Frederik Wenz，University Medical Center Mannheim, University of Heidelberg, Germany
Frank A. Giordano，University Medical Center Mannheim, University of Heidelberg, Germany
Pedro Lara, University of Las Palmas, Canary Islands, Spain
The application of intraoperative radiotherapy (IORT) resembles the most effective approach to spare healthy tissue and at the same time to deliver extraordinarily high single doses of radiotherapy to (microscopically or macroscopically) remaining tumor cells. Beside the most widely known application in early-stage breast cancer, where IORT turned out to be non-inferior to postoperative external beam radiation therapy in two large phase III trials, IORT is to date increasingly used by multiple disciplines to treat a broad variety of tumors, including sarcoma, high-grade gliomas, brain and spinal metastases, head-and neck carcinomas or cervical cancer. In this focused issue, IORT experts give insights on their views and researchers publish novel developments in this moving field.