Influence of MRI on the Chinese 1992 staging system of nasopharyngeal carcinoma (NPC) / 中国癌症杂志

ABSTRACT

Purpose:To investigate the influence of MRI on the Chinese 1992 staging system of nasopharyngeal carcinoma(NPC).Methods:From Oct.1992 to Jan.1996,86 patients with NPC who had MRI and CT prior to radiotherapy were retrospectively analyzed.The total dose to the primary tumor was 60.4～85.0 Gy(median,72.5 Gy).The fractionation schedule used was five daily fractions of 1.8～2.0 Gy per week.The survival rates were estimated by the Kaplan-Meier method.Log-rank was used to identify the prognostic factors.Results:The loco-regional control rate at 5 year was 84.2%,distant metastasis-free survival 80.1%,disease-free survival 73.9% and overall survival 82.7% with a median follow-up interval of 65.5 months(range 2～108 months).According to the Chinese 1992 staging system,there were 25 vs 14(25 by CT and 14 by MRI) patients with T_(1),21 vs 8 with T_(2),31 vs 42 with T_(3) and 9 vs 22 with T_(4) lesions.As a result,42.9%(12/28) of cervical nodal and 28.6%(8/28) of retropharyngeal lymphadenopathy alone should downstage from N_(0) to N_(1).Conclusions:The influence of MRI on the Chinese 1992 staging system was significant and the authors observed a worse distribution of patient numbers as well as poorer separation of survival curves among different stage groups.