title: The value of endoscopic ultrasonography in defining longitudinal gross target volumes for esophageal squamous carcinoma.
abstract: OBJECTIVE
  To investigate the differences between endoscopic ultrasonography (EUS)-based longitudinal gross target volumes (GTV) (GTV(EUS)) and computed tomography (CT)-based longitudinal GTV (GTV(CT)) in diagnosing esophageal squamous carcinoma.
  
  
  METHODS
  Thirty-six patients underwent EUS to define the superior and inferior extents of the tumor by using hemoclips. CT-planning scan was performed with the patient in the supine position during the treatment. GTV(CT) and GTV(EUS) were contoured respectively. The respective lengths (L(CT) and L(EUS)) and spatial locations of longitudinal GTV(CT) and longitudinal GTV(EUS) were compared.
  
  
  RESULTS
  The mean LCT was 7.8 ± 3.2 cm and the mean L(EUS) was 7.4 ± 2.7 cm. No statistical difference was found between L(CT) and L(EUS) (P > 0.05) with a correlation coefficient of 0.61 (P<0.05). The mean conformal index was 0.79 ± 0.18 with spatial variations found in 71% (24/34) of the patients.
  
  
  CONCLUSIONS
  EUS can provide additional information to CT in defining longitudinal GTV in thoracic esophageal squamous cell carcinoma, especially superficial and submucosal carcinomas, which may contribute to the development of better individual treatment regimens.
authors.affiliation: Department of Radiation Oncology and Radiotherapy, Zhejiang Cancer Hospital, Hangzhou, China.
authors.forename: Guo-qin
authors.initials: GQ
authors.lastname: Qiu
authors.forename: Xiang-hui
authors.initials: XH
authors.lastname: Du
authors.forename: Jiang-ping
authors.initials: JP
authors.lastname: Yu
authors.forename: Yuan-da
authors.initials: YD
authors.lastname: Zheng
authors.forename: Hao-Jie
authors.initials: HJ
authors.lastname: Luo
authors.forename: Ya-ping
authors.initials: YP
authors.lastname: Xu
authors.forename: Jian-xiang
authors.initials: JX
authors.lastname: Chen
authors.forename: Xiao-Jiang
authors.initials: XJ
authors.lastname: Sun
authors.forename: Yong-ling
authors.initials: YL
authors.lastname: Ji
authors.forename: Ya-li
authors.initials: YL
authors.lastname: Tao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D019160:Endosonography; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D004945:Esophagoscopy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*