A bra to accommodate and position a woman&rsquos breasts when receiving radiation treatment to ensure precise and reproducible radiation is delivered to a target area during each treatment session includes two breast cups (102A, 102B) a medial window (108) two shoulder straps (104A, 104B) and a back band. The medial window (108) is visually transparent and is disposed between the two breast cups (102A, 102B). The two shoulder straps (104A, 104B) support the two breast cups (102A, 102B). The back band couples the shoulder straps (104A, 104B) and the two breast cups (102A, 102B). The breast cups (102A, 102B), medial window (108), shoulder straps (104A, 104B) and back band, by virtue of the materials of construction, do not scatter or substantially attenuate treatment radiation. The bra is configured so that when worn, no portion of a vertical midline of a wearer&rsquos chest is obscured by the bra so that a light field can be projected through the medial window (108) onto a wearer&rsquos chest and viewed without obstruction.
