title: Extended (5-year) outcomes of accelerated partial breast irradiation using MammoSite balloon brachytherapy: patterns of failure, patient selection, and dosimetric correlates for late toxicity.
abstract: OBJECTIVE
  Accelerated partial breast irradiation (APBI) with balloon and catheter-based brachytherapy has gained increasing popularity in recent years and is the subject of ongoing phase III trials. Initial data suggest promising local control and cosmetic results in appropriately selected patients. Long-term data continue to evolve but are limited outside of the context of the American Society of Breast Surgeons Registry Trial.
  
  
  METHODS
  A retrospective review of 157 patients completing APBI after breast-conserving surgery and axillary staging via high-dose-rate (192)Ir brachytherapy from June 2002 to December 2007 was made. APBI was delivered with a single-lumen MammoSite balloon-based applicator to a median dose of 34 Gy in 10 fractions over a 5-day period. Tumor coverage and critical organ dosimetry were retrospectively collected on the basis of computed tomography completed for conformance and symmetry.
  
  
  RESULTS
  At a median follow-up time of 5.5 years (range, 0-10.0 years), the 5-year and 7-year actuarial incidences of ipsilateral breast control were 98%/98%, of nodal control 99%/98%, and of distant control 99%/99%, respectively. The crude rate of ipsilateral breast recurrence was 2.5% (n=4); of nodal failure, 1.9% (n=3); and of distant failure, 0.6% (n=1). The 5-year and 7-year actuarial overall survival rates were 89%/86%, with breast cancer-specific survival of 100%/99%, respectively. Good to excellent cosmetic outcomes were achieved in 93.4% of patients. Telangiectasia developed in 27% of patients, with 1-year, 3-year, and 5-year actuarial incidence of 7%/24%/33%; skin dose >100% significantly predicted for the development of telangiectasia (50% vs 14%, P<.0001).
  
  
  CONCLUSIONS
  Long-term single-institution outcomes suggest excellent tumor control, breast cosmesis, and minimal late toxicity. Skin toxicity is a function of skin dose, which may be ameliorated with dosimetric optimization afforded by newer multicatheter brachytherapy applicators and a more rigorous skin dose constraint of ≤100%.
authors.affiliation: University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania.
authors.forename: John A
authors.initials: JA
authors.lastname: Vargo
authors.affiliation: University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania.
authors.forename: Vivek
authors.initials: V
authors.lastname: Verma
authors.affiliation: University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania.
authors.forename: Hayeon
authors.initials: H
authors.lastname: Kim
authors.affiliation: University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania.
authors.forename: Ronny
authors.initials: R
authors.lastname: Kalash
authors.affiliation: University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania.
authors.forename: Dwight E
authors.initials: DE
authors.lastname: Heron
authors.affiliation: University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania.
authors.forename: Ronald
authors.initials: R
authors.lastname: Johnson
authors.affiliation: University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania. Electronic address: beriwals@upmc.edu.
authors.forename: Sushil
authors.initials: S
authors.lastname: Beriwal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D001943:Breast Neoplasms / Q000453:epidemiology / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007496:Iridium Radioisotopes / Q000627:therapeutic use; D015412:Mastectomy, Segmental; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000453:epidemiology; D018579:Patient Selection; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012867:Skin / Q000528:radiation effects; D015996:Survival Rate; D013684:Telangiectasis / Q000453:epidemiology / Q000209:etiology; D016896:Treatment Outcome
chemical_list: D007496:Iridium Radioisotopes