A radiation treatment bra and method for its use are disclosed. In theillustrative embodiment, the bra includes adjustable elements and a medialwindow. During radiation treatment planning, the elements are adjusted toestablish a reference breast geometry. The reference breast geometry isreproduced prior to an actual treatment session by repeating the originaladjustment of the elements, as necessary. The medial window enables a lightfieldto be projected onto the patients chest, and read therefrom, therebyestablishingproper alignment of the patient to the radiation treatment machine.
