Dose-volume constrained optimization in intensity-modulated radiation therapy treatment planning

We present a novel optimization method to handle dose-volume constraints (DVCs) directly in intensity-modulated radiation therapy (IMRT) treatment planning based on the idea of continuous dynamical methods. Most of the conventional methods are constructed for solving inconsistent inverse problems with, e.g., dose-volume based objective functions, and one expects to obtain a feasible solution that minimally violates the DVCs. We introduce the concept of ‘acceptable’, meaning that there exists a nonempty set of radiation beam weights satisfying the given DVCs, and we resolve the issue that the objective and evaluation are different in the conventional planning approach. We apply the initial-value problem of the proposed dynamical system to an acceptable and inconsistent inverse problem and prove that the convergence to an equilibrium in the acceptable set of solutions is theoretically guaranteed by using the Lyapunov theorem. Indeed, we confirmed that we can obtain acceptable beam weights through numerical experiments using phantom data simulating a clinical setup for an acceptable and inconsistent IMRT planning system.

内容要旨・審査要旨・論文本文の公開:
内容要旨 : LID201510281017.pdf
審査要旨 : LID201510281018.pdf
論文本文 : LID201510281019.pdf
本論文は, 著者Yoshihiro Tanakaの学位論文として提出され, 学位審査・授与の対象となっている。

© 2015 Tanaka et al.; licensee Springer.
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