Feasibility of breast preserving therapy with single fraction in situ radiotherapy delivered intraoperatively.

BACKGROUND: Accelerated partial breast irradiation (APBI) has gained widespread interest as a means of improving the convenience and availability of breast conserving radiotherapy. Intraoperative radiation therapy (IORT) is an APBI technique that delivers breast radiotherapy as a single dose at the time of partial mastectomy. We adapted the technique of Veronesi to deliver IORT prior to tumor excision to improve delivery to the region at risk and reduce the volume of normal tissue irradiated. METHODS: Patients age >or=55 with ultrasonographically defined tumors