A single dose of irradiation to the lumpectomy cavity alone after breast-conserving surgery in breast cancer patients has been available in the Netherlands since 2011. This new treatment modality is used in the Haaglanden Medical Centre in The Hague and in the Catharina Hospital in Eindhoven. The goal of intraoperative radiation therapy is to limit the patient burden caused by whole breast irradiation, while maintaining excellent local tumour control. The technique is used only in patients with a low probability of recurrent disease in the breast. Approximately 150 patients receive intraoperative radiation therapy each year In the Netherlands, an estimated 4,000 breast cancer patients were eligible in 2013 for this new treatment technique or another method of partial breast irradiation. In both hospitals the results are closely monitored. Only 15 of the first 200 patients experienced a side effect within a period of 3 months after intraoperative radiation therapy. These side effects were successfully treated either with antibiotics or with surgery.