Guidance is provided for Radiation Protection Advisers (RPAs) involved in the design of x-ray facilities and for RPAs, medical physicists and others involved in the acceptance/commissioning testing or routine performance evaluation of dental cone beam CT equipment. Current guidance for conventional x-ray equipment in these areas is not appropriate, and this report details the recommendations of the Health Protection Agency Working Party established to develop guidance on all aspects of radiation safety matters related to dental cone beam CT equipment.
An achievable dose of 250 mGy cm2 is proposed as a starting point for the optimisation of patient dose, although it is recognised that the large differences between equipment models require that local diagnostic reference levels should be set after consultation between the user and their Medical Physics Expert (MPE).
It is recommended that new equipment should be purchased that is capable of restricting doses to below the achievable dose, as well as provided with the means to carry out the appropriate quality assurance checks proposed in this report. Employers are strongly encouraged to seek the advice of their MPE prior to purchasing a cone beam CT machine, to ensure the selected equipment best meets their requirements and is capable of restricting patient doses as far as reasonably practicable.