| Abstrakt: |
The principles of mathematical modeling of optimal dose fields in contact radiotherapy (RT) of malignant tumors are investigated. The point dose additivity provides for presetting the permissible dose field in an irradiated organism as a system of linear limitations to doses in the control points (CP) distributed in the lesion focus and in healthy organs and tissues. It was shown as impossible to shape a dose field by linear limitations to doses in CP in using the RT contact methods with the irradiation sources being implanted into lesion focus. A mathematic interpretation was suggested for the task (with its solution by an iterative algorithm) of forming an optimal dose field in the lesion focus with implanted irradiation sources, which is based on maximizing the factor of dose-field homogeneity. It was further demonstrated that linear limitations, if added to the dose in healthy organs and tissues, make the task even more complicated if not insoluble. Finally, it is suggested to use the method of shaping an effective dose field by the iterative method with interactive visual optimization of the dose field. |
