A patient positioning assembly for therapeutic radiation treatment includes a support device for supporting the patient during treatment, and a controller for controlling the motion of the support device so that the treatment target within the patient is properly aligned with respect to a radiosurgical treatment apparatus throughout the treatment. The controller generates motion command signals for implementing corrective motions of the support device. The corrective motions align the target so that the position and orientation of the target, as shown in near real time image data, substantially match the position and orientation of the target, as shown in pre-treatment scans. One or more user interface modules, for example a handheld remote control module and a user interface screen, allows the user to interactively control the motion of the support device, by implementing one or more user selectable functions.