鼻咽癌调强放疗期间重度口腔黏膜炎相关参数的预测因素分析

Analysis of predictive factors of parameters related to severe oral mucositis during intensity modulated radiotherapy for nasopharyngeal carcinoma

目的探讨接受调强放疗(IMRT)的鼻咽癌患者发生严重口腔黏膜炎(SOM)的影响因素,建立预测SOM的正常组织并发症概率(NTCP)模型并进行验证。方法对2021年6月至2022年3月接受评估和治疗的95例鼻咽癌患者的临床变量和辐射剂量学参数进行回顾性分析。使用基于最小绝对值收缩和选择算子(LASSO)回归模型建立NTCP模型,确定SOM的最佳预测因素。建立单变量截止剂量NTCP模型,以确定剂量-体积限制,并对NTCP模型的辨别能力进行评价。结果95例患者中有43例(45.3%)出现SOM。利用LASSO法筛选变量,IMRT后鼻咽癌患者V 35、T分期、年龄和诱导化疗周期数是影响SOM的独立预测因素(P<0.05)。NTCP模型为S=-16.220+(V_(35)×0.059)+(T分期×0.655)+(年龄×0.083)+(诱导化疗周期数×0.537)。基于V 35拟合体积-反应曲线,拟合参数包括T分期、年龄、诱导化疗周期数,当鼻咽癌患者口腔黏膜V 35约为44.5%时,SOM风险为50.0%。NTCP的受试者工作特征曲线下面积为0.89(95%CI:0.83~0.96)。结论本研究建立并验证了预测SOM的NTCP模型,尤其是V 35,可用于预测鼻咽癌患者放疗后SOM的发病风险。

Objective To determine the risk factors for severe oral mucositis(SOM)in nasopharyngeal carcinoma(NPC)patients receiving intensity modulated radiotherapy(IMRT),and to establish and validate a normal tissue complication probability(NTCP)model for predicting SOM.Methods Retrospective analysis was done on the clinical variables and radiation dosimetric parameters of 95 NPC patients from June 2021 to March 2022.The best predictors of SOM were determined using the NTCP model based on the minimum absolute contraction and selection operator(LASSO).A univariate cut-off dose NTCP model was established to determine dose-volume limits.The discrimination ability of the NTCP model was further evaluated.Results SOM toxicity was found in 43(45.3%)of 95 patients.LASSO method was used to screen variables,and the result showed that V 35,T stage,age and induced chemotherapy cycles of NPC patients after IMRT were independent predictors of SOM.The NTCP model was S=-16.220+(V_(35)×0.059)+(T stage×0.655)+(age×0.083)+(induced chemotherapy cycles×0.537).Based on V 35 fitted volume-response curve,the fitting parameters included T stage,age and induced chemotherapy cycles.When the V 35 of oral mucosa of NPC patients was about 44.5%,and the SOM risk was 50.0%.The area under the receiver operating characteristic curve of NTCP was 0.89(95%CI:0.83-0.96).Conclusion The study has established and verified the NTCP model for predicting SOM,especially V 35,which can be a reliable indicator for predicting the risk of SOM in NPC patients after radiotherapy.