title: The stratification of severity of acute radiation proctopathy after radiotherapy for cervical carcinoma using diffusion-weighted MRI.
abstract: OBJECTIVE
  To determine whether diffusion-weighted imaging (DWI) can be used for quantitatively evaluating severity of acute radiation proctopathy after radiotherapy for cervical carcinoma.
  
  
  METHODS
  One hundred and twenty-four patients with cervical carcinoma underwent MR examination including DWI before and after radiotherapy. Acute radiation proctopathy was classified into three groups (grade 0, grade I-II and grade III-IV) according to Toxicity Criteria of the Radiation Therapy Oncology Group (RTOG). The pretreatment ADC (ADCpre), ADC after treatment (ADCpost) and ADC change (ΔADC) were compared among three groups. In addition, acute radiation proctopathy was classified into good-prognosis group and poor-prognosis group. ADCpre, ADCpostand ΔADC were compared between two groups. For DWI parameter that had significant difference, discriminatory capability of the parameter was determined using receiver operating characteristics (ROC) analysis.
  
  
  RESULTS
  ADCpostand ΔADC were higher in grade I-II group than in grade 0 group (p<0.05), yielding a sensitivity of 79.3% and specificity of 69.4% for ADCpost, and 85.1%, 72.3% for ΔADC for discrimination between two groups. ADCpostand ΔADC were higher in grade III-IV group than in grade I-II group (p<0.05), yielding a sensitivity of 80.3% and specificity of 72.5% for ADCpost, and 84.1%, 74.5% for ΔADC for discrimination between two groups. ADCpostand ΔADC were higher in poor-prognosis group than in good-prognosis group (p<0.05), yielding a sensitivity of 79.5% and specificity of 73.4% for ADCpost, and 87.2%, 78.3% for ΔADC for discrimination between two groups.
  
  
  CONCLUSIONS
  Diffusion-weighted MRI can be used for quantitative stratification of severity of acute radiation proctopathy, which serves as an important basis for appropriate timely adjustment of radiotherapy for cervical carcinoma in order to maximally reduce the radiation injury of rectum.
authors.affiliation: Department of Radiology, Air Force General Hospital of People's Liberation Army, Beijing 100142, China. Electronic address: lxsheng500@163.com.
authors.forename: Xiang Sheng
authors.initials: XS
authors.lastname: Li
authors.affiliation: Department of Radiology, Air Force General Hospital of People's Liberation Army, Beijing 100142, China. Electronic address: hongfang196808@sina.com.
authors.forename: Hong
authors.initials: H
authors.lastname: Fang
authors.affiliation: Department of Radiology, Air Force General Hospital of People's Liberation Army, Beijing 100142, China. Electronic address: yunlongsong010@sina.com.
authors.forename: Yunlong
authors.initials: Y
authors.lastname: Song
authors.affiliation: Department of Pathology, Air Force General Hospital of People's Liberation Army, Beijing 100142, China. Electronic address: dechangli1972@sina.com.
authors.forename: Dechang
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Radiotherapy, Air Force General Hospital of People's Liberation Army, Beijing 100142, China. Electronic address: wangyj19710813@sina.com.
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Radiology, Air Force General Hospital of People's Liberation Army, Beijing 100142, China. Electronic address: hongxian0102@sina.cn.
authors.forename: Hongxian
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Department of Radiology, Air Force General Hospital of People's Liberation Army, Beijing 100142, China. Electronic address: liminmeng1977@sina.com.
authors.forename: Limin
authors.initials: L
authors.lastname: Meng
authors.affiliation: Department of Radiology, Air Force General Hospital of People's Liberation Army, Beijing 100142, China. Electronic address: pingwang1978@sina.com.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Radiology, Air Force General Hospital of People's Liberation Army, Beijing 100142, China. Electronic address: dongwang1964@sina.com.
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Radiology, Air Force General Hospital of People's Liberation Army, Beijing 100142, China. Electronic address: fanhongxia1975@sina.com.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Fan
mesh_terms: D000328:Adult; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008875:Middle Aged; D012372:ROC Curve; D011832:Radiation Injuries / Q000000981:diagnostic imaging*; D012007:Rectum / Q000000981:diagnostic imaging* / Q000528:radiation effects*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy*
keywords: Acute radiation proctopathy; Cervical carcinoma; Diffusion-weighted imaging (DWI); Severity; Stratification