Quality Research in Radiation Oncology (Q-RRO) seeks to assess the quality of care for radiation oncology patients. This unique quality initiative has had a major positive impact on current practice and has kept pace with dramatic alterations in the radiation oncology structural base and clinical processes. Results have assertively influenced continuing workup and treatment in radiation oncology and have been integral to progressive development of the highest standard of radiation oncology care in the world. In recent years technological capabilities for delivering both external beam radiotherapy and high- as well as low-dose rate brachytherapy have advanced rapidly and have entered the national practice. Detailed evaluation of the use of these technologies by all types of practice is crucial to continuing improvement in patient care. Q-RRO will define a core set of quality indicators for selected cancers, associated with high incidences and mortality, and will conduct a statistically well-designed set of surveys to collect data on those measures. For the nation and by practice setting, treatment technology, patient and disease factors, it will document compliance with quality indicators, as well as evaluate the penetration of results of recent positive clinical trials and of peer-reviewed, evidence-based, practice standards and guidelines. Particular emphasis will be placed on the process and quality of care for important emerging advanced technologies, such as seed implant treatment for prostate cancer, 3D Conformal Radiation Therapy (3DCRT) and Intensity Modulated Radiation Therapy (IMRT) for prostate, lung, gastric, and breast cancer, and High Dose rate (HDR) brachytherapy for cervical and breast cancer, based on the best available evidence. Detailed central evaluation of the use of prostate brachytherapy is enabled by a unique electronic image transfer system developed by the American College of Radiology Imaging Network (ACRIN), which is available to Q-RRO. A continuing important collaboration between the American College of Radiology and the American College of Surgeons will evaluate total care for rectal cancer patients. Ongoing close collaboration with other professional organizations will help expand education and communications programs to disseminate Q-RRO findings for multiple audiences, including radiation oncologists and other oncology professionals, patients and the public. The research team, highly experienced with a history of successful studies, stands as a role model yet to be fully emulated by any other medical discipline in the United States.