Single dose IOERT versus whole breast irradiation : Cosmetic results in breast-conserving therapy

Background: Scarce data are available about the cosmetic result of single dose intraoperative electron radiotherapy (IOERT) in breast-conserving radiotherapy.

Methods and materials: We included 71 breast cancer patients. Breast-conserving surgery and sentinel node procedure had started almost 3 years earlier. Subsequently, 26 patients were treated with IOERT and 45 patients received postoperative whole breast irradiation (WBI). For both groups we determined seven dimensionless asymmetry features. We compared the subjectively and the objectively derived cosmetic scores with each other.

Results: For four asymmetry features we noted significantly smaller differences for patients treated with IOERT when compared to those treated with WBI: relative breast contour difference, relative breast area difference and relative breast overlap difference. After correcting for excision volume a significant difference was noticed also for relative lower breast contour. For the IOERT group the cosmetic scores "excellent or good" as determined by each patient and one physician were 88 and 96 %, respectively. When the overall cosmetic scores for patients treated with IOERT and WBI were compared to those of the objectively derived scores, there was a fair level of agreement.

Conclusion: For patients treated with IOERT we noted less asymmetry and high rates of "good or excellent" subjectively derived cosmetic scores. The level of agreement between the subjectively and the objectively derived cosmetic scores was limited. Due to the small sample size and the design of the study no definitive conclusions can be drawn.