Prone Breast Radiotherapy Treatment Planning Observational Study

Retrospectively identify women who received curative radiation treatment after breast conserving cancer surgery, in whom simulation in prone and in supine position was performed. Compare the treatment plans for doses to targets and to non-target organs, according to clinical parameters of body mass index, size of breast, location of tumor and side. Furthermore, evaluate whether a single CT slide is enough or not to predict a dosimetry advantage.