title: [The pathological changes of nasopharyngeal carcinoma cases treated by stereotactic radiosurgery].
abstract: OBJECTIVE
  To study the pathological changes of nasopharyngeal carcinoma cases after the treatment of stereotactic radiosurgery.
  
  
  METHODS
  15 cases with recurrent or residual squamous cell carcinoma of nasopharynx diagnosed as T1-4 N0M0 were selected, which had undergone previous radiotherapy. The patients 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.
  
  
  RESULTS
  1. Before the Gamma Knife treatment, carcinoma cell could be seen in the tissue; 2. 1-3 months after the treatment, cell necrosis and acute inflammation cell infiltration could be seen in the target; 3. 6-12 months after the treatment, infiltration of chronic inflammation cell, proliferation of fibrous tissue and capillary could be found in the target.
  
  
  CONCLUSIONS
  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 necrosis period. The second phase occurs from 6 to 12 months after the Gamma Knife treatment named as absorption period.
authors.affiliation: Department of Otolaryngology, Huashan Hospital, Shanghai Medical University, Shanghai 200040.
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Hu
authors.forename: R H
authors.initials: RH
authors.lastname: Dong
authors.forename: Z W
authors.initials: ZW
authors.lastname: Zhou
authors.forename: J Z
authors.initials: JZ
authors.lastname: Dai
authors.forename: L
authors.initials: L
authors.lastname: Pan
authors.forename: B J
authors.initials: BJ
authors.lastname: Wang
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000473:pathology* / Q000601:surgery; D009364:Neoplasm Recurrence, Local / Q000601:surgery*; D016634:Radiosurgery / Q000379:methods*; D013238:Stereotaxic Techniques