Abstract: A pin closure system, especially for use in securing the upper and lower frame plates of a radiation therapy treatment mask. An upper sleeve having an expansile portion is placed and engaged within a shaped fenestration of an upper frame plate, while a lower sleeve having an expansile portion is placed and engaged within a shaped fenestration of a lower frame plate. An axial pin is inserted spanning both sleeves, causing the expansile portions to expand radially, engaging the sleeves together and locking the plates together. The system may also be used to use a single pin to simultaneously lock the upper and lower frame plates together and to an external substrate, such as a treatment table for repeatable and highly accurate patient positioning.

Abstract: An immobilization system, especially for use on the human head and neck area, is described in various embodiments. The system may include a bite block immobilization system having a bite block with a dental interface releasably engageable with a plurality of teeth of a patient, and a retention mask. The dental interface releasably engages the teeth of a patient and allows very highly accurate repositioning during multiple procedures. In some embodiments, the bite block may have an integral bite block airway passage, allowing a patient to have unobstructed breathing both during molding of the retention mask and during subsequent use of the system, and may include a tongue diverter, that may, by way of example only and not to limitation, be used to divert the tongue away from a therapeutic radiation beam. Steps for utilizing the system are further described.