DOSE-VOLUME DISTRIBUTIONS - A NEW APPROACH TO DOSE-VOLUME HISTOGRAMS IN 3-DIMENSIONAL TREATMENT PLANNING

A new approach to calculating and displaying dose-volume relationships in 3D radiation therapy is presented. We have developed a concept of a dose-volume distribution (DVD) and its corresponding differential do se-volume distribution (DDVD), based on organization of the data in th e volume rather than in the dose domain. The new concepts make full us e of the information that can be obtained from the dose calculation po ints and the sampling pattern and are designed to overcome shortcoming s of the classical concepts of dose-volume histograms (DVH) and differ ential dose-volume histograms (DDVH). The new concepts can be applied to any number of dose calculation points, but they are especially adva ntageous when a small number of points is used. DVDs are particularly well suited to pseudo- and quasirandom sampling of dose distributions. We have developed an error analysis for DVDs and DDVDs in the case of pseudorandom sampling. We also describe an adaptive technique for min imizing the amount of data needed for purposes of display.