[The pathological changes of XXXX cases treated by stereotactic radiosurgery].

@entity1 @entity32 @entity39 @entity957 @entity189
OBJECTIVE: To study the pathological changes of @entity189 cases after the treatment of stereotactic radiosurgery. METHOD: 15 cases with recurrent or residual @entity957 of nasopharynx diagnosed as T1-4 N0M0 were selected, which had undergone previous radiotherapy. The @entity1 were treated by Gamma Knife while the isodose curve was 50% and the margin dose was 20 Gy. The nasopharynx biopsy was performed before the treatment and 1, 3, 6, 12 months after the treatment. The biopsy specimen was taken to make a pathological examination. RESULT: 1. Before the Gamma Knife treatment, @entity189 cell could be seen in the tissue; 2. 1-3 months after the treatment, cell @entity39 and acute @entity32 cell infiltration could be seen in the target; 3. 6-12 months after the treatment, infiltration of chronic @entity32 cell, proliferation of fibrous tissue and capillary could be found in the target. CONCLUSION: This research implies that the short-term pathological changes after the treatment of stereotactic radiosurgery can be defined as two phases: The first phase occurs from 1 to 3 months after the treatment called @entity39 period. The second phase occurs from 6 to 12 months after the Gamma Knife treatment named as absorption period.
