In one aspect, the present disclosure relates to a head fixation apparatus including a number of support posts, and a curved ring portion including a number of connectors configured to adjustably and releasably mount support posts on the lower ring portion, such that the support posts are selectively mounted to a subset of the connectors in a customized arrangement for a patient. The apparatus may include a ring mount configured for fixation to a platform, including a curved channel substantially matching a curvature of the curved ring portion, and a mount locking mechanism for locking the curved ring portion within the channel of the ring mount. The curved ring portion may be configured to rotate within the channel of the ring mount while the ring mount is fixed to the platform, an angular head position of the patient being selectably adjustable while the patient is laying on the platform.