Atlas-Based Segmentation Improves Consistency and Decreases Time Required for Contouring Postoperative Endometrial Cancer Nodal Volumes

Young, A.; Wortham, A.; Wernick, Iddo K.; Evans, Andrew; Ennis, Ronald D.

doi:10.1016/j.ijrobp.2010.04.063

Cited by 72 publications

(76 citation statements)

References 13 publications

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“…1,4,5,16 Two of these 4,16 address the male pelvis. Lin et al 4 gives the timings for individual structures (femurs, prostate, bladder and rectum) and found broadly similar time savings-the rectum was the structure that showed the least time saving in their study.…”

Section: Discussionmentioning

confidence: 99%

“…Studies have shown that the time saving varies from around 25-50% of the manual outlining time. [1][2][3][4][5] Only one of these studies documents the time saving per structure, and this indicated that the time saved depends on the structure being outlined. 4 Gambacorta et al 5 postulate that for structures where their autocontouring system was unreliable, the correction time becomes important.…”

mentioning

confidence: 99%

“…[1][2][3] However, the evidence for this is limited. Young et al 1 state that although they found autosegmentation software useful for contouring the postoperative endometrial nodal volumes, it was not useful for the vaginal cuff owing to its positional variability.…”

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confidence: 99%

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The utility of atlas-assisted segmentation in the male pelvis is dependent on the interobserver agreement of the structures segmented

Langmack

Perry²,

Sinstead³

et al. 2014

BJR

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Objective: To investigate the relationship between the ability of atlas-based autosegmentation to reduce outlining time in the male pelvis (body, bladder, rectum, femoral heads, prostate and seminal vesicles) and the interobserver agreement in the delineation of these structures. To examine any increase of the interobserver agreement with the use of an autosegmentation tool. Methods: We created atlases in the ABAS™ system v. 2.0 (Elekta, Crawley, UK) and recorded the time to delineate the above structures on eight patients with and without its aid. We also measured the interobserver agreement in the structure definitions using several metrics [Dice's similarity coefficient (DSC), mean distance to conformity, percentage volume difference] with and without the aid of ABAS. Results: There is a high degree of correlation between the time saving with the use of ABAS and the degree of interobserver agreement (r 5 0.90 for DSC). This indicates that for structures where the interobserver agreement is low (DSC , 0.65), the ABAS does not reduce outlining time. We found that the interobserver agreement is increased with ABAS only for the prostate. Conclusion: Outlining time saved in the male pelvis is highly correlated with the interobserver agreement of the structures. Only for the prostate does the use of ABAS significantly reduce the amount of interobserver variation in contouring. Advances in knowledge: The use of autosegmentation software increases the outlining time for structures where the interobserver agreement is low. Any increase in the interobserver agreement in contouring with the aid of such software may be limited to those structures where there is currently mid-range agreement between observers.The use of automated segmentation tools has been extensively studied. One advantage of the use of such software is to reduce the time spent contouring. Studies have shown that the time saving varies from around 25-50% of the manual outlining time.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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The utility of atlas-assisted segmentation in the male pelvis is dependent on the interobserver agreement of the structures segmented

Langmack

Perry²,

Sinstead³

et al. 2014

BJR

View full text Add to dashboard Cite

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“…A point‐to‐point map generated by deformable image registration transfers structures from the atlas onto the subject dataset. In clinical evaluation studies, 13 , 14 , 15 , 16 , 17 , 18 this approach has been shown to be superior to classical methods on structures that do not have a clear border, as their location is deduced from the atlas. The key element in this approach, however, is the accuracy of the deformable registration algorithm that is used to identify corresponding organs.…”

Section: Introductionmentioning

confidence: 99%

“…The technique has been reported for segmenting the bronchial plexus in lung cancer therapy by Yang et al (28) In general, systematic evaluations of the atlas segmentation concept for brain, and head and neck, anatomy in clinical practice have characterized the approach as a robust and reliable (16) method for providing rapid delineation of target and normal tissues (20) with a favorable balance of accuracy and robustness (29) . Additionally, this method has been shown to decrease interobserver variability 17 , 20 with measurable consistency and time savings, (13) reducing segmentation times by 35% (17) to 63% (20) …”

Section: Introductionmentioning

confidence: 99%

Multiatlas segmentation of thoracic and abdominal anatomy with level set‐based local search

Schreibmann

Marcus

Fox

2014

J Applied Clin Med Phys

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Segmentation of organs at risk (OARs) remains one of the most time‐consuming tasks in radiotherapy treatment planning. Atlas‐based segmentation methods using single templates have emerged as a practical approach to automate the process for brain or head and neck anatomy, but pose significant challenges in regions where large interpatient variations are present. We show that significant changes are needed to autosegment thoracic and abdominal datasets by combining multi‐atlas deformable registration with a level set‐based local search. Segmentation is hierarchical, with a first stage detecting bulk organ location, and a second step adapting the segmentation to fine details present in the patient scan. The first stage is based on warping multiple presegmented templates to the new patient anatomy using a multimodality deformable registration algorithm able to cope with changes in scanning conditions and artifacts. These segmentations are compacted in a probabilistic map of organ shape using the STAPLE algorithm. Final segmentation is obtained by adjusting the probability map for each organ type, using customized combinations of delineation filters exploiting prior knowledge of organ characteristics. Validation is performed by comparing automated and manual segmentation using the Dice coefficient, measured at an average of 0.971 for the aorta, 0.869 for the trachea, 0.958 for the lungs, 0.788 for the heart, 0.912 for the liver, 0.884 for the kidneys, 0.888 for the vertebrae, 0.863 for the spleen, and 0.740 for the spinal cord. Accurate atlas segmentation for abdominal and thoracic regions can be achieved with the usage of a multi‐atlas and perstructure refinement strategy. To improve clinical workflow and efficiency, the algorithm was embedded in a software service, applying the algorithm automatically on acquired scans without any user interaction.PACS numbers: 87.57.nm, 87.57.N‐, 87.57.Q‐

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Methodological approach to create an atlas using a commercial auto‐contouring software

Casati

Piffer

Calusi

et al. 2020

J Applied Clin Med Phys

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The aim of this work was to establish a methodological approach for creation and optimization of an atlas for auto-contouring, using the commercial software MIM MAESTRO (MIM Software Inc. Cleveland OH). Methods: A computed tomography (CT) male pelvis atlas was created and optimized to evaluate how different tools and options impact on the accuracy of automatic segmentation. Pelvic lymph nodes (PLN), rectum, bladder, and femurs of 55 subjects were reviewed for consistency by a senior consultant radiation oncologist with 15 yr of experience. Several atlas and workflow options were tuned to optimize the accuracy of auto-contours. The deformable image registration (DIR), the finalization method, the k number of atlas best matching subjects, and several postprocessing options were studied. To test our atlas performances, automatic and reference manual contours of 20 test subjects were statistically compared based on dice similarity coefficient (DSC) and mean distance to agreement (MDA) indices. The effect of field of view (FOV) reduction on auto-contouring time was also investigated. Results: With the optimized atlas and workflow, DSC and MDA median values of bladder, rectum, PLN, and femurs were 0.91 and 1.6 mm, 0.85 and 1.6 mm, 0.85 and 1.8 mm, and 0.96 and 0.5 mm, respectively. Auto-contouring time was more than halved by strictly cropping the FOV of the subject to be contoured to the pelvic region. Conclusion: A statistically significant improvement of auto-contours accuracy was obtained using our atlas and optimized workflow instead of the MIM Software pelvic atlas.

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Atlas-Based Segmentation Improves Consistency and Decreases Time Required for Contouring Postoperative Endometrial Cancer Nodal Volumes

Cited by 72 publications

References 13 publications

The utility of atlas-assisted segmentation in the male pelvis is dependent on the interobserver agreement of the structures segmented

The utility of atlas-assisted segmentation in the male pelvis is dependent on the interobserver agreement of the structures segmented

Multiatlas segmentation of thoracic and abdominal anatomy with level set‐based local search

Methodological approach to create an atlas using a commercial auto‐contouring software

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