Contouring is the act of defining the borders of normal organs, and results in the production of the CTV which is THE MOST IMPORTANT CLINICAL VOLUME DEFINED by the radiation oncologist, as this is the area corresponding to disease risk and organ exclusion. Too large and there are too many side effects, too small and disease eradication cannot be reliably achieved (Rischin & Peters paper on effect of poor compliance with protocol)
There are increasingly accurate data being presented to inform this process in the H&N, the pelvis and chest. There can be no excuses for radiation oncologists NOT undertaking this type of voluming as the tools are available and the publications are not new any more.
Gynaecological voluming of the pelvis