title: Three-year analysis of treatment efficacy, cosmesis, and toxicity by the American Society of Breast Surgeons MammoSite Breast Brachytherapy Registry Trial in patients treated with accelerated partial breast irradiation (APBI).
abstract: BACKGROUND
  This report presents 3 years of data on treatment efficacy, cosmetic results, and toxicities for patients enrolled on the American Society of Breast Surgeons MammoSite (Cytyc, Bedford, Mass) Breast Brachytherapy Registry Trial.
  
  
  METHODS
  A total of 1440 patients (1449 cases) with early stage breast cancer who were undergoing breast-conserving therapy were treated with the MammoSite device to deliver accelerated partial breast irradiation (APBI) (34 Gy in 3.4 Gy fractions). Of these, 1255 (87%) cases had invasive breast cancer (IBC; median size = 10 mm), and 194 (13%) cases had ductal carcinoma in situ (DCIS; median size = 8 mm). Median follow-up was 30.1 months.
  
  
  RESULTS
  Twenty-three (1.6%) cases developed an ipsilateral breast tumor recurrence (IBTR) for a 2-year actuarial rate of 1.04% (1.11% for IBC and 0.59% for DCIS). No variables were associated with IBTR. Six (0.4%) patients developed an axillary failure. The percentages of breasts with good to excellent cosmetic results at 12 (n = 980), 24 (n = 752), 36 (n = 403), and 48 months (n = 67 cases) were 95%, 94%, 93%, and 93%, respectively. Breast seromas were reported in 23.9% of cases (30% in open-cavity implants and 19% in closed-cavity implants). Symptomatic seromas occurred in 10.6% of cases, and 1.5% of cases developed fat necrosis. A subset analysis of the first 400 consecutive cases enrolled was performed (352 with IBC, 48 DCIS). With a median follow-up of 37.5 months, the 3-year actuarial rate of IBTR was 1.79%.
  
  
  CONCLUSIONS
  Treatment efficacy, cosmesis, and toxicity 3 years after treatment with APBI using the MammoSite device are good and similar to those reported with other forms of APBI with similar follow-up.
authors.affiliation: Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan 48072, USA. fvicini@beaumont.edu
authors.forename: Frank
authors.initials: F
authors.lastname: Vicini
authors.forename: Peter D
authors.initials: PD
authors.lastname: Beitsch
authors.forename: Coral A
authors.initials: CA
authors.lastname: Quiet
authors.forename: Angela J
authors.initials: AJ
authors.lastname: Keleher
authors.forename: Delia
authors.initials: D
authors.lastname: Garcia
authors.forename: Howard C
authors.initials: HC
authors.lastname: Snider
authors.forename: Mark A
authors.initials: MA
authors.lastname: Gittleman
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Zannis
authors.forename: Henry M
authors.initials: HM
authors.lastname: Kuerer
authors.forename: Maureen
authors.initials: M
authors.lastname: Lyden
mesh_terms: D000328:Adult; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D001940:Breast / Q000473:pathology / Q000528:radiation effects*; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D004954:Esthetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011829:Radiation Dosage; D012042:Registries / Q000706:statistics & numerical data; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome