Dose calculation optimization in intracranial stereotactic radiotherapy using implicit surface modeling

Abstract

Intracranial Stereotactic radiotherapy / radiosurgery utilize fractioned dose delivery through multiple noncoplanar arcs to avoid harm of normal tissue. Proper positioning of the arcs in respect to avoid Organs at Risk irradiation while maintaining high dose distribution at the lesion is frequently a trial and error optimization procedure during treatment planning. Proper geometric modeling of both the irradiation equipment and the patients anatomical structures based on CT image scans can be done combined with special developed data structures to aid the subsequent dose calculation due to beam modifications. Extending implicit surface modeling techniques to represent anatomical structures as well as usage of time stamp controlled data caching led to a dose recalculation speed-up factor of 12 for a single beam in the relocated arc.