Source of Support: None, Conflict of Interest: None
The purpose of this paper is to discuss the dose presentation techniques used to represent three dimensional dose distributions on a commercial treatment planning system, the General Electric Target System. There are two basic techniques for display and presentation of three dimensional dose information for radiotherapy treatment planning. One approach is to produce and display isodose surfaces superimposed on surface representation of patient anatomy. The main benefits from this technique are the immediate recognition of relative geometry within the patient and an overall conceptual understanding of the dose distribution. However, this form of display gives mainly qualitative rather than quantitative information. For example the margin between isodose surface and target surface is only visible around the extreme margins of the target volume. The other more widely applicable technique is to use planar dose displays where the dose distribution is displayed on any plane through the irradiated volume. This technique is typically very much faster than isodose surface displays and can be implemented on hardware configurations of much lower cost and complexity. To achieve the full benefits from three dimensional treatment planning using any form of graphics displays for dose distributions, it is becoming clinician and physicist responsible for patient treatment. We have implemented a volume dose calculation for this purpose which provides the user with tabulated tissue volumes receiving doses in specified ranges. This information is categorised into tissue types, for instance tumour volume, target volume or specified internal structures. The detailed information available from such volume dose statistics will give the clinician a much more thorough understanding of the likely problems associated with the particular treatment.