Hypo-fractionation (several large fractions as the only radiation treatment) for breast cancer irradiation was common in the forties and 50s and, while very successful in achieving tumor control, was found to leave significantly inferior cosmetic results due to severe fibrosis and telangiectasia compared to those obtained with multiple fraction regimens (38-40). These complications were due to the use of very large fields, with the inclusion of a large proportion of uninvolved skin and tissue surrounding the tumor.
Based on these assumptions, a few large fractions can be safely delivered to breast cancers provided that 1) the target volume is sufficiently small and 2) the radiation technique assures maximum sparing of the surrounding normal tissue. Conformal RT to the tumor bed of T1 breast cancers satisfies both requirements.
