Development of an Optimized Pencil Beam Algorithm for Radiation Therapy

摘要

In radiation therapy in clinical practice short calculation times are naturally desired when calculating the three dimensional dose distribution of high-energetic photon beams. For this purpose we developed a new highly efficient version of a pencil beam convolution algorithm originally devised in ref. |11. Since most of the actual desktop computers provide more than one calculation core we used multithreading extensively to parallelize the workload and thus speedup the algorithmic runtime. On an eight-core Intel Xeon machine the dose distribution of a typical IMRT treatment plan can be calculated in about 10 s. We achieved a high accuracy with an error tolerance of less than two percent against measurements in homogeneous media aside from the dose build-up region. The ability of calculating the dose distribution of unflattened photon beams makes this algorithm also a candidate for stereotactic radiosurgery. Therefore we also implemented this algorithm into an inverse planning system and compared the results of both irradiation types for a large-tumor case.