DOSE-VOLUME HISTOGRAM COMPUTATIONS FOR SMALL INTRACRANIAL VOLUMES

A sampling formalism is Presented to accurately compute the absolute v olumes and integral dose-volume histograms of small volumes treated in stereotactic radiosurgery. The presence of small volumes and sharp do se gradients places special constraints on the computational formalism and the accuracy required to compute the dose-volume relationships. W e use a spatially nonuniform random sampling method to allow an effici ent and accurate computation of the dose-volume histograms for an arbi trary number of volumes. The computation of absolute volume vs dose al lows intercomparison of dose delivered to target and dose-critical vol umes and allows a quantitative trade-off analysis often critical to an optimal treatment of the lesion.