Clinical and technical characteristics of intraoperative radiotherapy (IORT) treatments: analysis from the ISIORT-EUROPE data registry.

Background. A joint analysis of clinical data from centres within the European section of the International Society of Intraoperative Radiation Therapy (ISIORT-Europe) was undertaken in order to define the range of intraoperative radiotherapy (IORT) techniques and indications encompassed by its member institutions. Materials and methods. In 2007, the ISIORTEurope centres were invited to record demographic, clinical and technical data relating to their IORT procedures in a joint online database. Retrospective data entry was possible. Results. The survey encompassed 21 centres and data from 3754 IORT procedures performed between 1992 and 2011. The average annual number of patients treated per institution was 42, with three centres treating more than 100 patients per year. The most frequent tumour was breast cancer with 2395 cases (63.8%), followed by rectal cancer (598 cases, 15.9%), sarcoma (221 cases, 5.9%), prostate cancer (108 cases, 2.9%) and pancreatic cancer (80 cases, 2.1%). Clinical details and IORT technical data from these five tumour types are reported. Conclusion. This is the first report on a large cohort of patients treated with IORT in Europe. It gives a picture of patient selection methods and treatment modalities, with emphasis on the main tumour types that are typically treated by this technique and may benefit from it.