Functional avoidance of lung in plan optimization with an aperture-based inverse planning system

St-Hilaire, J.; Lavoie, Caroline; Dagnault, Anne; Beaulieu, F.; Morin, Fannie; Beaulieu, Luc; Tremblay, Daniel

doi:10.1016/j.radonc.2011.09.003

Cited by 27 publications

(35 citation statements)

References 30 publications

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“…Functional planning methods have developed over time in tandem with improvements to treatment planning systems, from initial SPECT studies that used conventional plans with manually modified beam orientations [4,102,103]; to conformal (3D-CRT) planning [5,16,99,104], including a comparison of coplanar and non-coplanar fields [104]; and comparison of 3D-CRT and intensity modulated radiotherapy (IMRT) [105 107]; and a number of IMRT studies that have used between 3-10 beams [5,15,17 voxel-wise functional planning may prove a more useful option [111,115].…”

Section: Planning Studiesmentioning

confidence: 99%

“…Absolute reductions in functional V20 range from no significant difference [104,111] and 3-7% for SPECT [107,109,110,113,114]; no significant difference [16] and 4% for perfusion PET but no significant difference when using ventilation PET [15]; 2-3% for MRI [17,60,62]; and no significant difference [99 101,112] and 5% for CT-based methods [33,96,98,97] (Table 1). However, comparison between studies is complicated by the diverse methodology employed, including patient characteristics, planning techniques, segmentation and definition of functional regions, image registration and other image processing, and a lack of consistency in the use and reporting of statistical analysis.…”

Section: Planning Studiesmentioning

confidence: 99%

“…However, in some cases the optimisation of beam angles can eliminate significant differences between anatomical and functional plans obtained from fixed beam-only plans [98]. Interestingly, the largest functional V20 differences of 5-7% have been found when using fixed beams [96,98,109,113] in contrast to optimised beam angles which tend to produce 2-3% differences [17,60,99,107,97], although both methods have also produced a large number of cases with no significant difference due to additional functional data [5,98,100,104,105,111].…”

Section: Planning Studiesmentioning

confidence: 99%

“…Further, PET/CT has been registered to 4D-CT [125]. Ideally, the same immobilisation technique [4,15,113] and a flat bed [15, 104,106,111] should be used for both image acquisitions.…”

Section: Image Acquisition and Registration Protocols For Functional mentioning

confidence: 99%

“…The gains brought about through successively more conformal and computationally optimised plans [130 132] may diminish returns from further optimisation due to functional data and several studies have shown no significant benefit for the majority of patients examined [5,98,100,104,105,111]. …”

Section: Potential Limitations Of Normal Lung Avoidancementioning

confidence: 99%

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Functional Image-guided Radiotherapy Planning for Normal Lung Avoidance

et al. 2016

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ReuseThis article is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs (CC BY-NC-ND) licence. This licence only allows you to download this work and share it with others as long as you credit the authors, but you can't change the article in any way or use it commercially. More information and the full terms of the licence here: https://creativecommons.org/licenses/ Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. 1 AbstractFor patients with lung cancer undergoing curative intent radiotherapy, functional lung imaging can be incorporated into treatment planning to modify the dose distribution within non-target volume lung by differentiation of lung regions that are functionally defective or viable. This concept of functional image-guided lung avoidance treatment planning has been investigated with several imaging modalities, primarily SPECT but also hyperpolarised gas MRI, PET and CT-based measures of lung biomechanics. Here, we review the application of each of these modalities, review practical issues of lung avoidance implementation, including image registration and the role of both ventilation and perfusion imaging, and provide guidelines for reporting of future lung avoidance planning studies.

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Section: Planning Studiesmentioning

confidence: 99%

Section: Planning Studiesmentioning

confidence: 99%

Section: Planning Studiesmentioning

confidence: 99%

“…Further, PET/CT has been registered to 4D-CT [125]. Ideally, the same immobilisation technique [4,15,113] and a flat bed [15, 104,106,111] should be used for both image acquisitions.…”

Section: Image Acquisition and Registration Protocols For Functional mentioning

confidence: 99%

Section: Potential Limitations Of Normal Lung Avoidancementioning

confidence: 99%

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Functional Image-guided Radiotherapy Planning for Normal Lung Avoidance

et al. 2016

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A complete 4DCT‐ventilation functional avoidance virtual trial: Developing strategies for prospective clinical trials

Waxweiler

Schubert

Diot

et al. 2017

J Applied Clin Med Phys

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Introduction4DCT-ventilation is an exciting new imaging modality that uses 4DCT data to calculate lung-function maps. Because 4DCTs are acquired as standard of care for lung cancer patients undergoing radiotherapy, 4DCT-ventiltation provides functional information at no extra dosimetric or monetary cost to the patient. The development of clinical trials is underway to use 4DCT-ventilation imaging to spare functional lung in patients undergoing radiotherapy. The purpose of this work was to perform a virtual trial using retrospective data to develop the practical aspects of a 4DCT-ventilation functional avoidance clinical trial.MethodsThe study included 96 stage III lung cancer patients. A 4DCT-ventilation map was calculated using the patient’s 4DCT-imaging, deformable registration, and a density-change-based algorithm. Clinical trial inclusion assessment used quantitative and qualitative metrics based on the patient’s spatial ventilation profile. Clinical and functional plans were generated for 25 patients. The functional plan aimed to reduce dose to functional lung while meeting standard target and critical structure constraints. Standard and dose-function metrics were compared between the clinical and functional plans.ResultsOur data showed that 69% and 59% of stage III patients have regional variability in function based on qualitative and quantitative metrics, respectively. Functional planning demonstrated an average reduction of 2.8 Gy (maximum 8.2 Gy) in the mean dose to functional lung.ConclusionsOur work demonstrated that 60–70% of stage III patients would be eligible for functional planning and that a typical functional lung mean dose reduction of 2.8 Gy can be expected relative to standard clinical plans. These findings provide salient data for the development of functional clinical trials.

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Four‐dimensional computed tomography‐based ventilation imaging in intensity‐modulated radiation therapy treatment planning for pulmonary functional avoidance

Iqbal

Zhang

D'Souza

et al. 2023

J Applied Clin Med Phys

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To incorporate four-dimensional computed tomography (4DCT)based ventilation imaging into intensity-modulated radiation therapy (IMRT) treatment planning for pulmonary functional avoidance. Methods and Materials: Nineteen locally advanced lung cancer patients are retrospectively studied. 4DCT images are employed to create ventilation maps for each patient via a density-change-based algorithm with mass correction.The regional ventilation is directly incorporated into the mathematical formulation of a direct aperture optimization model in IMRT treatment planning to achieve functional avoidance and a voxel-based treatment plan.The proposed functional avoidance planning and voxel-based planning are compared to the conventional treatment planning approach purely based on the anatomy of patients. Paired sample t-tests are conducted to see whether dosimetric differences among the three approaches are significant. Results: Similar planning target volume (PTV) coverage is achieved by anatomical, functional avoidance, and voxel-based approaches. The voxelbased treatment planning performs better than both functional avoidance and anatomical planning to the lung. For a total lung, the average volume reductions in a functional avoidance plan from an anatomical plan, a voxel-based plan from an anatomical plan, and a voxel-based plan from a functional avoidance plan are 7.0%,16.8%,and 10.6%,respectively for V 40 ;and 0.4%,6.4%,and 6.0%,respectively for mean Lung Dose (MLD). For a functional lung, the reductions are 8.8%, 17.2%, and 9.2%, respectively, for fV 40 ; and 1.1%, 6.2%, and 5.2%, respectively, for functional mean lung dose (fMLD). These reductions are obtained without significantly increasing doses to other organs-at-risk. All the pairwise treatment planning comparisons for both total lung and functional lung are statistically significant (p-value < 𝛼 = 0.05) except for the functional avoidance plan with the anatomical plan pair in which the p-value > 𝛼 = 0.05. From these results, we can conclude that voxel-based treatment planning outperforms both anatomical and functional-avoidance planning. Conclusions: We propose a treatment planning framework that directly utilizes functional images and compares voxel-based treatment planning with functional avoidance and anatomical treatment planning.

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Functional avoidance of lung in plan optimization with an aperture-based inverse planning system

Cited by 27 publications

References 30 publications

Functional Image-guided Radiotherapy Planning for Normal Lung Avoidance

Functional Image-guided Radiotherapy Planning for Normal Lung Avoidance

A complete 4DCT‐ventilation functional avoidance virtual trial: Developing strategies for prospective clinical trials

Four‐dimensional computed tomography‐based ventilation imaging in intensity‐modulated radiation therapy treatment planning for pulmonary functional avoidance

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