Feasibility and impact of national peer reviewed clinical audits in radiotherapy departments.

•Clinical audits using the QUATRO methodology have been successfully carried out in all Belgian radiotherapy departments from 2011 to 2015.•National radiotherapy improvement initiatives should focus on quality of the facility and equipment, the development of organisational charts, and the improvement of incident and near-incident feedback.•Formal patient follow-up programs after radiotherapy delivery should be established.•Lack of training and professional development of RTTs was also pointed out as being an area needing to be improved.