Algorithms for optimal sequencing of dynamic multileaf collimators

Kamath, Srijit; Sahni, Sartaj; Palta, Jatinder; Ranka, Sanjay

doi:10.1088/0031-9155/49/1/003

Cited by 38 publications

(25 citation statements)

References 23 publications

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“…( 23 – 25 ) In this paper, only the important issues are highlighted. The first task of the algorithm is to use a function to convert a matrix of dose values into a matrix of exposure times; that is, based on the dose rate, the function determines the duration of time that each sample point must be exposed to radiation.…”

Section: Methodsmentioning

confidence: 99%

SWIMRT: A graphical user interface using the sliding window algorithm to construct a fluence map machine file

Chow

Григоров

Yazdani

2006

J Applied Clin Med Phys

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A custom‐made computer program, SWIMRT, to construct “multileaf collimator (MLC) machine” file for intensity‐modulated radiotherapy (IMRT) fluence maps was developed using MATLAB® and the sliding window algorithm. The user can either import a fluence map with a graphical file format created by an external treatment‐planning system such as Pinnacle3 or create his or her own fluence map using the matrix editor in the program. Through comprehensive calibrations of the dose and the dimension of the imported fluence field, the user can use associated image‐processing tools such as field resizing and edge trimming to modify the imported map. When the processed fluence map is suitable, a “MLC machine” file is generated for our Varian 21 EX linear accelerator with a 120‐leaf Millennium MLC. This machine file is transferred to the MLC console of the LINAC to control the continuous motions of the leaves during beam irradiation. An IMRT field is then irradiated with the 2D intensity profiles, and the irradiated profiles are compared to the imported or modified fluence map. This program was verified and tested using film dosimetry to address the following uncertainties: (1) the mechanical limitation due to the leaf width and maximum traveling speed, and (2) the dosimetric limitation due to the leaf leakage/transmission and penumbra effect. Because the fluence map can be edited, resized, and processed according to the requirement of a study, SWIMRT is essential in studying and investigating the IMRT technique using the sliding window algorithm. Using this program, future work on the algorithm may include redistributing the time space between segmental fields to enhance the fluence resolution, and readjusting the timing of each leaf during delivery to avoid small fields. Possible clinical utilities and examples for SWIMRT are given in this paper.PACS numbers: 87.53.Kn, 87.53.St, 87.53.Uv

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Section: Methodsmentioning

confidence: 99%

SWIMRT: A graphical user interface using the sliding window algorithm to construct a fluence map machine file

Chow

Григоров

Yazdani

2006

J Applied Clin Med Phys

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“…The static case is later on improved by Engel (2005) in his TNMU algorithm. Kamath et al (2004a) revise the algorithm of Ma et al (1998) for the dynamic collimation and provide a simpler proof of the optimality.…”

Section: Unconstrained Dynamic Multileaf Collimationmentioning

confidence: 99%

Mathematical optimization in intensity modulated radiation therapy

et al. 2009

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The design of an intensity modulated radiotherapy treatment includes the selection of beam angles (geometry problem), the computation of an intensity map for each selected beam angle (intensity problem), and finding a sequence of configurations of a multileaf collimator to deliver the treatment (realization problem). Until the end of the last century research on radiotherapy treatment design has been published almost exclusively in the medical physics literature. However, since then, the attention of researchers in mathematical optimization has been drawn to the area and important progress has been made. In this paper we survey the use of optimization models, methods, and theories in intensity modulated radiotherapy treatment design. This is an updated version of the paper that appeared in 4OR, 6(3), 199-262 (2008).

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“…For the intensity profiles with single rows they prove the existence of profiles for which there are feasible plans using static collimation, but no feasible plans with dynamic MLC. Kamath et al (2004a) also present an iterative correction algorithm for the realization of 2 dimensional intensity profiles with interdigitation constraints. The optimality of this correction method for the beam-on time is provided together with the finiteness of the number of iterations.…”

Section: Constrained Dynamic Multileaf Collimationmentioning

confidence: 99%