Radiotherapy is a major treatment option in the management of many types of cancer. All UK incidents are voluntarily uploaded to the system, using standard classifications and coding for central analysis; feedback to the radiotherapy community and wider public is disseminated on a regular basis. Reporting for incidents involving patients has focused on over-exposures. Regular review and audit should be undertaken to ensure that practice is optimised and to reduce any potential risk of adverse incidents. Incident learning systems have been established internationally in many countries, but much more work is required to further push the safety envelope for the benefit of our patients worldwide, especially those in developing countries. The new legislation and the guidance on Much greater than intended has important consequences for monitoring and reporting doses involved for on-treatment verification imaging. In terms of on-treatment verification imaging, focus is made on the incorrect or nonuse of such verification methods.