A model and reference data for retrospective dose assessment of organ doses (red bone marrow, lymphatic system) in diagnostic radiography and nuclear medicine, 1946-1995.

Retrospective dosimetry for radiologic and nuclear medicine examinations has been a challenge both for individual patients and in epidemiologic studies. Methodological problems include the large range of patient exposures from radiologic examinations, which spans over three orders of magnitude, the considerable dose reduction over time for most types of examinations due to technical advancements, and the increasing concern for radiation protection and quality issues in radiologic practice. A three-step model for retrospective dosimetry for patient exposure is presented that allows determination of organ doses to the red bone marrow and the lymphatic tissue, respectively, for typical examinations over the time period 1946-1995. The model starts from a set of doses assuming ideal technical equipment and radiologic practice. Step II considers the advancement of technical equipment over the different decades since the introduction of medical radiology in the early 1940's. Step III refers to quality in radiologic routine and allows for adjustment for less-than-ideal standards of radiologic practice. Model parameters are derived from contemporary literature and a multitude of historical sources. Tables with reference data are provided that allow a straightforward application of the model in the context of analytic epidemiologic studies. Wherever possible, reference doses are based on dose area product to allow for easy adjustment to different settings and inclusion of prospective data. The model and the results can be readily extended to different countries with different technical advancement and standard of radiologic practice.