title: Individual case review in a phase 3 randomized trial to investigate the role of internal mammary lymph node irradiation for breast cancer: Korean Radiation Oncology Group 08-06 study.
abstract: This study aimed to assess protocol compliance based on an individual case review (ICR) of the Korean Radiation Oncology Group-0806 trial.
  
  
  
  For the ICR, 747 participants were divided into eight subgroups based on internal mammary node irradiation (IMNI), tumor laterality, and surgery type. Next, 15% of patients were randomly selected within each subgroup, and corresponding hospitals were subsequently requested to upload information related to radiation therapy (RT) planning. We reviewed the dose distributions of targets and organs at risk to determine protocol compliance.
  
  
  
  Data of 102 patients were collected. Overall, RT plans were found to be mostly protocol-compliant, with acceptability rates of 60-80% despite deviations in the ipsilateral lung in Arm 2 (IMNI group). However, despite few deviations, a subgroup analysis revealed significant differences in protocol compliance. Among RT techniques, plans using standard and partial wide tangents were most compliant in both Arms. In this ICR, the estimated survival benefits based on IMN doses were 7.7%, 8.4%, and 7.2% for all, breast-conserving surgery, and mastectomy cases, respectively.
  
  
  
  This ICR demonstrated overall protocol compliance, despite significant differences with regard to IMN irradiation and organs at risk according to subgroups and adopted field arrangements.
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Hong In
authors.initials: HI
authors.lastname: Yoon
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jeongmin
authors.initials: J
authors.lastname: Yoon
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Seoul, Republic of Korea.
authors.forename: Yoonsun
authors.initials: Y
authors.lastname: Chung
authors.affiliation: Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Chung Mo
authors.initials: CM
authors.lastname: Nam
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Seoul, Republic of Korea.
authors.forename: Hyejung
authors.initials: H
authors.lastname: Cha
authors.affiliation: Department of Radiation Oncology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jinhyun
authors.initials: J
authors.lastname: Choi
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jeongshim
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Hee Ji
authors.initials: HJ
authors.lastname: Han
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Yeona
authors.initials: Y
authors.lastname: Cho
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea. Electronic address: ybkim3@yuhs.ac.
authors.forename: Yong Bae
authors.initials: YB
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Chang-Ok
authors.initials: CO
authors.lastname: Suh
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology / Q000528:radiation effects*; D015182:Lymphatic Irradiation / Q000379:methods*; D008408:Mastectomy; D015412:Mastectomy, Segmental; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: Individual cases review; Internal mammary node irradiation; Protocol-compliance; Radiation therapy quality assurance