The ATC® serves the NCI National Clinical Trial Network (NCTN) as a component of the Imaging and Radiation Oncology Core (IROC) group. The goals of IROC are to (1) establish an integrated group to provide expertise, quality assurance and data management to the NCTN and NCI supported clinical trials in collaborative, coordinated and timely manner; (2) develop and implement a uniform and efficient radiotherapy quality assurance and credentialing program for NCI supported clinical trials; (3) develop and implement a uniform and efficient imaging quality assurance and credentialing program for NCI supported clinical trials; (4) develop an information technology infrastructure that harmonizes IROC services, data collection, assessment and management for NCI supported clinical trials; (5) establish and maintain a collaborative and inclusive communications program across the IROC Services Group QA centers and between IROC and the NCTN groups; and (6) conduct and support innovative research focused on NCI supported clinical trials, IROC QA processes and imaging data collection, and assessment.