A radiation dosimetry quality assurance system is disclosed that includes a three-dimensional (3D) phantom extending along a longitudinal axis to form an exterior surface and an interior volume and a passage formed to extend into the interior volume of the 3D phantom to removeably receive a detector array therein. The system also includes an angular-compensation system coupled to the exterior surface of the 3D phantom and having a physical contour extending from the exterior surface of the 3D phantom and configured to control an angular dependence of the detector array during measurement of the actual radiation dose delivered by the radiation delivery system. The system further includes a detector-angle adjustment system configured to allow selection of a relative position of the detector array with respect to a radiation source of the radiation delivery system during measurement of the actual radiation dose delivered during the planned medical process.