3-D radiation therapy treatment planning: overview and assessment

A 3-D treatment planning system is one that can represent all radiation therapy treatment machine motions, and which can calculate the dose at any point in the patient treatment volume. As a corollary to these two requirements, a 3-D planning system must also be able to display 3-D plan geometry and doses in some useful way. This article reviews three visible aspects of 3-D planning systems: graphic displays, dose computation methods, and ease of use. It also discusses a less visible, but no less important, aspect: the underlying software engineering. Although 3-D planning systems first appeared in research institutions more than a decade ago, and potential benefits have been demonstrated, they are used only rarely in routine clinical practice. This review concludes that adequate displays and computation techniques are now available, but improved packaging, engineering, and ease of use are required before 3-D planning will be practiced widely.