title: Radiation Pneumonitis in Association with Internal Mammary Node Irradiation in Breast Cancer Patients: An Ancillary Result from the KROG 08-06 Study.
abstract: OBJECTIVE
  The aim of this study is to present the incidence of radiation pneumonitis (RP) reported within 6 months after treatment for breast cancer with or without internal mammary node irradiation (IMNI).
  
  
  METHODS
  In the Korean Radiation Oncology Group (KROG) 08-06 phase III randomized trial, patients who were node-positive after surgery were randomly assigned to receive radiotherapy either with or without IMNI. A total of 747 patients were enrolled, and three-dimensional treatment planning with computed tomography simulation was performed for all patients. Of the 747 patients, 722 underwent chest X-rays before and within 6 months after radiotherapy. These 722 patients underwent evaluation, and RP was diagnosed on the basis of chest radiography findings and clinical symptoms. The relationship between the incidence of RP and clinical/dosimetric parameters was analyzed.
  
  
  RESULTS
  RP developed in 35 patients (4.8%), including grade 1 RP in 26 patients (3.6%), grade 2 RP in nine patients (1.2%); there was no incidence of grade 3 or higher RP. Grade 2 RP cases were observed in only the IMNI group. The risk of developing RP was influenced by IMNI treatment; pneumonitis occurred in 6.5% of patients (n=23/356) who underwent IMNI and in 3.3% of patients (n=12/366) who did not (p=0.047). The differences in lung dosimetric parameters (mean lung dose, V10-40) were statistically significant between the two groups.
  
  
  CONCLUSIONS
  IMNI treatment resulted in increased radiation exposure to the lung and a higher rate of RP, but the incidence and severity of RP was minimal and acceptable. This minor impact on morbidity should be balanced with the impact on survival outcome in future analyses.
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, 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, Korea.
authors.forename: Yong Bae
authors.initials: YB
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Shin
authors.affiliation: Department of Radiation Oncology, Chonnam National University Hwasun Hospital, Hwasun, Korea.
authors.forename: Sung-Ja
authors.initials: SJ
authors.lastname: Ahn
authors.affiliation: Department of Radiation Oncology, Dong-A University Hospital, Dong-A University College of Medicine, Busan, Korea.
authors.forename: Hyung-Sik
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Won
authors.initials: W
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Su Ssan
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Gachon University Gil Medical Center, Incheon, Korea.
authors.forename: Kyu Chan
authors.initials: KC
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Dong Won
authors.initials: DW
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Ewha Womans University Mokdong Hospital, Seoul, Korea.
authors.forename: Hyun Suk
authors.initials: HS
authors.lastname: Suh
authors.affiliation: Department of Radiation Oncology, Ewha Womans University Mokdong Hospital, Seoul, Korea.
authors.forename: Kyung Ran
authors.initials: KR
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, CHA Bundang Hospital, CHA University College of Medicine, Seongnam, Korea.
authors.forename: Hyun Soo
authors.initials: HS
authors.lastname: Shin
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Chang-Ok
authors.initials: CO
authors.lastname: Suh
keywords: Breast neoplasms; Lymphatic irradiation; Radiation pneumonitis