Accelerated partial breast irradiation: History, rationale, and controversies

Accelerated partial breast irradiation (APBI) may prove to be an exciting advance in breast cancer treatment, in that APBI reduces the six-week traditional course of whole breast radiation to a one-week schedule. This schedule is more convenient for most patients and may allow for a breast-conserving approach for patients who are unable to come to a facility for the more protracted course of whole breast treatment. However, it is important to note that the benefits of whole breast treatment have been well defined through at least two decades of study. It is clear that this whole breast irradiation is highly effective at reducing the risk of breast recurrence, and importantly, by reducing this risk, improves overall survival. While it is possible that APBI may be able to achieve similar excellent outcomes in appropriately selected patients, to date, the popular APBI techniques such as balloon-based brachytherapy and external-beam radiation do not have five-year outcome data. Accordingly, there remains some uncertainty regarding the safety and efficacy of these techniques. Fortunately, a number of prospective randomized trials comparing APBI and whole breast radiation are meeting accrual goals and will be able to define the role of APBI in breast cancer management.