Overview of accelerated partial breast irradiation.

Breast conserving therapy (BCT) has become an accepted option in the management of patients with early-stage breast cancer. However, studies have suggested that a lengthy course of adjuvant whole breast irradiation, as a component of BCT, may not always be necessary and that radiation therapy delivered only to the region of the tumor bed may be acceptable in appropriately selected patients. Several modalities are currently being explored as a means to deliver accelerated partial breast irradiation (APBI), including multicatheter interstitial brachytherapy, the MammoSite breast brachytherapy catheter (Cytyc Corporation, Marlborough, MA), and three-dimensional conformal external-beam radiation therapy. To date, phase 1/2 published data have demonstrated excellent local control rates and cosmesis. As additional data addressing the effectiveness of this treatment approach accumulate, a new standard of care may emerge. This review discusses data accumulated to date exploring the experience with all APBI modalities and presents future studies exploring this concept.