In an illustrative embodiment, an adjustable cradle assembly for adjusting a head position of a patient relative to a patient platform includes a base portion with a pair of vertical support members and a cradle portion. The vertical support members may each include at least one position aperture for setting a vertical height of the cradle portion relative to the base portion. The cradle portion may include a channel for receiving a head fixation ring. The cradle portion may include at least one set of adjustment connection points for aligning with position apertures of each vertical support member. The cradle may be pivotably connected to the vertical support members such that a pitch angle of a head position of a patient secured in the head fixation apparatus may be adjusted. A set of adjustment mechanisms may releasably secure the cradle to the base at a selected lateral and/or pitch position.