Preoperative Magnetic Resonance Imaging to Obtain Adequate Resection Margins in Breast Conserving Surgery, (PRIMAR) Trial

The goal of this randomised study is to investigate if a supplementary preoperative breast Magnetic Resonance Imaging (MRI) improves the assessment of breast cancer and can help surgical planning such that sufficient resection margins can be obtained during breast conserving surgery. The main questions are: 1. Is preoperative breast MRI in addition to the currently used standard imaging methods ultrasound and mammography more accurate to detect Ductal Carcinoma in Situ and the invasive breast tumor compared to standard methods only? 2. Does preoperative breast MRI reduce the number of involved histological margins after breast conserving surgery in the MRI-group versus the control group?