title: Three-dimensional analysis of patterns of locoregional recurrence after treatment in breast cancer patients: Validation of the ESTRO consensus guideline on target volume.
abstract: To explore the validity of the ESTRO-clinical target volume (CTV), we conducted three-dimensional analyses of locoregional recurrence (LRR) patterns according to the ESTRO- and RTOG-CTVs. Moreover, we explored which factors contribute to metastasis development outside the recommended CTV.
  
  
  
  We identified patients with post-treatment LRR explicitly exhibited on computed tomography (CT) images. All recurrences on CT were overlaid on representative CT images at the equivalent location, based on reference anatomic structures.
  
  
  
  A total of 235 recurrent lesions were identified in 129 patients. We depicted all LRR patterns in relation to the ESTRO- and RTOG-CTVs on CT and maximum intensity projection images. The ESTRO-CTV successfully contained the extent of the LRR within the RTOG-CTV in 96.4% of all early-stage breast-conserved women. Geographic misses of local recurrence were frequently observed in mastectomy patients (P=.002) and tended to originate from deep, but thin, chest walls. The rate of geographic misses of regional recurrence was low (3.6%) at the early stage, but increased in patients aged <45years and with triple-negative tumors (P<.05).
  
  
  
  Application of the ESTRO-CTV in early-stage disease seems justified.
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Jee Suk
authors.initials: JS
authors.lastname: Chang
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Hwa Kyung
authors.initials: HK
authors.lastname: Byun
authors.affiliation: Department of Radiation Oncology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Jun Won
authors.initials: JW
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea; Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South 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, South Korea.
authors.forename: Yeona
authors.initials: Y
authors.lastname: Cho
authors.affiliation: Department of Radiation Oncology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Ik Jae
authors.initials: IJ
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Ki Chang
authors.initials: KC
authors.lastname: Keum
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Chang-Ok
authors.initials: CO
authors.lastname: Suh
authors.affiliation: Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, South Korea. Electronic address: ybkim3@yuhs.ac.
authors.forename: Yong Bae
authors.initials: YB
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D032921:Consensus; D005260:Female; D006801:Humans; D008408:Mastectomy; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D017410:Practice Guidelines as Topic; D014057:Tomography, X-Ray Computed / Q000379:methods*; D047368:Tumor Burden
keywords: Breast cancer; CTV; ESTRO; RTOG; Recurrence patterns; Supraclavicular lymph nodes