Breast conserving surgery with targeted intraoperative radiotherapy for the management of ductal carcinoma in situ.

Background: A prospective randomized controlled trial has established the efficacy of targeted intraoperative radiotherapy (TARGIT) in the management of invasive breast cancer treated with breast-conserving surgery (BCS). The purpose of this analysis is to evaluate the efficacy of TARGIT in the management of ductal carcinoma in situ (DCIS).

Methods: A prospective nonrandomized trial was designed to evaluate the success of TARGIT in the management of DCIS, as measured by a low risk of requiring additional surgery or radiotherapy and an acceptable local recurrence rate (LRR).

Results: Fifty-five patients with DCIS received BCS and TARGIT from November 2007 to March 2017. Median patient age was 57 years (range, 42-83 years) and median histological lesion size was 14.4 mm (range, 2-51 mm). Four patients required either re-excision and/or whole breast irradiation, yielding a rate of additional therapy of 7.3% (4 of 55). Among 46 women administered TARGIT at the time of initial BCS, two local recurrences were observed yielding a 4.3% (2 of 46) LRR at 46 months median follow-up (range, 4-116 months). There were no clinically significant adverse events.

Conclusions: Preliminary evidence indicates TARGIT can be performed with a low risk of requiring additional therapy (7.3%) and an acceptable LRR (4.3%) when administered at the time of BCS.