title: Computed tomographic findings of skull base bony changes after radiotherapy for nasopharyngeal carcinoma: implications for local recurrence.
abstract: OBJECTIVE
  To evaluate bony changes in the skull base after radiotherapy by computed tomography (CT) and their correlation with local recurrence in patients with nasopharyngeal carcinoma (NPC) without previous involvement of the skull base.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Sun-Yat Sen University Cancer Center.
  
  
  METHODS
  The records of 80 patients with NPC during the period from January 1992 to December 2005 were reviewed. All patients had been treated with radical radiotherapy or chemoradiotherapy at standard doses and were followed up with plain and contrast-enhanced CT every 6 months for 45.5 (range 12-108) months.
  
  
  METHODS
  The types, areas, time of the first occurrence after radiotherapy and development of the postradiation bony changes of the skull base, and local recurrence rates of NPC were measured.
  
  
  RESULTS
  Eighteen patients (22.5%) had sclerosis in some area of the skull base, and the sclerosis in 5 (27.8%) of these patients changed into osteoporosis in 1 to 5 years after its appearance. Seventeen patients (21.3%) had osteolysis. The local recurrence rate of patients with osteolysis was observed to be significantly higher than that of patients with sclerosis (p < .0001).
  
  
  CONCLUSIONS
  The appearance of osteolytic changes in the skull base during follow-up of patients with NPC who had normal skull base morphology before treatment was associated with tumour recurrence.
authors.affiliation: State Key Laboratory of Oncology in South China and Department of Medical Imaging and Interventional Radiology, Cancer Center, SunYat-Sen University, Guangzhou, Guangdong, PR China.
authors.forename: Chuan-Miao
authors.initials: CM
authors.lastname: Xie
authors.forename: Xue-Wen
authors.initials: XW
authors.lastname: Liu
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang
authors.forename: Yun-Xian
authors.initials: YX
authors.lastname: Mo
authors.forename: Jian-Peng
authors.initials: JP
authors.lastname: Li
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Geng
authors.forename: Lie
authors.initials: L
authors.lastname: Zheng
authors.forename: Yan-Chun
authors.initials: YC
authors.lastname: Lv
authors.forename: Pei-Hong
authors.initials: PH
authors.lastname: Wu
mesh_terms: D002277:Carcinoma; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D010014:Osteolysis / Q000000981:diagnostic imaging* / Q000209:etiology; D011379:Prognosis; D011832:Radiation Injuries / Q000000981:diagnostic imaging* / Q000209:etiology; D012189:Retrospective Studies; D019291:Skull Base / Q000000981:diagnostic imaging* / Q000528:radiation effects; D014057:Tomography, X-Ray Computed / Q000379:methods*