[Radiotherapy in breast cancer: standards and new directions, accelerated partial breast irradiation]

Radiotherapy as a part of the breast cancer treatment has evolved in the last decades. Post-mastectomy radiotherapy produces a substantial reduction in the risk of local recurrence as well as a moderate, but definitive reduction in long-term breast cancer mortality in women at high risk of locoregional failure. Whole-breast irradiation, as part of breast-conservation therapy, has well-established results with good cosmesis, and low toxicity. Results from the BCT trials suggest that the risk for ipsilateral breast cancer recurrence resides within close proximity to the original tumor site. This has led investigators to consider the role of an accelerated and more tumor bed-focused course of radiotherapy. Accelerated partial-breast irradiation (APBI) is a collection of radiotherapy techniques that deliver higher daily doses of radiation to the surgical cavity with margin over a shorter time than whole breast irradiation (from 6-6.5 weeks to 1 week). Early results of this approach have demonstrated excellent local control, minimal acute toxicity, and are more convenient for the patient. Phase III randomized clinical trials are currently underway to assess local control, acute and chronic toxicities. APBI extend the choise of breast conservation.