The investigators propose a prospective, randomized, pilot study, with active control, to evaluate the viability and safety of accelerated partial breast irradiation, in 5 fractions, comparing with the radiotherapy regimens of the whole breast in 15 and 5 fractions, in patients with breast cancer, in initial stage, who underwent conservative surgery.
Radiotherapy has been confirmed as an important treatment breast-conserving surgery reducing the risk of any recurrence of breast cancer and breast cancer-related mortality in patients with early breast cancer.~There are no comparative data on the ideal radiotherapy treatment regimen for patients with early stage breast cancer who underwent conservative surgery in the Brazilian population.