Improvements in prostate radiotherapy from the customization of beam directions

Rowbottom, C.; Webb, Steve; Oldham, Mark

doi:10.1118/1.598308

Cited by 70 publications

(61 citation statements)

References 32 publications

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“…The optimization of non-coplanar beam angles in 3DCRT and IMRT is generally performed manually by experienced treatment planners, although a considerable body of literature exists on automated beam angle optimization approaches (Bortfeld & Schlegel 1993, Rowbottom et al 1998, Pugachev and Xing 2001, Bangert & Oelfke 2010, Bangert et al 2012.…”

Section: Introductionmentioning

confidence: 99%

Trajectory optimization for dynamic couch rotation during volumetric modulated arc radiotherapy

et al. 2013

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Abstract. Non-coplanar radiation beams are often used in three-dimensional conformal and intensity modulated radiotherapy to reduce dose to organs at risk (OAR) by geometric avoidance. In volumetric modulated arc radiotherapy (VMAT) non-coplanar geometries are generally achieved by applying patient couch rotations to single or multiple full or partial arcs. This paper presents a trajectory optimization method for a non-coplanar technique, dynamic couch rotation during VMAT (DCR-VMAT), which combines ray tracing with a graph search algorithm. Four clinical test cases (partial breast, brain, prostate only, and prostate and pelvic nodes) were used to evaluate the potential OAR sparing for trajectory optimized DCR-VMAT plans, compared with standard coplanar VMAT. In each case, ray tracing was performed and a cost map reflecting the number of OAR voxels intersected for each potential source position was generated. The least-cost path through the cost map, corresponding to an optimal DCR-VMAT trajectory, was determined using Dijkstra's algorithm. Results show that trajectory optimization can reduce dose to specified OARs for plans otherwise comparable to conventional coplanar VMAT techniques. For the partial breast case, the mean heart dose was reduced by 53%. In the brain case, the maximum lens doses were reduced by 61% (left) and 77% (right) and the globes by 37% (left) and 40% (right). Bowel mean dose was reduced by 15% in the prostate only case. For the prostate and pelvic nodes case, the bowel V 50Gy and V 60Gy were reduced by 9% and 45% respectively. Future work will involve further development of the algorithm and assessment of its performance over a larger number of cases in site specific cohorts.

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Section: Introductionmentioning

confidence: 99%

Trajectory optimization for dynamic couch rotation during volumetric modulated arc radiotherapy

et al. 2013

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“…Indeed, incorporation of prior knowledge in the treatment planning process 4 , 5 is an effective method to reduce the lengthy times (6) associated with selecting optimal beam configurations 7 , 8 and dose volume constraints (9) . Wu and colleagues 10 , 11 investigated the use of overlaps between critical structures and the planning volume for predicting achievable DVH.…”

Section: Introductionmentioning

confidence: 99%

Prior‐knowledge treatment planning for volumetric arc therapy using feature‐based database mining

Schreibmann

Fox

2014

J Applied Clin Med Phys

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Treatment planning for volumetric arc therapy (VMAT) is a lengthy process that requires many rounds of optimizations to obtain the best treatment settings and optimization constraints for a given patient's geometry. We propose a feature‐selection search engine that explores previously treated cases of similar anatomy, returning the optimal plan configurations and attainable DVH constraints. Using an institutional database of 83 previously treated cases of prostate carcinoma treated with volumetric‐modulated arc therapy, the search procedure first finds the optimal isocenter position with an optimization procedure, then ranks the anatomical similarity as the mean distance between targets. For the best matching plan, the planning information is reformatted to the DICOM format and imported into the treatment planning system to suggest isocenter, arc directions, MLC patterns, and optimization constraints that can be used as starting points in the optimization process. The approach was tested to create prospective treatment plans based on anatomical features that match previously treated cases from the institution database. By starting from a near‐optimal solution and using previous optimization constraints, the best matching test only required simple optimization steps to further decrease target inhomogeneity, ultimately reducing time spend by the therapist in planning arcs' directions and lengths.PACS number: 87.55.D‐, 87.55.de

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“…Most of the earlier work in the literature uses sequential schemes Gokhale et al 1994;Myrianthopoulos et al 1992;Rowbottom et al 1998Rowbottom et al , 1999, in which a certain number of beam angles are decided first, and their weights are subsequently determined. Rowbottom et al (2001) optimize both variables simultaneously.…”

Section: Optimization Beam Anglesmentioning

confidence: 99%

An Optimization Framework for Conformal Radiation Treatment Planning

Lim

Ferris

Wright

et al. 2007

INFORMS Journal on Computing

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A n optimization framework for three-dimensional conformal radiation therapy is presented. In conformal therapy, beams of radiation are applied to a patient from different directions, where the aperture through which the beam is delivered from each direction is chosen to match the shape of the tumor, as viewed from that direction. Wedge filters may be used to produce a gradient in beam intensity across the aperture. Given a set of equispaced beam angles, a mixed-integer linear program can be solved to determine the most effective angles to be used in a treatment plan, the weight (exposure time) to be used for each beam, and the type and orientation of wedges to be used. Practical solution techniques for this problem are described; they include strengthening of the formulation and solution of smaller approximate problems obtained by a reduced parametrization of the treatment region. In addition, techniques for controlling the dose-volume histogram implicitly for various parts of the treatment region using hot-and cold-spot control parameters are presented. Computational results are given that show the effectiveness of the proposed approach on practical data sets.

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Improvements in prostate radiotherapy from the customization of beam directions

Cited by 70 publications

References 32 publications

Trajectory optimization for dynamic couch rotation during volumetric modulated arc radiotherapy

Trajectory optimization for dynamic couch rotation during volumetric modulated arc radiotherapy

Prior‐knowledge treatment planning for volumetric arc therapy using feature‐based database mining

An Optimization Framework for Conformal Radiation Treatment Planning

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