title: Six-year analysis of treatment-related toxicities in patients treated with accelerated partial breast irradiation on the American Society of Breast Surgeons MammoSite Breast Brachytherapy registry trial.
abstract: BACKGROUND
  The American Society of Breast Surgeons (ASBrS) enrolled women in a registry trial to prospectively study patients treated with the MammoSite RTS device. This report presents 6-year data on treatment-related toxicities from the trial.
  
  
  METHODS
  A total of 1449 primary early-stage breast cancers were treated with accelerated partial breast irradiation (APBI) using the MammoSite device (34 Gy in 10 fractions) in 1440 women. Of these, 1255 case (87%) had invasive breast cancer (IBC) (median size = 10 mm) and 194 cases (13%) had ductal carcinoma in situ (DCIS) (median size = 8 mm). Median follow-up was 59 months. Fisher exact test was performed to correlate categorical covariates with toxicity.
  
  
  RESULTS
  Breast seromas were reported in 28% of cases (35.5% with open cavity and 21.7% with closed cavity placement). Also, 13% of all treated breasts developed symptomatic seromas, and 77% of these seromas developed during the 1st year after treatment. There were 172 cases (11.9%) that required drainage to correct. Use of chemotherapy and balloon fill >50 cc were associated with the development of symptomatic seromas. Also, 2.3% of patients developed fat necrosis (FN). The incidence of FN during years 1 and 2 were 0.9% and 0.8%, respectively. Seroma formation, use of hormonal therapy, breast infection, and A/B cup size were associated with fat necrosis. There were 138 infections (9.5%) recorded; 98% occurred during the 1st year after treatment. Chemotherapy and seroma formation were associated with the development of infections.
  
  
  CONCLUSIONS
  Treatment-related toxicities 6 years after treatment with APBI using the MammoSite device are similar to those reported with other forms of APBI with similar follow-up.
authors: Department of Radiation Oncology, Cancer Institute of New Jersey, New Brunswick, NJ, USA. atif.khan@rwjuh.edu
authors: A J
authors: AJ
authors: Khan
authors: Douglas
authors: D
authors: Arthur
authors: F
authors: F
authors: Vicini
authors: P
authors: P
authors: Beitsch
authors: H
authors: H
authors: Kuerer
authors: S
authors: S
authors: Goyal
authors: Maureen
authors: M
authors: Lyden
authors: B G
authors: BG
authors: Haffty
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D001940:Breast / Q000528:radiation effects*; D001943:Breast Neoplasms / Q000532:radiotherapy*; D005218:Fat Necrosis / Q000209:etiology; D005260:Female; D005348:Fibrocystic Breast Disease / Q000209:etiology; D005500:Follow-Up Studies; D006801:Humans; D008413:Mastitis / Q000209:etiology; D059373:Mastodynia / Q000209:etiology; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology* / Q000628:therapy*; D012042:Registries; D012253:Rib Fractures / Q000209:etiology; D049291:Seroma / Q000209:etiology; D016896:Treatment Outcome