title: Temporal Cerebral Microbleeds Are Associated With Radiation Necrosis and Cognitive Dysfunction in Patients Treated for Nasopharyngeal Carcinoma.
abstract: OBJECTIVE
  Radiation therapy for patients with nasopharyngeal carcinoma (NPC) may be complicated with radiation-induced brain necrosis (RN), resulting in deteriorated cognitive function. However, the underlying mechanism of this phenomenon remains unclear. This study attempts to elucidate the association between cerebral microbleeds (CMBs) and radiation necrosis and cognitive dysfunction in NPC patients treated with radiation therapy.
  
  
  METHODS
  This cross-sectional study included 106 NPC patients who were exposed to radiation therapy (78 patients with RN and 28 without RN). Sixty-six patients without discernable intracranial pathology were included as the control group. CMBs were confirmed using susceptibility-weighted magnetic resonance imaging. Cognitive function was accessed using Montreal Cognitive Assessment. Patients with a total score below 26 were defined as cognitively dysfunction.
  
  
  RESULTS
  Seventy-seven patients (98.7%) in the RN group and 12 patients (42.9%) in the non-RN group had at least 1 CMB. In contrast, only 14 patients (21.2%) in the control group had CMBs. In patients with a history of radiation therapy, CMBs most commonly presented in temporal lobes (76.4%) followed by cerebellum (23.7%). Patients with RN had more temporal CMBs than those in the non-RN group (37.7 ± 51.9 vs 3.8 ± 12.6, respectively; P<.001). The number of temporal lobe CMBs was predictive for larger volume of brain necrosis (P<.001) in multivariate linear regression analysis. Although cognitive impairment was diagnosed in 55.1% of RN patients, only 7.1% of non-RN patients sustained cognitive impairment (P<.001). After adjusting for age, sex, education, period after radiation therapy, CMBs in other lobes, and RN volume, the number of temporal CMBs remained an independent risk factor for cognitive dysfunction (odds ratio [OR]: 1.03; 95% confidence interval [CI]: 1.01-1.04; P=.003).
  
  
  CONCLUSIONS
  CMBs is a common radiological manifestation in NPC patients with RN. The number of temporal CMBs is independently associated with increased likelihood of cognitive dysfunction in patients with RN.
authors.affiliation: Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Department of Neurology, Zengcheng People's Hospital, Guangzhou, China.
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Shen
authors.affiliation: Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Focai
authors.initials: F
authors.lastname: Lin
authors.affiliation: Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Rong
authors.affiliation: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Wuyang
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Zhaoxi
authors.initials: Z
authors.lastname: Cai
authors.affiliation: Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Xu
authors.affiliation: Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Yongteng
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-sen University, Guangzhou, China; Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong Province, China. Electronic address: yameitang@hotmail.com.
authors.forename: Yamei
authors.initials: Y
authors.lastname: Tang
mesh_terms: D002277:Carcinoma; D016022:Case-Control Studies; D002531:Cerebellum / Q000098:blood supply / Q000473:pathology / Q000528:radiation effects; D002543:Cerebral Hemorrhage / Q000209:etiology*; D003072:Cognition Disorders / Q000209:etiology*; D004522:Educational Status; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000532:radiotherapy*; D009336:Necrosis / Q000150:complications / Q000175:diagnosis; D011446:Prospective Studies; D011832:Radiation Injuries / Q000150:complications* / Q000473:pathology; D012044:Regression Analysis; D013702:Temporal Lobe / Q000098:blood supply / Q000473:pathology / Q000528:radiation effects*