Speed and Efficiency Considerations in the Calculation of Planning Target Volumes (PTV) in Radiation Therapy Planning

摘要

Certain radiation therapy applications require the addition of geometric margins to the Gross Tumor Volume (GTV) or the Clinical Target Volume (CTV), thus resulting in the creation of a new volume commonly referred to as the Planning Target Volume (PTV). The manual procedure to add the required margins to the target in three dimensions could be quite time-consuming. This paper describes a fast algorithm for computing the PTV using a fast Fourier transform (FFT) based convolution. The algorithm is initially developed for a two-dimensional contour. Afterwards, the extension to three-dimensional volumes is explained. Also, a simplified heuristic algorithm for the three dimensional case is given, one which reduces storage requirements for large volumes.