原发肿瘤体积对T3-4期鼻咽癌患者预后分层的补充价值：一项回顾性队列研究

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中文摘要

本回顾性研究评估了鼻咽原发肿瘤大体肿瘤体积（GTVnx）在T3-4期鼻咽癌（NPC）患者总生存（OS）风险分层中的补充价值。共纳入2020年3月至2025年6月期间在桂林市人民医院（中国桂林）接受根治性调强放疗的118例T3-4期NPC患者。GTVnx从放疗计划系统中获取。采用时间依赖性受试者工作特征（ROC）曲线确定预测3年OS的探索性截断值。采用Kaplan-Meier法和log-rank检验评估生存差异，并使用Cox比例风险模型评估GTVnx与OS之间的关联。使用一致性指数（C-index）、赤池信息准则（AIC）和时间依赖性曲线下面积（AUC）比较临床模型与扩展模型，并进行敏感性分析以评估稳健性。中位随访时间为34.1个月，发生18例死亡（15.3%）。36个月时间依赖性ROC分析确定78 cm3为GTVnx的探索性截断值，AUC为0.709。高GTVnx患者的OS低于低GTVnx患者（log-rank P<0.001）。在多变量Cox分析中，校正T分期和治疗前Epstein-Barr病毒DNA（EBV DNA）后，高GTVnx仍与较差的OS相关（风险比4.375；95%置信区间1.474-12.986；P=0.008）。将GTVnx加入临床模型后，C-index从0.759提高至0.817，AIC从135.151降低至133.085，36个月AUC从0.748提高至0.787。敏感性分析支持主要发现的一致性。GTVnx可能为T3-4期NPC患者提供超越T分期和治疗前EBV DNA的补充预后信息。然而，所确定的截断值和增量预后价值需要在独立队列中验证。

英文摘要

The present retrospective study evaluated the supplementary value of gross tumor volume of the primary nasopharyngeal tumor (GTVnx) for overall survival (OS) risk stratification in patients with T3-4 nasopharyngeal carcinoma (NPC). A total of 118 patients with T3-4 NPC who received definitive intensity-modulated radiotherapy at Guilin People's Hospital (Guilin, China) between March 2020 and June 2025 were included. GTVnx was obtained from the radiotherapy planning system. A time-dependent receiver operating characteristic (ROC) curve was used to determine the exploratory cut-off for predicting 3-year OS. Survival differences were assessed using the Kaplan-Meier method and log-rank test, and Cox proportional hazards models were used to evaluate the association between GTVnx and OS. Clinical and extended models were compared using the concordance index (C-index), Akaike information criterion (AIC) and time-dependent area under the curve (AUC), and sensitivity analyses were performed to assess robustness. The median follow-up time was 34.1 months and 18 deaths occurred (15.3%). The 36-month time-dependent ROC analysis identified 78 cm3 as the exploratory cut-off for GTVnx, with an AUC of 0.709. Patients with high GTVnx had poorer OS than those with low GTVnx (log-rank P<0.001). In a multivariable Cox analysis, high GTVnx remained associated with poorer OS after adjustment for T stage and pretreatment Epstein-Barr virus DNA (EBV DNA; hazard ratio, 4.375; 95% confidence interval, 1.474-12.986; P=0.008). Adding GTVnx to the clinical model improved the C-index from 0.759 to 0.817, reduced the AIC from 135.151 to 133.085 and increased the 36-month AUC from 0.748 to 0.787. Sensitivity analyses supported the consistency of the main findings. GTVnx may provide supplementary prognostic information beyond T stage and pretreatment EBV DNA in patients with T3-4 NPC. However, the identified cut-off value and incremental prognostic value require validation in independent cohorts.