Atlas-based Segmentation in Prostate IMRT: Timesavings in the Clinical Workflow

Lin, AY; Kubicek, G.J.; Piper, Jonathan; Nelson, Aaron; Dicker, Adam P.; Valicenti, Richard K.

doi:10.1016/j.ijrobp.2008.06.1120

Cited by 13 publications

(19 citation statements)

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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. We found statistically significant reductions in delineation times for all but three structures-the body, rectum and seminal vesicles.…”

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.…”

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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%

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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“…Autocontouring has been shown to improve consistency and efficiency in definitive prostate cancer using the same commercially available software we used (9,10). With institutionally developed software, contouring whole breast volumes required approximately 30% less time, and the consistency of the contours also improved (14).…”

Section: Discussionmentioning

confidence: 99%

“…The contours are then mapped to the patient by deforming those from the matched atlas subject. Atlas-based segmentation has been shown to save contouring time and improve consistency in treatment planning for prostate and head-and-neck cancers (9)(10)(11). This approach could also be valuable for nodal target volume delineation in endometrial cancer patients.…”

Section: Introductionmentioning

confidence: 99%

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

Young

Wortham

Wernick

et al. 2011

International Journal of Radiation Oncology*Biology*Physics

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“…[21][22][23] Another popular method that has often seen commercial implementation is the atlas-based approach that uses the coregistration of a large database of patient scans to produce a probabilistic map of expected uptake values for healthy patients and then uses deviations from this map to determine where abnormal regions lie. 24,25 While there has been a plethora of work regarding proper PET segmentation, the problem remains a challenging one that has not been satisfactorily resolved using single modality methods. A more thorough review of PET segmentation algorithms can be found in surveys by Zaidi and El Naqa 26 and Sheperd et al 27 We have adapted an active contour approach due to its ability to define the contour using a continuous function which can intuitively adapt to topological changes such as splitting and merging of multiple regions, as encountered in a heterogenous tumor and to achieve subpixel accuracy.…”

Section: Introductionmentioning

confidence: 99%

Novel multimodality segmentation using level sets and Jensen‐Rényi divergence

2013

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Purpose: Positron emission tomography (PET) is playing an increasing role in radiotherapy treatment planning. However, despite progress, robust algorithms for PET and multimodal image segmentation are still lacking, especially if the algorithm were extended to image-guided and adaptive radiotherapy (IGART). This work presents a novel multimodality segmentation algorithm using the Jensen-Rényi divergence (JRD) to evolve the geometric level set contour. The algorithm offers improved noise tolerance which is particularly applicable to segmentation of regions found in PET and cone-beam computed tomography. Methods: A steepest gradient ascent optimization method is used in conjunction with the JRD and a level set active contour to iteratively evolve a contour to partition an image based on statistical divergence of the intensity histograms. The algorithm is evaluated using PET scans of pharyngolaryngeal squamous cell carcinoma with the corresponding histological reference. The multimodality extension of the algorithm is evaluated using 22 PET/CT scans of patients with lung carcinoma and a physical phantom scanned under varying image quality conditions. Results: The average concordance index (CI) of the JRD segmentation of the PET images was 0.56 with an average classification error of 65%. The segmentation of the lung carcinoma images had a maximum diameter relative error of 63%, 19.5%, and 14.8% when using CT, PET, and combined PET/CT images, respectively. The estimated maximal diameters of the gross tumor volume (GTV) showed a high correlation with the macroscopically determined maximal diameters, with a R 2 value of 0.85 and 0.88 using the PET and PET/CT images, respectively. Results from the physical phantom show that the JRD is more robust to image noise compared to mutual information and region growing. Conclusions:The JRD has shown improved noise tolerance compared to mutual information for the purpose of PET image segmentation. Presented is a flexible framework for multimodal image segmentation that can incorporate a large number of inputs efficiently for IGART.

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Atlas-based Segmentation in Prostate IMRT: Timesavings in the Clinical Workflow

Cited by 13 publications

References 0 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

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

Novel multimodality segmentation using level sets and Jensen‐Rényi divergence

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