Analysis of predictive factors of parameters related to severe oral mucositis during intensity modulated radiotherapy for nasopharyngeal carcinoma
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 V35,T stage,age and induced chemotherapy cycles of NPC patients after IMRT were independent predictors of SOM.The NTCP model was S=-16.220+(V35×0.059)+(T stage×0.655)+(age×0.083)+(induced chemotherapy cycles×0.537).Based on V35 fitted volume-response curve,the fitting parameters included T stage,age and induced chemotherapy cycles.When the V35 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 V35,which can be a reliable indicator for predicting the risk of SOM in NPC patients after radiotherapy.
Nasopharyngeal carcinomaDosimetric parametersSevere oral mucositisIntensity modulated radiotherapyNormal tissue complication probability model
NETL
NSTL
万方数据
