 A previous study of pilot imaging using this device without the 60Co sources was completed in 2012 HRPO 201105295. In this study, a total of 26 patients were imaged with the device. Fourteen of these patients also had onboard CT imaging OB-CT where the two sets of imaging and relative organs at risk OARs could be compared. Fifteen to 24 OARs were evaluated per anatomical site. In total, 221 OARs and 10 target structures were compared for visualization on MRI and OB-CT image sets by each physician. At least 23 physicians evaluated MRI as offering better visualization for 71 of structures, OB-CT offering better visualization for 10 of structures, and both offering equivalent visualization for 14 of structures. Physicians agreed unanimously for 74 and in majority for 99 of structures evaluated, respectively. For 1 of structures, no consensus was reached. Targets were better visualized on MRI in 410 cases, and were never better visualized on OB-CT images. 