Accelerated Partial Breast Irradiation: A Review and Description of an Early North American Surgical Experience With the Intrabeam Delivery System

Background: Targeted intraoperative radiation therapy (IORT) as an alternative to whole breast irradiation (WBI) has been described for patients with early-stage breast cancer. The randomized phase HI TARGiT trial demonstrated similar recurrence rates to WBI and a lower overall toxicity profile on short-term follow-up. We report on our early North American surgical experience using the Intrabeam radiotherapy delivery system and review the current literature. Methods: Prospectively gathered estrogen receptor-positive, clinically node-negative patients with invasive breast cancer <3 cm receiving IORT using the Intra beam system were reviewed. IORT-related effects and early postoperative outcome were assessed. A literature review was also performed. Results: Forty-two patients (median age 71 years) underwent lumpectomy, sentinel lymph node (SLN) biopsy, and concurrent IORT from January 2011 to July 2011. Ninety-one percent of patients had invasive ductal histology with a median tumor size of 1.0 cm. This review highlights the patient selection criteria, describes commercially available accelerated partial breast irradiation (APBI) treatment options, and discusses outcomes for the variety of APBI techniques currently utilized in clinical practice as well as an istitutional review of our early surgical experience using the Intra beam radiotherapy delivery system. Conclusions: While a variety of APBI techniques are currently available for clinical use, our early North American operative experience with IORT shows it is well tolerated with low morbidity. Delivery of IORT adds moderate operative time and may require creating subcutaneous tissue flaps. The addition of WBI may be necessary in situations for positive residual margins or microscopic nodal disease in patients who do not undergo additional surgery.