scope:

These indirect methods involve the determination of absorbed dose in a phantom and the report constitutes a set of working rules, which can be accepted generally for this purpose.

Four stages are usually involved in the establishment of the absorbed dose at any point in a patient. First, a determination of the radiation is made at the calibration point. Second, the peak absorbed dose rate or, for low energies, the surface absorbed dose rate is deduced either by relative measurements, or more usually, with the aid of published depth dose tables. Third, the absorbed dose rate at any point of interest is related to the peak or surface absorbed dose rate. Finally, allowance may have to be made for the fact that the shape, size and composition of the patient are different from those of the phantom in which the standard measurements were made. The report deals with the first three stages of this process.