title: Recommendations from GEC ESTRO Breast Cancer Working Group (I): Target definition and target delineation for accelerated or boost Partial Breast Irradiation using multicatheter interstitial brachytherapy after breast conserving closed cavity surgery.
abstract: OBJECTIVE
  The aim was to develop a delineation guideline for target definition for APBI or boost by consensus of the Breast Working Group of GEC-ESTRO.
  Appropriate delineation of CTV (PTV) with low inter- and intra-observer variability in clinical practice is complex and needs various steps as: (1) Detailed knowledge of primary surgical procedure, of all details of pathology, as well as of preoperative imaging. (2) Definition of tumour localization before breast conserving surgery inside the breast and translation of this information in the postoperative CT imaging data set. (3) Calculation of the size of total safety margins. The size should be at least 2 cm. (4) Definition of the target. (5) Delineation of the target according to defined rules.
  
  
  CONCLUSIONS
  Providing guidelines based on the consensus of a group of experts should make it possible to achieve a reproducible and consistent definition of CTV (PTV) for Accelerated Partial Breast Irradiation (APBI) or boost irradiation after breast conserving closed cavity surgery, and helps to define it after selected cases of oncoplastic surgery.
authors.affiliation: Department of Radiation Oncology, University Hospital Erlangen, Germany. Electronic address: vratislav.strnad@uk-erlangen.de.
authors.forename: Vratislav
authors.initials: V
authors.lastname: Strnad
authors.affiliation: Department of Radiation Oncology, Centre Antoine Lacassagne, Nice, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Hannoun-Levi
authors.affiliation: Department of Radiation Oncology, Fundación Instituto Valenciano de Oncología, Valencia, Spain.
authors.forename: Jose-Luis
authors.initials: JL
authors.lastname: Guinot
authors.affiliation: Department of Radiation Oncology, Inselspital, University of Bern, Switzerland.
authors.forename: Kristina
authors.initials: K
authors.lastname: Lössl
authors.affiliation: Department of Radiotherapy and Radiobiology, University Hospital Vienna, Austria.
authors.forename: Daniela
authors.initials: D
authors.lastname: Kauer-Dorner
authors.affiliation: Department of Radiotherapy and Radiobiology, University Hospital Vienna, Austria.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Resch
authors.affiliation: Interdisciplinary Brachytherapy Unit, University of Lübeck, Germany.
authors.forename: György
authors.initials: G
authors.lastname: Kovács
authors.affiliation: Department of Radiation Oncology, National Institute of Oncology, Budapest, Hungary.
authors.forename: Tibor
authors.initials: T
authors.lastname: Major
authors.affiliation: Department of Radiotherapy, University Hospital Gasthuisberg, Leuven, Belgium.
authors.forename: Erik
authors.initials: E
authors.lastname: Van Limbergen
mesh_terms: D001918:Brachytherapy / Q000379:methods; D001943:Breast Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D015588:Observer Variation; D047368:Tumor Burden
keywords: APBI; Boost; Brachytherapy; Breast cancer; Target definition