title: Intraoperative radiation therapy: a critical analysis of the ELIOT and TARGIT trials. Part 1--ELIOT.
abstract: BACKGROUND
  Two randomized intraoperative radiation therapy trials for early-stage breast cancer were recently published. The ELIOT Trial used electrons (IOERT), and the TARGIT-A Trial Update used 50-kV X-rays (IORT). These studies were compared for similarities and differences. The results were analyzed and used to determine which patients might be suitable for single-dose treatment.
  
  
  METHODS
  The primary sources of data were the ELIOT Trial and TARGIT-A Trial, as well as a comprehensive analysis of the peer-reviewed literature of accelerated partial breast irradiation (APBI) using 50-kV X-rays or electrons. Studies published or presented prior to March 2014 were analyzed for efficacy, patient restrictions, complications, and outcome.
  
  
  RESULTS
  With a median follow-up of 5.8 years, the 5-year recurrence rates for ELIOT versus external beam radiation therapy (EBRT) patients were 4.4 % and 0.4 %, respectively, p = .0001. A low-risk ELIOT group was identified with a 5-year recurrence rate of 1.5 %. With a median follow-up of 29 months, the 5-year recurrence rates for the TARGIT-A versus EBRT patients were 3.3 % and 1.3 %, respectively, p = .042.
  
  
  CONCLUSIONS
  With 5.8 years of median follow-up, IOERT appears to have a subset of low-risk women for whom IOERT is acceptable. With 29 months of median follow-up the results of IORT with 50-kV devices are promising, but longer follow-up data are required. At the current time, single-fraction IOERT or IORT patients should be treated under strict institutional protocols.
authors.affiliation: Breast Center, Hoag Memorial Hospital Presbyterian, Newport Beach, CA, USA, melsilver9@gmail.com.
authors.forename: Melvin J
authors.initials: MJ
authors.lastname: Silverstein
authors.forename: Gerd
authors.initials: G
authors.lastname: Fastner
authors.forename: Sergio
authors.initials: S
authors.lastname: Maluta
authors.forename: Roland
authors.initials: R
authors.lastname: Reitsamer
authors.forename: Donald A
authors.initials: DA
authors.lastname: Goer
authors.forename: Frank
authors.initials: F
authors.lastname: Vicini
authors.forename: David
authors.initials: D
authors.lastname: Wazer
mesh_terms: D001943:Breast Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D003131:Combined Modality Therapy; D004583:Electrons / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007430:Intraoperative Care; D008408:Mastectomy; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D009367:Neoplasm Staging; D011379:Prognosis; D011879:Radiotherapy Dosage; D015996:Survival Rate; D014965:X-Rays