This study compares two different field set-ups in patients with breast cancer following a
breast resection (mastectomy). These two set-ups are as follows: arm a - radiotherapy to the
chest-wall only, and arm b - radiotherapy to the chest-wall and the supraclavicular fossa.
Patients in both treatment arms will receive radiotherapy with a shortened fractionation
Study hypothesis: irradiation of the chest-wall only is not inferior to irradiation of the
chest-wall and supraclavicular fossa in terms of loco-regional control, survival and