Résumé
Objective:To study the pathological changes of nasopharyngeal carcinoma cases after the treat-ment of stereotactic radiosurgery. Method: 15 cases with recurrent or residual squamous cell carcinoma of na-sopharynx diagnosed as T1~4 N0M0 were selected,which had undergone previous radiotherapy. The patients weretreated by Gamma Knife while the isodose curve was 50%00 and the margin dose was 20 Gy. The nasopharynxbiopsy was performed before the treatment and 1,3,6,12 months after the treatment. The biopsy specimen wastaken to make a pathological examination. Result:①Before the Gamma Knife treatment, carcinoma cell could beseen in the tissue;②1~3 months after the treatment, cell necrosis and acute inflammation cell infiltration couldbe seen in the target ;③6~12 months after the treatment ,infiltration of chronic inflammation cell ,proliferation offibrous tissue and capillary could be found in the target. Conclusion:This research implies that the short-termpathological changes after the treatment of stereotactic radiosurgery can be defined as two phases ..The first phaseoccurs from 1 to 3 months after the treatment called necrosis period. The second phase occurs from 6 to 12months after the Gamma Knife treatment named as absorption period.