Principles of cobalt-60 teletherapy including an introduction to the compendium. Physical aspects of cobalt-60 teletherapy

The role of physics in radiotherapy is to convert a qualitative medical intention into a precise, quantitative course of action. The radiotherapist diagnoses the disease and prescribes the treatment in general terms; the physicist translates the prescription into a practical means of delivering the required radiation dose to the designated target volume, without overdosing normal tissues outside that volume. This Compendium focuses on cobalt-60 as a radiation source, to highlight those aspects of cobalt-60 teletherapy that tend to be crowded out of the textbooks - such aspects as the construction of sources and treatment heads and the special problems of radiation protection with radionuclide sources. Finally, the place and limitations of cobalt units as sources of radiation for external beam therapy are discussed. This section is particularly relevant in the light of the current 'accelerator versus cobalt' debate