title: How do the ASTRO consensus statement guidelines for the application of accelerated partial breast irradiation fit intraoperative radiotherapy? A retrospective analysis of patients treated at the European Institute of Oncology.
abstract: OBJECTIVE
  To verify how the classification according to the American Society for Therapeutic Radiation Oncology (ASTRO) consensus statement (CS) for the application of accelerated partial breast irradiation (APBI) fits patients treated with intraoperative radiotherapy with electrons (ELIOT) at a single institution.
  
  
  METHODS
  The study included 1,822 patients treated with ELIOT as the sole radiation modality outside of a clinical trial at the European Institute of Oncology after breast-conserving surgery for invasive breast cancer, who were classified into CS groups of suitable, cautionary, and unsuitable. The outcome in terms of ipsilateral breast recurrence, regional node relapse, distant metastases, progression free-survival, cause-specific survival, and overall survival were assessed.
  
  
  RESULTS
  All the 1,822 cases except for 25 could be classified according to ASTRO CS: 294 patients met the criteria for inclusion into the suitable group, 691 patients into the cautionary group, and 812 patients into the unsuitable group. The 5-year rate of ipsilateral breast recurrence for suitable, cautionary, and unsuitable groups were 1.5%, 4.4%, and 8.8%, respectively (p = 0.0003). Whereas the regional node relapse showed no difference, the rate of distant metastases was significantly different in the unsuitable group compared with the suitable and cautionary groups, having a significant impact on survival.
  
  
  CONCLUSIONS
  In the context of patients treated with ELIOT, the ASTRO guidelines identify well the groups for whom APBI might be considered as an effective alternative to whole breast radiotherapy and also identify groups for whom APBI is not indicated.
authors.affiliation: Division of Radiation Oncology, European Institute of Oncology, Milan, Italy. cristina.leonardi@ieo.it
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Leonardi
authors.forename: Patrick
authors.initials: P
authors.lastname: Maisonneuve
authors.forename: Mauro Giuseppe
authors.initials: MG
authors.lastname: Mastropasqua
authors.forename: Anna
authors.initials: A
authors.lastname: Morra
authors.forename: Roberta
authors.initials: R
authors.lastname: Lazzari
authors.forename: Nicole
authors.initials: N
authors.lastname: Rotmensz
authors.forename: Claudia
authors.initials: C
authors.lastname: Sangalli
authors.forename: Alberto
authors.initials: A
authors.lastname: Luini
authors.forename: Umberto
authors.initials: U
authors.lastname: Veronesi
authors.forename: Roberto
authors.initials: R
authors.lastname: Orecchia
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008875:Middle Aged; D001943:Breast Neoplasms / Q000453:epidemiology / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D002173:Cancer Care Facilities; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000453:epidemiology / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D032921:Consensus; D016208:Databases, Factual; D018572:Disease-Free Survival; D004583:Electrons / Q000627:therapeutic use; D005060:Europe; D007430:Intraoperative Care / Q000592:standards; D015412:Mastectomy, Segmental; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000401:mortality; D017410:Practice Guidelines as Topic; D018787:Radiation Oncology / Q000592:standards; D012189:Retrospective Studies; D012955:Societies, Medical / Q000592:standards; D047368:Tumor Burden; D014481:United States; D003245:Consensus Statements as Topic