The RS-1400 spine-segment daily IGRT quality assurance phantom provides four thoracic vertebrae with six markers in a precision machined translucent block of tissue equivalent material. Machined centering lines are inscribed in the block phantom for reproducible set-up. Three graphite markers are provided for KV imaging and three gold markers are provided for MV imaging. After set-up, daily quality assurance measures reproducibility and accuracy of image derived re-location of treatment isocenter(s) to any of the imaged markers. As an option, the phantom can be machined to accommodate an ion chamber or other measurement device. The ART torso segment option includes ribs, soft tissue, organs, and lung for realistic imaging in cone-beam CT and planar imaging for use in daily QA as well as for IGRT therapist training.