A method for quality assurance of dynamic wedge

Background: One of the important prerequisites for using a virtual wedge is the availability of an appropriate method for quality assurance. A simple method to determine wedge angles has been developed. Material and Methods: A formula based on the exponential attenuation curve has been derived, that allows for the calculation of the wedge isodose angl es based on 2 measurement points perpendicular to the central ray. The line ar attenuation coefficient is the only variable that must be known for the field size under consideration. Results: Using the algorithm introduced, the wedge angle isodoses can be me asured with a high degree of accuracy. The deviation of the wedge angle com pared to the measurements done according to DIN 6847-4 is less than 1 degre es. Conclusion: The described procedure is a simple method of performing routin e quality assurance for the virtual wedge.