title: Clinical outcomes, toxicity, and cosmesis in breast cancer patients with close skin spacing treated with accelerated partial breast irradiation (APBI) using multi-lumen/catheter applicators.
abstract: OBJECTIVE
  Accelerated partial breast irradiation (APBI) using a single-lumen device is associated with better cosmetic outcomes if the spacing between the applicator and skin is > 7 mm. However, there are no reports addressing the late toxicity and clinical outcomes in patients treated with single-entry multi-lumen/catheter applicators who had close skin spacing (7 mm or less). We undertook this study to report clinical outcome, acute and late toxicity as well as cosmesis of early stage breast cancer patients with close skin spacing treated with APBI using multi-lumen or multi-catheter devices.
  
  
  METHODS
  This is a retrospective study of all breast cancer patients who had undergone APBI using single-entry multi-lumen/catheter devices in a single institution between 2008 to 2012. The study was limited to those with ≤ 7 mm spacing between the device and skin.
  
  
  RESULTS
  We identified 37 patients and 38 lesions with skin spacing of ≤ 7 mm. Seven lesions (18%) had spacing of ≤ 3 mm. Median follow-up was 47.5 months. There was one case of ipsilateral breast recurrence and one ipsilateral axillary recurrence. Based on RTOG criteria, 22 treated lesions experienced grade 1 and 9 lesions experienced grade 2 toxicity. Twenty-one lesions experienced late grade 1 toxicity. One patient had to undergo mastectomy due to mastitis. Twenty-four treated breasts showed excellent and 11 had good cosmetic outcome. Overall cosmesis trended towards a significant correlation with skin spacing. However, all patients with ≤ 3 mm skin spacing experienced acute and late toxicities.
  
  
  CONCLUSIONS
  Accelerated partial breast irradiation can be safely performed in patients with skin spacing of ≤ 7 mm using single-entry multi-lumen/catheter applicators with excellent cosmetic outcomes and an acceptable toxicity profile. However, skin spacing of ≤ 3 mm is associated with acute and late toxicity and should be avoided if possible.
authors.affiliation: Department of Radiation Oncology, University of Texas Medical Branch, Galveston, TX; Department of Radiation Oncology, Houston Methodist Hospital, Cancer Center and Research Institute, Houston, TX.
authors.forename: Mani
authors.initials: M
authors.lastname: Akhtari
authors.affiliation: Department of Radiation Oncology, Houston Methodist Hospital, Cancer Center and Research Institute, Houston, TX.
authors.forename: Mirna
authors.initials: M
authors.lastname: Abboud
authors.affiliation: Department of Radiation Oncology, University of Texas Medical Branch, Galveston, TX; Department of Radiation Oncology, Houston Methodist Hospital, Cancer Center and Research Institute, Houston, TX.
authors.forename: Sean
authors.initials: S
authors.lastname: Szeja
authors.affiliation: Department of Radiation Oncology, Houston Methodist Hospital, Cancer Center and Research Institute, Houston, TX.
authors.forename: Ramiro
authors.initials: R
authors.lastname: Pino
authors.affiliation: Department of Radiation Oncology, University of Texas Medical Branch, Galveston, TX; Department of Radiation Oncology, Houston Methodist Hospital, Cancer Center and Research Institute, Houston, TX.
authors.forename: Gary D
authors.initials: GD
authors.lastname: Lewis
authors.affiliation: Department of Surgery, Houston Methodist Hospital, Houston, TX.
authors.forename: Barbara L
authors.initials: BL
authors.lastname: Bass
authors.affiliation: Texas Women's Comprehensive Breast Center, USA.
authors.forename: Darlene M
authors.initials: DM
authors.lastname: Miltenburg
authors.affiliation: Department of Radiation Oncology, Houston Methodist Hospital, Cancer Center and Research Institute, Houston, TX.
authors.forename: E Brian
authors.initials: EB
authors.lastname: Butler
authors.affiliation: Department of Radiation Oncology, Houston Methodist Hospital, Cancer Center and Research Institute, Houston, TX.
authors.forename: Bin S
authors.initials: BS
authors.lastname: Teh
keywords: APBI; breast cancer; skin spacing