Fast Simultaneous Angle, Wedge, and Beam Intensity Optimization in Inverse Radiotherapy Planning

Abstract

We present a new fast radiotherapy planning algorithm which determines approximatively optimal gantry and table angles, kinds of wedges, leaf positions and intensities simultaneously in a global way. Other parameters are optimized only independently of each other. The algorithm uses an elaborate field management and field reduction. Beam intensities are determined via a variant of a projected Newton method of Bertsekas. The objective function is a standard piecewise quadratic penalty function, but it is built with efficient upper bounds which are calculated during the optimization process. Instead of pencil beams, basic leaf positions are included. The algorithm is implemented in the new beam modelling and dose optimization module HOMO OPTIS.

Approximated segmentation considering technical and dosimetric constraints in intensity-modulated radiation therapy with electrons

“…For the detailed evaluation of our algorithms, we use a set of 264 clinical intensity matrices that originate from electron treatment plans for different patients and beam angles. The matrices are produced during the optimization step 1 of the treatment planning that was introduced in Section 5 and uses the algorithm from [9]. Exemplarily, we compute segmentations for the settings f = 3, g 1 = 3 and g 2 = 1 as well as f = 4 and g 1 = g 2 = 2.…”

“…A clinical case was set-up to examine the efficiency of our proposed segmentation algorithms. For a patient with cancer of the right breast, electron irradiation plans using various segmentation settings and different optimization constraints were created with a self-designed IMRT optimization programme based on our previous studies [9]. The planning target volume was the right breast, which should receive a total dose of 50.4 Gy (1.8 Gy per fraction).…”

“…1. Simultaneous optimization of beam orientation, energy and intensity: A set of radiation incidence angles (typically 10-15) is determined given by table and gantry angles [9,24]. For each configuration, the algorithm calculates the optimal fluence distribution, given by a nonnegative integer matrix.…”

Mathematical optimization in intensity modulated radiation therapy

“…Other local search methods are described in, e.g., Craft (2007) and Engel and Tabbert (2005). Next we look at stochastic methods for beam selection.…”

Beam Angle Optimization for Double-Scattering Proton Delivery Technique Using an Eclipse Application Programming Interface and Convolutional Neural Network

“…Thus, various studies for BAO have been conducted to reduce the workload of treatment planning and decrease the planning time. These BAO studies incorporated techniques such as simulated annealing (2)(3)(4)(5)(6)(7)(8)(9), geometric information scoring (10)(11)(12)(13)(14)(15)(16)(17)(18)(19), gradient descent (20)(21)(22)(23)(24)(25), genetic algorithms (26)(27)(28)(29), and neural networks (30)(31)(32)(33)(34). However, the advent of volumetric-modulated arc therapy and the templatization of the radiation treatment plan, including dose prescription and gantry angles, have reduced interest in BAO research for X-ray therapy.…”