The National Council on Radiation Protection and Measurements (NCRP) recently assessed patient radiation exposure in the United States, which was summarized in its 2019 NCRP Report No. 184. This work involved an estimation of the number of medical procedures using ionizing radiation, as well as the associated effective doses from these procedures. The NCRP Report No. 184 committee elected to not incorporate radiation dose from radiotherapy into its calculated population dose exposures, as the assessment of effective dose for the population undergoing radiotherapy is more complex than that for other medical radiation exposures. However, the aim of NCRP Report No. 184 was to raise awareness of ancillary radiation exposures to patients undergoing radiotherapy. Overall, it was estimated that annually, in 2016, approximately 800,000 patients received approximately 1 million courses of radiation therapy. Each of these treatments includes various types of imaging that may not be familiar to radiologists or others. Exposures from radiotherapy planning and delivery are reviewed in the report and summarized in this executive summary. The imaging techniques, use of this imaging, and associated tissue doses are described. Imaging can contribute a few percent to the planned treatment doses (which are prescribed to specified target volumes) as well as exposing patients to radiation outside of the target volume (in the imaging field of view).

The Nationwide Evaluation of X-Ray Trends (NEXT) program is a long-running collaboration by the FDA with the Conference of Radiation Control Program Directors (CRCPD) to document the state of radiologic practice through periodic surveys of the clinical imaging community. An x-ray modality or examination is identified for survey, and data are gathered to document the current state of practice regarding indicators for patient dose, image quality, and related data elements to characterize general x-ray practice. In this article, we provide an overview of the program’s history and general operational aspects. In a companion article, we will present selected findings from past surveys of CT.