title: Intraoperative Electron Radiotherapy (IOERT) as an Alternative to Standard Whole Breast Irradiation: Only for Low-Risk Subgroups?
abstract: BACKGROUND
  Intraoperative radiotherapy during breast-conserving surgery is being studied as an alternative to 6 weeks of external beam radiotherapy (EBRT) for low-risk women; it can be delivered using electrons (intraoperative electron radiotherapy, IOERT) or 50-kV X-rays.
  
  
  METHODS
  We analyzed both single institutional and randomized studies involving single-fraction IOERT treatments. Rates for ipsilateral breast tumor recurrences, disease-specific survival, and overall survival were obtained.
  
  
  RESULTS
  IOERT had true 5-year recurrence rates of > 1.5% for ASTRO (American Society for Radiation Oncology) and ESTRO (European Society for Therapeutic Radiology and Oncology) suitable women, or for low-risk women as defined by the ELIOT trial. Women with ductal carcinoma in situ eligible for breast-conserving therapy, older women that currently receive no EBRT, and younger women with favorable biology are additional potential candidates.
  
  
  CONCLUSIONS
  ASTRO suitable and ESTRO good women for accelerated partial breast irradiation are low-risk groups. Higher-risk women with favorable biology might also be suitable candidates for IOERT, providing the tumor biology can be determined prior to surgery. For intraoperative radiotherapy using 50-kV X-rays, follow-up was too short to assess the effectiveness of the treatment.
authors.affiliation: Dept. of Radiotherapy, University Hospital, Verona, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Maluta
authors.affiliation: Dept. of Radiotherapy, University Hospital, Verona, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Dall'Oglio
authors.affiliation: Intraop Medical Corporation, Sunnyvale, CA, USA.
authors.forename: Donald A
authors.initials: DA
authors.lastname: Goer
authors.affiliation: Dept. of Radiotherapy, Azienda Ospedaliera, Verona, Italy.
authors.forename: Nadia
authors.initials: N
authors.lastname: Marciai
keywords: Academic Review; Breast cancer; Radiotherapy