title: Variability in target delineation of cervical carcinoma: A Korean radiation oncology group study (KROG 15-06).
abstract: OBJECTIVE
  To determine inter-observer variability in target volume definition of cervical cancer in radical and adjuvant radiotherapy (RT) settings.
  
  
  METHODS
  Eight physicians contoured CTVs of 2 patients underwent definitive and postoperative RT. Each volume was analyzed using the individual/median volume ratio and generalized conformity index (CIgen). And center of mass (COM) of each contour was calculated. Expert agreement was quantified using an expectation maximization algorithm for Simultaneous Truth and Performance Level Estimation (STAPLE).
  
  
  RESULTS
  For definitive RT, the individual/median volume ratio ranged from 0.51 to 1.41, and CIgen was 0.531. Mean 3-dimensional distances of average to each COM were 7.8 mm. For postoperative RT setting, corresponding values were 0.65-1.38, 0.563, and 5.3 mm. Kappa value of expert agreement was 0.65 and 0.67, respectively. STAPLE estimates of the sensitivity, specificity, and kappa measures of inter-physician agreement were 0.73, 0.98, and 0.65 for the definitive and 0.75, 0.98, and 0.67 for the adjuvant radiotherapy setting. The largest difference was observed in the superior-inferior direction, particularly in the upper vagina and the common iliac area.
  
  
  CONCLUSIONS
  As there was still some variability in target delineation, more detailed guidelines for target volume delineation and continuing education would help to reduce this uncertainty.
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, Republic of Korea.
authors.forename: Ji Hyeon
authors.initials: JH
authors.lastname: Joo
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, Republic of Korea.
authors.forename: Young Seok
authors.identifier: http://orcid.org/0000-0003-4739-4476
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, Republic of Korea.
authors.forename: Byung Chul
authors.initials: BC
authors.lastname: Cho
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, Republic of Korea.
authors.forename: Chi Young
authors.initials: CY
authors.lastname: Jeong
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Won
authors.initials: W
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Hak Jae
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Korea University Ansan Hospital, Ansan, Gyeonggi-do, Republic of Korea.
authors.forename: Won Sup
authors.initials: WS
authors.lastname: Yoon
authors.affiliation: Department of Radiation Oncology, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Hwasun, Jeollanam-do, Republic of Korea.
authors.forename: Mee Sun
authors.initials: MS
authors.lastname: Yoon
authors.affiliation: Department of Radiation Oncology, the Catholic University of Korea, College of Medicine, Seoul, Republic of Korea.
authors.forename: Ji-Yoon
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Chung-Ang University Hospital, Seoul, Republic of Korea.
authors.forename: Jin Hwa
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Radiation Oncology, Dong-A University Hospital, Busan, Republic of Korea.
authors.forename: Youngmin
authors.initials: Y
authors.lastname: Choi
authors.affiliation: Center for Uterine Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi-do, Republic of Korea.
authors.forename: Joo-Young
authors.initials: JY
authors.lastname: Kim
mesh_terms: D005260:Female; D006801:Humans; D018714:Radiotherapy, Adjuvant; D056910:Republic of Korea; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy*