As long as breast cancer remains a pervasive health concern, the need for ever-improving breast cancer imaging and radiation therapy technologies will exist. Design changes – to incorporate new hardware technologies or methods - may trigger the need for clinical trials to ensure safety and assess performance. Conducting a clinical trial is not only expensive, but often takes years for patient recruitment and study. Utilizing physical phantoms, rather than patients, would be faster, far less expensive, reduces risk to patients and potentially increases the speed with which life-saving technological advances are made available to the public. Currently, commercially available compressed and uncompressed breast phantoms do not produce realistic breast images; rather they provide basic breast shapes with no anatomical information. Utilizing access to a large data set (over 200) of three-dimensional real patient breast CT images at UC Davis, and a novel approach to phantom development, we propose to fill this need. In this Phase II SBIR project, we will develop, and commercialize, patient-derived anthropomorphic phantoms for use in diagnostic and radiation therapy applications. We will also investigate the utility of our core technology in developing anthropomorphic phantoms for prostate, brain, and lung imaging applications.