MR‐CT registration using a Ni‐Ti prostate stent in image‐guided radiotherapy of prostate cancer

Korsager, Anne Sofie; Carl, Jesper; Østergaard, Lasse Riis

doi:10.1118/1.4807087

Cited by 6 publications

(8 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mean error was 1.25 mm and the maximum error was 1.86 mm between the four or five anatomical landmarks (10) . The registration error for the automatic registration is more difficult to determine, but was measured in a previous phantom study to be 0.97 mm computed as a root‐mean‐square error (14) . This error was extended with a 95% confidence interval to determine the margin, which was added to the CTV.…”

Section: Resultsmentioning

confidence: 99%

“…It is possible to perform phantom studies to get closer to the ground truth, as in Korsager et al (14) Other studies that have compared registrations in brain imaging (e.g. West et al (22) ) have used landmarks defined on implanted fiducial markers after registrations to calculate the difference in transformations (fiducial registration error), and Sarkar et al (23) used manually defined anatomical landmarks.…”

Section: Discussionmentioning

confidence: 99%

“…The first step was used as an initial alignment and to enable rotational constraints to prevent rotations about the central axis of the stent. Second, a local registration using the rotational constraints was performed based on a manually defined region, which tightly surrounded the prostate stent (14) . The registration was performed using the registration tool minctracc (MINC Tool Kit, McConnell Brain Imaging Centre, Montreal, Canada) (31) …”

Section: Methodsmentioning

confidence: 99%

“…Previous studies have performed local rigid MR‐CT registration of the prostate based on registrations using implanted fiducial markers. Landmark‐based registration, 8 , 9 , 10 segmentation‐based registration, (11) or voxel property‐based registration 12 , 13 , 14 have all been applied. Automatic image registration benefits from objectivity in the registrations as the registration quality is observer‐independent.…”

Section: Introductionmentioning

confidence: 99%

“…The first approach is based on manually defined landmarks on the prostate stent and on the pelvic bones and is now the clinical practice at Aalborg University Hospital (10) . The second approach is an automatic approach using the voxel similarity measure mutual information for a local registration of the prostate stent and a tightly surrounding volume (14) . The comparison was performed by comparing the translational and rotational differences for the CTV volume and anatomical overlap of the CTV between the two approaches.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Comparison of manual and automatic MR‐CT registration for radiotherapy of prostate cancer

Korsager

Carl

Østergaard

2016

J Applied Clin Med Phys

Self Cite

View full text Add to dashboard Cite

In image‐guided radiotherapy (IGRT) of prostate cancer, delineation of the clinical target volume (CTV) often relies on magnetic resonance (MR) because of its good soft‐tissue visualization. Registration of MR and computed tomography (CT) is required in order to add this accurate delineation to the dose planning CT. An automatic approach for local MR‐CT registration of the prostate has previously been developed using a voxel property‐based registration as an alternative to a manual landmark‐based registration. The aim of this study is to compare the two registration approaches and to investigate the clinical potential for replacing the manual registration with the automatic registration. Registrations and analysis were performed for 30 prostate cancer patients treated with IGRT using a Ni‐Ti prostate stent as a fiducial marker. The comparison included computing translational and rotational differences between the approaches, visual inspection, and computing the overlap of the CTV. The computed mean translational difference was 1.65, 1.60, and 1.80 mm and the computed mean rotational difference was 1.51°, 3.93°, and 2.09° in the superior/inferior, anterior/posterior, and medial/lateral direction, respectively. The sensitivity of overlap was 87%. The results demonstrate that the automatic registration approach performs registrations comparable to the manual registration.PACS number(s): 87.57.nj, 87.61.‐c, 87.57.Q‐, 87.56.J‐

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Comparison of manual and automatic MR‐CT registration for radiotherapy of prostate cancer

Korsager

Carl

Østergaard

2016

J Applied Clin Med Phys

Self Cite

View full text Add to dashboard Cite

show abstract

An adaptive MR-CT registration method for MRI-guided prostate cancer radiotherapy

et al. 2015

View full text Add to dashboard Cite

Magnetic Resonance images (MRI) have superior soft tissue contrast compared with CT images. Therefore, MRI might be a better imaging modality to differentiate the prostate from surrounding normal organs. Methods to accurately register MRI to simulation CT images are essential, as we transition the use of MRI into the routine clinic setting. In this study, we present a finite element method (FEM) to improve the performance of a commercially available, B-spline-based registration algorithm in the prostate region. Specifically, prostate contours were delineated independently on ten MRI and CT images using the Eclipse treatment planning system. Each pair of MRI and CT images was registered with the B-spline-based algorithm implemented in the VelocityAI system. A bounding box that contains the prostate volume in the CT image was selected and partitioned into a tetrahedral mesh. An adaptive finite element method was then developed to adjust the displacement vector fields (DVFs) of the B-spline-based registrations within the box. The B-spline and FEM-based registrations were evaluated based on the variations of prostate volume and tumor centroid, the unbalanced energy of the generated DVFs, and the clarity of the reconstructed anatomical structures. The results showed that the volumes of the prostate contours warped with the B-spline-based DVFs changed 10.2% on average, relative to the volumes of the prostate contours on the original MR images. This discrepancy was reduced to 1.5% for the FEM-based DVFs. The average unbalanced energy was 2.65 and 0.38 mJ/cm3, and the prostate centroid deviation was 0.37 and 0.28 cm, for the B-spline and FEM-based registrations, respectively. Different from the B-spline-warped MR images, the FEM-warped MR images have clear boundaries between prostates and bladders, and their internal prostatic structures are consistent with those of the original MR images. In summary, the developed adaptive FEM method preserves the prostate volume during the transformation between the MR and CT images and improves the accuracy of the B-spline registrations in the prostate region. The approach will be valuable for development of high-quality MRI-guided radiation therapy.

show abstract

A MRI-CT prostate registration using sparse representation technique

Yang

Jani

Rossi

et al. 2016

Medical Imaging 2016: Image-Guided Procedures, Robotic Interventions, and Modeling

View full text Add to dashboard Cite

In this paper, we propose a new patch-based initial deformation prediction framework for MRI-CT prostate registration. The sparse representation technique is used to estimate the initial deformation between MRI and CT images in a patch-wise fashion. This method can be further refined by many of the existing registration methods after providing a predicted field for initializing prostate MRI-CT registration. Our registration technique was validated with a clinical study of 9 prostate-cancer patients. Our proposed registration was compared with the current intensity-based registration method. This initial investigation of the prostate MRI-CT registration approach using patch-based deformation demonstrated its clinical feasibility as well as its accuracy.

show abstract

MR‐CT registration using a Ni‐Ti prostate stent in image‐guided radiotherapy of prostate cancer

Abstract: This study demonstrated the feasibility for an automatic local MR-CT registration using the prostate stent.

Cited by 6 publications

References 45 publications

Comparison of manual and automatic MR‐CT registration for radiotherapy of prostate cancer

Comparison of manual and automatic MR‐CT registration for radiotherapy of prostate cancer

An adaptive MR-CT registration method for MRI-guided prostate cancer radiotherapy

A MRI-CT prostate registration using sparse representation technique

Contact Info

Product

Resources

About