C 指数 0.722；95% CI，0.606 至 0.838）。结论。我们的研究在 NPC 放疗后吞咽困难患者中建立并验证了 RAP 的简单列线图。