title: Evaluation of variability in target volume delineation for newly diagnosed glioblastoma: a multi-institutional study from the Korean Radiation Oncology Group.
abstract: BACKGROUND
  This study aimed for a collaborative evaluation of variability in the target volumes for glioblastoma, determined and contoured by different radiotherapy (RT) facilities in Korea.
  
  
  METHODS
  Fifteen panels of radiation oncologists from independent institutions contoured the gross target volumes (GTVs) and clinical target volumes (CTVs) for 3-dimensional conformal RT or intensity-modulated RT on each simulation CT images, after scrutinizing the enhanced T1-weighted and T2-weighted-fluid-attenuated inversion recovery MR images of 9 different cases of glioblastoma. Degrees of contouring agreement were analyzed by the kappa statistics. Using the algorithm of simultaneous truth and performance level estimation (STAPLE), GTVSTAPLE and CTVSTAPLE contours were derived.
  
  
  RESULTS
  Contour agreement was moderate (mean kappa 0.58) among the GTVs and was substantial (mean kappa 0.65) among the CTVs. However, each panels' GTVs and modification of CTVs regarding anatomical structures varied. Three-fourth of contoured panels' CTVs encompassed the peritumoral areas of T2-high signal intensity (T2-HSI). Nine of nine GTVSTAPLE encompased the surgical cavity and the T1-enhanced lesions. Eight of nine CTVSTAPLE encompassed the peritumoral T2-HSI area. The median MARGIN90 and the median MARGIN95 were 1.4 cm and 1.5 cm, respectively.
  
  
  CONCLUSIONS
  Moderate to substantial agreement existed in target volumes for 3-dimensional or intensity-modulated RT determined by radiation oncologists in Korea. According to the estimated consensus contours, the initial CTV encompassed the GTV with margin less than 2.0 cm and the whole peritumoral areas of T2-HSI. The findings of our study propose the need for further studies and modified guidelines.
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea. wcw0108@hanmail.net.
authors.forename: Chan Woo
authors.initials: CW
authors.lastname: Wee
authors.affiliation: Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea. s1moremore@gmail.com.
authors.forename: Wonmo
authors.initials: W
authors.lastname: Sung
authors.affiliation: Dongnam Institute of Radiological and Medical Sciences, Busan, Korea. hermes-shule@hanmail.net.
authors.forename: Hyun-Cheol
authors.initials: HC
authors.lastname: Kang
authors.affiliation: Research Institute and Hospital, National Cancer Center, Gyeonggi-do, Korea. kwancho@ncc.re.kr.
authors.forename: Kwan Ho
authors.initials: KH
authors.lastname: Cho
authors.affiliation: Hallym University Kangdong Sacred Heart Hospital, Seoul, Korea. hantz@hanmail.net.
authors.forename: Tae Jin
authors.initials: TJ
authors.lastname: Han
authors.affiliation: Gyeongsang National University Hospital, Gyeongsangnam-do, Korea. blue129j@hanmail.net.
authors.forename: Bae-Kwon
authors.initials: BK
authors.lastname: Jeong
authors.affiliation: Chonnam National University Hwasun Hospital, Jeollanam-do, Korea. ramachka@naver.com.
authors.forename: Jae-Uk
authors.initials: JU
authors.lastname: Jeong
authors.affiliation: Hallym University Dongtan Sacred Heart Hospital, Gyeonggi-do, Korea. pumpkin0131@hanmail.net.
authors.forename: Haeyoung
authors.initials: H
authors.lastname: Kim
authors.affiliation: Seoul National University Bundang Hospital, Gyeonggi-do, Korea. inah228@snu.ac.kr.
authors.forename: In Ah
authors.initials: IA
authors.lastname: Kim
authors.affiliation: Keimyung University Dongsan Medical Center, Daegu, Korea. jhkim@dsmc.or.kr.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Kim
authors.affiliation: St. Vincent's Hospital, The Catholic University of Korea College of Medicine, Gyeonggi-do, Korea. kimandre@catholic.ac.kr.
authors.forename: Sung Hwan
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Seoul National University Boramae Medical Center, Seoul, Korea. kimsuzy@hanmail.net.
authors.forename: Suzy
authors.initials: S
authors.lastname: Kim
authors.affiliation: Uijeongbu St. Mary's Hospital, The Catholic University of Korea College of Medicine, Gyeonggi-do, Korea. dreamdoc77@catholic.ac.kr.
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Lee
authors.affiliation: Hallym University Sacred Heart Hospital, Gyeonggi-do, Korea. mylee@hallym.or.kr.
authors.forename: Me Yeon
authors.initials: MY
authors.lastname: Lee
authors.affiliation: Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. dh8lim@skku.edu.
authors.forename: Do Hoon
authors.initials: DH
authors.lastname: Lim
authors.affiliation: Jeonju Jesus Hospital, Jeollabuk-do, Korea. mint-berry@hanmail.net.
authors.forename: Hye Li
authors.initials: HL
authors.lastname: Park
authors.affiliation: Yonsei University College of Medicine, Seoul, Korea. COSUH317@yuhs.ac.
authors.forename: Chang-Ok
authors.initials: CO
authors.lastname: Suh
authors.affiliation: Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. drsmyoon@amc.seoul.kr.
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Yoon
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea. ihkim@snu.ac.kr.|Cancer Research Institute; Institute of Radiation Medicine, Seoul National University College of Medicine, 101 Daehak-ro Jongno-gu, Seoul, 110-744, Korea. ihkim@snu.ac.kr.
authors.forename: Il Han
authors.initials: IH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D001929:Brain Edema / Q000000981:diagnostic imaging / Q000209:etiology; D001932:Brain Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D005909:Glioblastoma / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D016013:Likelihood Functions; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D018787:Radiation Oncology / Q000458:organization & administration; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods / Q000592:standards; D020266:Radiotherapy, Conformal; D061089:Radiotherapy, Image-Guided; D050397:Radiotherapy, Intensity-Modulated; D015203:Reproducibility of Results; D056910:Republic of Korea; D014057:Tomography, X-Ray Computed / Q000379:methods*; D047368:Tumor Burden; D055815:Young Adult