| Popis: |
In this paper, a relatively new computationally efficient technique, called model predictive static programming (MPSP), is extended further to incorporate a sequence of 'impulse' control inputs, which is subsequently used to propose an effective suboptimal automatic feedback radiotherapy strategy. A realistic two compartment kinetic model with oxygen effect is considered for computing the control sequence. Biologically effective dose constraints on early and late normal tissue are also considered. The proposed strategy essentially drives the radius of a tumor below the radius of a single cell, thereby driving the number of cancer cells to 'zero'. Time interval between impulses is taken as 8 hrs and it is found that the tumor is driven to zero with approximately 25 impulses. Note that the MPSP algorithm is computationally quite efficient and it takes only 3-4 min in a regular desktop and MATLAB environment. |
