| Purpose:To study the natural course and outcome of the residual diseases in the nasopharynx based on fiberoptic endoscope after NPC receiving IMRT and to evaluate the prognostic significance of residual lesions.Methods:From November 2014,to March 2018,the residual diseases in the nasopharynx based on fiberoptic endoscope after NPC receiving IMRT were divided into three types:mucous membrane coarse.elevated mucosa and neoplasm.The residual diseases stilled existed one month,three months and six months after radiotherapy were dynamically observed and examed by direct vision biopsy and pathological examination.The pathological results were classified as three types:inflammation,positive with radiation change in tumor cells and positive for malignancy.Kaplan-Meier model was used to calculate OS,LPFS,LRRFS,PFS,DMFS of each patient group and log-rank test was used to make comparison between each group.Cox proportional hazards models were used to do multi-factor analysis to Identify independent prognostic factors.Only when P<0.05 the results would have statistics significance.Result:1.There are 132 cases of NPC patients at one month after radiotherapy who had suspicious residual diseases,among which the numbers of cases for mucous membrane coarse,elevated mucosa,neoplasm are 43,29 and 60 respectively,and the ratios of the incidences of cancer tissue identified through biopsy pathology for these three types are 11.6%,10.3%and 21.7%respectively.The difference is not statistically significant(X2=3.79,P=0.435).2.The numbers of patients in 132 cases whose pathological type of residual diseases are identified as inflammation,positive with radiation change in tumor cells and positive for malignancy at one month after radiotherapy were 71,40 and 21 respectively.There was no significant difference in prognosis in three patient groups.Cancer patients were only regarded as Pathologically positive group.The local control of the pathologically(+)is worse than pathologically(-)and the three-year’ s LRFS of two groups were 78.5%and 94.0%,(P=0.034).3.At three months after radiotherapy,there were 92.4%patients(122/132)whose residual diseases disappeared.The remaining 10 patients still had suspicious residual diseases,among which one case of elevated mucosa was Inflammatory necrotic tissue,the remaining nine cases were neoplasm membrane coarse,including three cases whose pathological types are positive with radiation change in tumor cells and six cases whose pathological types are inflammation.4.The results of univariate analysis show:T stage is related to OS,LRFS,LRRFS.PFS,and DMFS;N stage,clinical stage,initial EBV-DNA level have close relationship with PFS and DMFS;Age and pathological type at one month after radiotherapy are closely related to LRFS;Concurrent chemotherapy is related to OS;The results of multivariate analysis show:Clinical stage and initial EBV-DNA levelare the independent prognostic factors of PFS;Late T stage and 1 month after radiotherapy are the Independent adverse prognostic factors of LRFS.Conclusion:After the intensity-modulated radiotherapy of nasopharyngeal carcinoma,it is not reliable to judge the residue Under the fiberoptic endoscope because most of the lesions will naturally disappear and most of them are not phathologically residual.However if the phathological type is cancer tissue at one month after radiotherapy,then the local recurrence rate will be high.Late T stage and the cancer tissue at one month after radiotherapy are the independent adverse prognostic factors of LRFS;Clinical stage and initial EBV-DNA levelare the independent prognostic factors of PFS. |
