Comparison of Mastectomy Expander Trial

Expanders are used outside their intended use, due to two following facts: It is possible that expander implantation exceed the "approved" duration of 6 months (maximal 10 months). Additionally, some participants will receive after mastectomy/expander implantation an adjuvant radiotherapy according to standard of care, which is either a contraindication of the medical device or not yet tested in-vivo by the manufacturer. Requested answers: * how good is the aesthetic outcome of the breast with the expanders and the final implants, and whether any complications occurred during treatment, * how satisfied are subjects and doctors with the outcome of the breast reconstruction, and how the reconstruction affects health-related quality of life from participants, * how does the structural composition of the removed expanders looks like, in order to understand whether radiation therapy has caused changes in the material, * which key immunological factors lead to increased hardening of the tissue around the expander, especially during radiation therapy (capsule formation).