ABSTRACT
Primary is the radiation in the direct beam itself, scatter is the radiation scattered from the patient, and leakage is the radiation escaping through the head and waveguide assembly of the linac itself. To put the dose limits in context it is useful to know the rates of background exposure radiation due to natural sources such as cosmic rays. The radiation weighting factor accounts of the relative biological effect of the radiation type in question. Dose equivalent itself is a useful quantity but it will not fully account for the effect of radiation exposure on an organism. In radiation therapy and diagnostic rooms shielding is required in order to keep the dose to the surrounding areas within acceptable limits. This report provides a clear and readable presentation of issues related to shielding as well as a wealth of data to enable calculations.
