The acceptability of a multileaf collimator as a replacement for conventional blocks

Fernandez, E.M.; Shentall, Glyn; Mayles, W. P. M.; Dearnaley, David P.

doi:10.1016/0167-8140(95)01571-w

Cited by 36 publications

(20 citation statements)

References 11 publications

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“…To achieve the appropriate target coverage and respect the dose constraint criteria for organs at risk, both IMRT and VMAT use many irregularly shaped fields defined by multileaf collimators (MLCs). MLCs have been routinely used in radiotherapy over the past 20 years 4, 5. Desirable MLC design characteristics include low intraleaf and interleaf transmission, a small tongue and groove effect, a small leaf width, accurate and fast leaf positioning, and most importantly, reproducibility.…”

Section: Introductionmentioning

confidence: 99%

Agility MLC transmission optimization in the Monaco treatment planning system

Roche

Crane

Powers

et al. 2018

J Applied Clin Med Phys

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The Monaco Monte Carlo treatment planning system uses three‐beam model components to achieve accuracy in dose calculation. These components include a virtual source model (VSM), transmission probability filters (TPFs), and an x‐ray voxel Monte Carlo (XVMC) engine to calculate the dose in the patient. The aim of this study was to assess the TPF component of the Monaco TPS and optimize the TPF parameters using measurements from an Elekta linear accelerator with an Agility™ multileaf collimator (MLC). The optimization began with all TPF parameters set to their default value. The function of each TPF parameter was characterized and a value was selected that best replicated measurements with the Agility™ MLC. Both vendor provided fields and a set of additional test fields were used to create a rigorous systematic process, which can be used to optimize the TPF parameters. It was found that adjustment of the TPF parameters based on this process resulted in improved point dose measurements and improved 3D gamma analysis pass rates with Octavius 4D. All plans calculated with the optimized beam model had a gamma pass rate of > 95% using criteria of 2% global dose/2 mm distance‐to‐agreement, while some plans calculated with the default beam model had pass rates as low as 88.4%. For measured point doses, the improvement was particularly noticeable in the low‐dose regions of the clinical plans. In these regions, the average difference from the planned dose reduced from 4.4 ± 4.5% to 0.9 ± 2.7% with a coverage factor (k = 2) using the optimized beam model. A step‐by‐step optimization guide is provided at the end of this study to assist in the optimization of the TPF parameters in the Monaco TPS. Although it is possible to achieve good clinical results by randomly selecting TPF parameter values, it is recommended that the optimization process outlined in this study is followed so that the transmission through the TPF is characterized appropriately.

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Section: Introductionmentioning

confidence: 99%

Agility MLC transmission optimization in the Monaco treatment planning system

Roche

Crane

Powers

et al. 2018

J Applied Clin Med Phys

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“…7 At that time, there were only a limited number of prototype 3D TP software systems in use 26 and they were still very much being developed in-house. In 1993, Webb 27 listed nine 3D TPS in use internationally most not marketed commercially.…”

Section: Ct Based Treatment Planningmentioning

confidence: 99%

“…In 2001, the Peter MacCallum Cancer Centre in Melbourne, developed an in-house 3D-coregistration software to enable CT and PET images to be coregistered on the CadPlan® TPS and a pilot study to determine the feasibility of using the software shortly followed. 41 Computer-controlled treatment delivery systems, field collimation technology such as asymmetric diaphragms, multileaf collimators (MLC), 7,42 dynamic wedge, and electronic portal imaging (EPI) made it possible to deliver more complex treatments like 3D conformal radiation therapy 23,43,44 and later IMRT. In the Australian context, linear accelerators with most of these capabilities became available from the late 1990s.…”

Section: D Treatment Planningmentioning

confidence: 99%

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2012

Radiographer

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“…Although MLCs have been favourably compared to traditional beamshaping techniques (Fernandez, et al, 1995), they are not used dynamically under clinical conditions. Therefore, in this work the PSCs, which are deduced from the optimised IMB profiles, are used to modulate the beam intensities.…”

Section: Introductionmentioning

confidence: 99%

Improving Physical Selectivity in the Treatment of Cancer: A Systems Modelling and Optimisation Approach

Haas¹,

Burnham²,

Mills³

1997

IFAC Proceedings Volumes

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This paper presents the results arising from a practical implementation of a novel hybrid optimisation scheme, used to solve the inverse problem in radiotherapy treatment planning (RTP). A matrix-based beam model which has been developed making use of a control systems modelling approach is used, together with a hybrid optimisation scheme. Patient-specific compensator profiles are deduced from the intensity modulated beam profiles obtained from the hybrid scheme, with use being made of an exponential attenuation factor coupled with a point spread convolution function to account for the scatter in the compensator. A good agreement between the predicted and actual conformational distributions is achieved.

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The acceptability of a multileaf collimator as a replacement for conventional blocks

Cited by 36 publications

References 11 publications

Agility MLC transmission optimization in the Monaco treatment planning system

Agility MLC transmission optimization in the Monaco treatment planning system

Untitled

Improving Physical Selectivity in the Treatment of Cancer: A Systems Modelling and Optimisation Approach

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