PURPOSE:Morbidity and mortality review (MMR) meetings in radiation therapy (RT) departments aim to monitor radiation-induced toxicities and identify potential factors that may be correlated with their development and severity, particularly treatment planning errors. The aims of the Prospective Registration of Morbidity and Mortality, Individual Radiosensitivity and Radiation Technique (PROUST) survey were to make an inventory of existing MMR procedures and to describe their procedures.METHODS AND MATERIALS:The link to the web-based questionnaire of the PROUST survey was sent to 351 radiation oncologists working at 172 centers. The questionnaire included items related to organization, frequency, membership, governance, reasons for nonimplementation of MMR, and interest in its creation.RESULTS:As of July 2017, 108 responses had been received from the 172 centers, of which 107 responses were completed for analysis. All centers declared that they had initiated a quality assurance program in their department, including implementation of feedback committees dedicated to the registration, analysis, and correction of precursor events. Less than half of the centers (47%) had implemented MMR procedures. However, there was significant confusion regarding feedback committees in a majority of the centers. MMRs were organized every 6 and 12 months in 21% and 15%, respectively, of the centers. In 60% of the centers, toxicity grade ≥3 was the main reason for the MMR initiation. In routine practice, contouring and dosimetry files were reviewed by 66% and 83%, respectively, of centers practicing MMR. However, only 40% of the centers enrolled data in a registry dedicated to surveillance. Finally, 78% of centers expressed interest in initiating a consensual procedure.CONCLUSIONS:MMRs are not systematically implemented in RT departments worldwide. In France and in Europe, few departments with quality assurance programs have implemented MMRs. This survey showed that a large majority of centers are interested in implementing an MMR with a formalized procedure. Our project could help increase the interest of the RT community worldwide in this topic.