Pre- Versus Postoperative Accelerated Partial Breast Irradiation

Most of the local recurrences (LR) found after breast-conserving therapy are within or close to the tumor bed. This pattern of recurrence was confirmed by studies of breast conserving surgery without adjuvant irradiation and by the update of the NSABP B-06 trial. In the EORTC boost trial, however, 29% of all LR were found outside the area of the original tumor. Still, a recent review of Breast Conserving Therapy (BCT) trials showed that the site of local recurrences after BCT was mostly in the tumor bed, with less than 10% of LR elsewhere in the breast. This led to the concept of partial breast irradiation. With accelerated partial breast irradiation (APBI), a limited volume of breast tissue is irradiated, allowing for a higher dose per fraction compared to whole breast irradiation (WBI), which is favorable considering the low alpha/beta ratio, and thus higher sensitivity to high dose per fraction.

Patients will undergo a partial accelerated breast irradiation pre-or postoperative of 5 x 5.2 Gy