Update of single institution experiences with intraoperative radiotherapy (IORT) in targeted oncoplastic breast surgery

Background: Breast-conserving surgery (BCS) is performed in an oncoplastic approach with tumor-specific immediate reconstruction of the partial mastectomy defect. In the attempt to further improve local outcome in breast-conserving therapy we introduced intraoperative radiotherapy (IORT) with low-kilovoltage X-rays as a boost during oncoplastic BCS followed by EBRT

Material and Methods: Between February 2010 and July 2012, a total of 149 patients were treated with IORT as a boost during primary oncoplastic breast-conserving surgery, followed by whole-breast radiotherapy. After segmental resection of the tumour during oncoplastic BCS the adequate applicator size for IORT-boost was evaluated. Resection defects were definitely reconstructed after IORT-boost using the predefined oncoplastic principles to achieve optimal esthetic results after BCS.

Results: Median age was 58 (range 36 – 86) years. There were T1 and T2 tumours in 117 and 29 patients, respectively, and N0, N1 and N2 disease in 111, 26, and 12 patients, respectively. The used radiation applicator-sizes ranged between 25 and 40 mm in 79% of the patients. The mean radiation time was 21 minutes. IORT boost radiotherapy was combined with oncoplastic principles for partial mastectomy reconstruction: glandular rotation (n = 109), dermoglandular rotation (n = 29), tumoradapted reduction mammoplasty

(n = 11). With a median follow-up of 7.6 months 1 patient had a chronic skin toxicity with percutaneous fistula, while 2 patients developed liponecrosis and 7 patients a seroma which was punctured.

Conclusion: The method supports the close interdisciplinarity between radiation therapy and breast surgery and can be combined with oncoplastic principles in breast-conserving surgery.