Is Shorter Better? Hypofractionation Radiation Schemes in Breast Cancer

Postoperative radiation therapy is an integral component of breast-conserving treatment for patients with early-stage breast cancer and generally is administered using a conventional schedule of 50 Gy in 25 fractions with a boost dose to the tumor bed. This “standard” postoperative radiation therapy protocol substantially lowers risk for local recurrence — the Oxford Overview analysis of randomized radiation-therapy trials suggests that, for every four local recurrences that are avoided, one patient will be saved from death caused by breast cancer (Lancet 2005; 366:2087).

Although the standard radiation schedule evolved pragmatically, the underlying biological rationale is that small fraction sizes (i.e., ≤2 Gy) minimize normal tissue damage…