A 3D Correction Method for Pencil Beam Dose Calculation in Pulmonary Radiotherapy

Abstract

The invention discloses a three-dimensional correction method for pencil beam dose calculation in the case of lung radiotherapy, which comprises steps: first CT (Computed Tomography) data of a healthy human lung are acquired; the first CT data are converted into phantom data for calculation of a Monte Carlo calculation program; absorbed doses of the phantom data are calculated and a corresponding feature array is acquired; different weights are given to elements in the feature array according to an adjacent relationship with a central element; coding is carried out on the feature arrays; second CT data of a tumor patient lung are calculated by using pencil beam algorithm in a radiotherapy planning system, dose information is extracted from a dose file derived from the radiotherapy planning system, and a three-dimensional dose array is built by the extracted dose information; coding is carried out on the three-dimensional dose array; the coded three-dimensional dose array corresponds to the coded feature array, and a mapping relationship is built; and a convolution formula with weights and the mapping relationship are used for carrying out convolution processing on the three-dimensional dose array, and a corrected pencil beam three-dimensional dose array is obtained.

Description

technical field [0001] The invention relates to the technical field of radiotherapy, in particular to a three-dimensional correction method for pencil beam dose calculation in lung radiotherapy. Background technique [0002] Most of the existing radiotherapy planning systems use the analytical dose calculation method, but the biggest problem with the analytical dose calculation method is the inaccurate calculation of energy deposition in inhomogeneous tissues. The ray direction is corrected one-dimensionally. In particular, the pencil beam dose calculation method has a significant error in the dose calculation of the beam edge and the area where the value of computer X-ray tomography (Computed Tomography; CT) changes greatly. However, because the pencil beam algorithm is particularly suitable for the reverse optimization algorithm of the current intensity-modulated conformal radiotherapy, it can significantly improve the speed of optimization, so both research institutions ...

AI Technical Summary

Problems solved by technology

However, this method has the problem of long calculation time and cannot meet the clinical needs.

Although many researchers use multi-thread acceleration or GPU hardware acceleration to increase the calculation speed of the Monte Carlo method, they also face the problem that they cannot provide a reasonable improvement plan for the radiotherapy planning system that has been used in clinical practice.

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