Accelerated partial breast irradiation with intraoperative electrons: Using GEC-ESTRO recommendations as guidance for patient selection

Purpose: To evaluate outcomes among early-stage breast cancer patients after conservative surgery and full-dose intraoperative radiotherapy electrons (ELIOT) by applying the Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) recommendations for partial breast irradiation (APBI). Materials and Methods: One-thousand eight-hundred and twenty-two patients were stratified into the three GEC-ESTRO categories of "good candidates", "possible candidates" and "contraindication" in order to assess outcomes. Results: All the 1822 cases except 7 could be classified according to GEC-ESTRO groups: 573 patients met the criteria to be included in the "good candidates" group, 468 patients in the "possible candidates" group and 767 patients in the "contraindication" group. Median and mean follow-up length was 3.5 years (range 0-10.5 years) and 3.8 years (SD 2.2), respectively. The 5-year rate of in-breast tumor reappearances for "good candidates", "possible candidates" and "contraindication" groups were 1.9%, 7.4% and 7.7%, respectively (p 0.001). While the regional node relapse showed no difference, the rate of distant metastases was significantly different in the "contraindication" group compared to the other two categories, having a significant impact on survival. Conclusions: Among the ELIOT population, the GEC-ESTRO recommendations enabled the selection of the good candidates with a low rate of local recurrence, but failed to differentiate the "possible candidates" and the "contraindication" groups.