Feasibility Study of Accelerated Preoperative Radiotherapy for Early Breast Cancer

"Dose prescription:~Whole breast irradiation: 25 Gy in 5 daily fractions of 5 Gy Boost: 30 Gy in 5 daily fractions of 6 Gy The boost will be delivered as a simultaneous integrated boost (SIB).~Target volumes:~Clinical target volume (CTV) breast: defined by the soft tissue of the breast down to the pectoralis fascia, but excluding the skin and the underlying muscle, ribs, lung and heart.~Gross tumor volume (GTV) boost: includes all gross tumor volume, as visible on computer tomography, mammography and/or magnetic resonance imaging (MRI). MRI imaging is preferentially performed in treatment position.~CTV boost: includes the primary tumor, with a margin of 1.0 cm in all directions to encompass potential microscopic disease extension. The CTV boost excludes the skin, pectoralis muscle, ribs, lung and heart.~Planning target volume (PTV): CTV plus a margin of 5 mm in all directions, but limited at 5 mm below the skin surface."