Do Tumors in the Lung Deform During Normal Respiration? An Image Registration Investigation

Wu, Joanne; Peng, Lei; Shekhar, Raj; Li, Huiling; Suntharalingam, Mohan; D’Souza, W

doi:10.1016/j.ijrobp.2009.03.008

Cited by 43 publications

(37 citation statements)

References 25 publications

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“…As noted by others, 20,31 it is uncommon to find tumors undergo both large translational movements and large deformation. The two clinical cases show both translation and deformation but neither is large.…”

Section: Iib Data Acquisition and Processingmentioning

confidence: 78%

Four‐dimensional intensity‐modulated radiation therapy planning for dynamic tracking using a direct aperture deformation (DAD) method

Gui

Feng

et al. 2010

Medical Physics

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Purpose: Planning for the delivery of intensity-modulated radiation therapy ͑IMRT͒ to a moving target, referred to as four-dimensional ͑4D͒ IMRT planning, is a crucial step for achieving the treatment objectives for sites that move during treatment delivery. The authors proposed a simplistic method that accounts for both rigid and nonrigid respiration-induced target motion based on 4D computed tomography ͑4DCT͒ data sets. Methods: A set of MLC apertures and weights was first optimized on a reference phase of a 4DCT data set. At each beam angle, the apertures were morphed from the reference phase to each of the remaining phases according to the relative shape changes in the beam's eye view of the target. Three different planning schemes were evaluated for two lung cases and one pancreas patient: ͑1͒ Individually optimizing each breathing phase; ͑2͒ optimizing the reference phase and shifting the optimized apertures to other breathing phases based on a rigid-body image registration; and ͑3͒ optimizing the reference phase and deforming the optimized apertures to the other phases based on the deformation and translation of target contours. Planning results using scheme 1 serves as the "gold standard" for plan quality assessment; scheme 2 is the method previously proposed in the literature; and scheme 3 is the method the authors proposed in this article. The optimization results were compared between the three schemes for all three cases. Results: The proposed scheme 3 is comparable to scheme 1 in plan quality, and provides improved target coverage and conformity with similar normal tissue dose compared with scheme 2. Conclusions: Direct aperture deformation method for 4D IMRT planning improves upon methods that only consider rigid-body motion and achieves a plan quality close to that optimized for each of the phases.

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Section: Iib Data Acquisition and Processingmentioning

confidence: 78%

Four‐dimensional intensity‐modulated radiation therapy planning for dynamic tracking using a direct aperture deformation (DAD) method

Gui

Feng

et al. 2010

Medical Physics

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“…Even if small, deformations of the lesions and the surrounding parenchyma could potentially alter the results of our analysis. Although Wu et al ( 18 ) previously reported that lung tumors are primarily subject to translation rather than rotation and deformation, it is possible that some of the apparent migration may be due to deformation from breathing.…”

Section: Discussionmentioning

confidence: 97%

Migration of implanted markers for image‐guided lung tumor stereotactic ablative radiotherapy

Hong

Eclov

et al. 2013

J Applied Clin Med Phys

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The purpose of this study was to quantify postimplantation migration of percutaneously implanted cylindrical gold seeds (“seeds”) and platinum endovascular embolization coils (“coils”) for tumor tracking in pulmonary stereotactic ablative radiotherapy (SABR). We retrospectively analyzed the migration of markers in 32 consecutive patients with computed tomography scans postimplantation and at simulation. We implanted 147 markers (59 seeds, 88 coils) in or around 34 pulmonary tumors over 32 procedures, with one lesion implanted twice. Marker coordinates were rigidly aligned by minimizing fiducial registration error (FRE), the root mean square of the differences in marker locations for each tumor between scans. To also evaluate whether single markers were responsible for most migration, we aligned with and without the outlier causing the largest FRE increase per tumor. We applied the resultant transformation to all markers. We evaluated migration of individual markers and FRE of each group. Median scan interval was 8 days. Median individual marker migration was 1.28 mm (interquartile range [IQR] 0.78−2.63 mm). Median lesion FRE was 1.56 mm (IQR 0.92−2.95 mm). Outlier identification yielded 1.03 mm median migration (IQR 0.52−2.21 mm) and 1.97 mm median FRE (IQR 1.44−4.32 mm). Outliers caused a mean and median shift in the centroid of 1.22 and 0.80 mm (95th percentile 2.52 mm). Seeds and coils had no statistically significant difference. Univariate analysis suggested no correlation of migration with the number of markers, contact with the chest wall, or time elapsed. Marker migration between implantation and simulation is limited and unlikely to cause geometric miss during tracking.PACS number: 87.57.N‐; 87.57.nm; 87.53.Ly

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“…This motion error that is known as intra-fractional organs motion error may lead to a significant uncertainty of tumor localization. Therefore, a great amount of over or under dosage is happened onto tumor, and healthy surrounding tissues may receive high dose that is far away from prescribed dose that has been determined before irradiation [8][9][10][11][12][13][14]. Apart from intra-fraction motion error, we face with another motion error known as inter-fraction motion that refers to patient body displacement on treatment couch.…”

Section: Introductionmentioning

confidence: 99%

Motion Challenge of Thoracic Tumors at Radiotherapy by Introducing an Available Compensation Strategy

Torshabi¹,

Dastyar²

2017

Radiotherapy

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In this chapter a description is explained about radiotherapy as common available method in treatment of thoracic tumors located at thorax region of patient body and move mainly due to respiration. In radiotherapy of dynamic tumors, the correct and accurate information of tumor position during the therapeutic irradiation determine the degree of treatment success. In this chapter we investigate quantitatively the effect of tumor motion on treatment quality by considering to possible drawbacks and errors at external surrogate's radiotherapy as clinical treatment modality. For this aim, tumor motion information of a group of real patients treated with Cybeknife Synchrony system (from Georgetown University Hospital) was taken into account. A fuzzy logic based correlation model was employed for tumor motion tracking. Final results represent graphically the amount of tumor motion estimated by our utilized correlation model on three dimensions with targeting error calculation. It's worth mentioning that each strategy that can improve targeting accuracy of dynamic tumors may strongly enhance treatment quality by saving healthy tissues against additional high dose. In this chapter we just tried to introduce readers with thoracic tumor motion error as challenging issue in radiotherapy and motion compensation solutions, implemented clinically up to now.

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Do Tumors in the Lung Deform During Normal Respiration? An Image Registration Investigation

Cited by 43 publications

References 25 publications

Four‐dimensional intensity‐modulated radiation therapy planning for dynamic tracking using a direct aperture deformation (DAD) method

Four‐dimensional intensity‐modulated radiation therapy planning for dynamic tracking using a direct aperture deformation (DAD) method

Migration of implanted markers for image‐guided lung tumor stereotactic ablative radiotherapy

Motion Challenge of Thoracic Tumors at Radiotherapy by Introducing an Available Compensation Strategy

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