[目的]探讨腔内放疗对鼻咽癌外照射后鼻咽腔内未消退病灶的治疗效果 ,研究近距离放疗时8个剂量参照点的剂量分布及其影响因素。[方法]1994年4月至1998年11月共对34例鼻咽癌外照射后鼻咽腔内未消退病灶行高剂量率近距离放疗(外照射剂量60Gy～71Gy,外照射结束后2天～5天进行首次治疗 ,多数病例剂量参考点深度1 0cm ,放射源驻留长度2 0cm～3 5cm ,多数病例单次剂量8Gy、总剂量16Gy/2次。[结果]CR38例(38/39,97 4 %) ,PR1例(1/39,2 6%) ,中位随访期17月 ,无严重副作用发生 ,通过计算明确了8个参照点的剂量分布情况。[结论]腔内放疗是控制鼻咽腔内外照射后未消退病灶的有效治疗方法 ,但应注意适应证 [Objective] To investigate the therapeutic effect of intracavitary radiotherapy on undifferentiated lesions in nasopharyngeal cavity after external irradiation of nasopharyngeal carcinoma and to study the dose distribution and its influencing factors of 8 dose reference points in brachytherapy. [Methods] From April 1994 to November 1998, 34 cases of nasopharyngeal carcinoma outside the nasopharynx were irradiated with high dose rate brachytherapy (external dose 60Gy ~ 71Gy, 2 days after the end of external irradiation ~ 5 days for the first time treatment, most cases dose reference point depth 10cm, radioactive reside length 20cm ~ 35cm, the majority of cases a single dose of 8Gy, total dose of 16Gy / 2 times. [Results] CR38 cases (38/39 , 97 4%), PR1 cases (1 / 39,26%), the median follow-up period of 17 months, no serious side effects occurred, calculated by the calculation of the 8 reference point dose distribution. [Conclusion] Control of nasopharyngeal cavity before and after irradiation does not resolve the effective treatment of lesions, but should pay attention to indications