Deep‐learning‐based image registration and automatic segmentation of organs‐at‐risk in cone‐beam CT scans from high‐dose radiation treatment of pancreatic cancer

For prostate cancer patients, large organ deformations occurring between radiotherapy treatment sessions create uncertainty about the doses delivered to the tumor and surrounding healthy organs. Segmenting those regions on cone beam CT (CBCT) scans acquired on treatment day would reduce such uncertainties. In this work, a 3D U-net deep-learning architecture was trained to segment bladder, rectum, and prostate on CBCT scans. Due to the scarcity of contoured CBCT scans, the training set was augmented with CT scans already contoured in the current clinical workflow. Our network was then tested on 63 CBCT scans. The Dice similarity coefficient (DSC) increased significantly with the number of CBCT and CT scans in the training set, reaching 0.874 ± 0.096 , 0.814 ± 0.055 , and 0.758 ± 0.101 for bladder, rectum, and prostate, respectively. This was about 10% better than conventional approaches based on deformable image registration between planning CT and treatment CBCT scans, except for prostate. Interestingly, adding 74 CT scans to the CBCT training set allowed maintaining high DSCs, while halving the number of CBCT scans. Hence, our work showed that although CBCT scans included artifacts, cross-domain augmentation of the training set was effective and could rely on large datasets available for planning CT scans.

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Methods of Automatic Assurance of Image Quality in Cone-beam CT Based on Deep Learning

2019 International Conference on Medical Imaging Physics and Engineering (ICMIPE) ◽

10.1109/icmipe47306.2019.9098200 ◽

2019 ◽

Author(s):

Yinping Chan ◽

Xiaokun Liang ◽

Lei Deng ◽

Yaoqin Xie

Keyword(s):

Deep Learning ◽

Image Quality ◽

Cone Beam Ct ◽

Cone Beam

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Improved image quality of cone beam CT scans for radiotherapy image guidance using fiber-interspaced antiscatter grid

Medical Physics ◽

10.1118/1.4875978 ◽

2014 ◽

Vol 41 (6Part1) ◽

pp. 061910 ◽

Cited By ~ 16

Author(s):

Uros Stankovic ◽

Marcel van Herk ◽

Lennert S. Ploeger ◽

Jan-Jakob Sonke

Keyword(s):

Image Quality ◽

Image Guidance ◽

Cone Beam Ct ◽

Ct Scans ◽

Cone Beam ◽

Antiscatter Grid

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EP-1854: Variations of coefficients for estimating effective doses of cone beam CT scans

Radiotherapy and Oncology ◽

10.1016/s0167-8140(18)32163-7 ◽

2018 ◽

Vol 127 ◽

pp. S1000-S1001

Author(s):

A. Abuhaimed ◽

C.J. Martin ◽

O. Demirkaya

Keyword(s):

Cone Beam Ct ◽

Ct Scans ◽

Cone Beam ◽

Effective Doses

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72: Deep Learning-Based Auto-Segmentation for Pelvic Organs-At-Risk and Clinical Target Volumes in Intracavitary High Dose Rate Brachytherapy

Radiotherapy and Oncology ◽

10.1016/s0167-8140(20)30964-6 ◽

2020 ◽

Vol 150 ◽

pp. S34

Author(s):

Jordan Wong ◽

Carter Kolbeck ◽

Jonathan Giambattista ◽

Joshua Giambattista ◽

Vicky Huang ◽

...

Keyword(s):

At Risk ◽

Deep Learning ◽

Dose Rate ◽

Organs At Risk ◽

High Dose Rate ◽

High Dose ◽

High Dose Rate Brachytherapy ◽

Pelvic Organs ◽

Target Volumes ◽

Clinical Target Volumes

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Patient Knowledge Regarding Radiation Exposure from Orthopaedic Foot and Ankle Imaging

Foot & Ankle Orthopaedics ◽

10.1177/2473011418s00158 ◽

2018 ◽

Vol 3 (3) ◽

pp. 2473011418S0015

Author(s):

Daniel Bohl ◽

Blaine Manning ◽

George Holmes ◽

Simon Lee ◽

Johnny Lin ◽

...

Keyword(s):

Ionizing Radiation ◽

Ct Scan ◽

Radiation Exposure ◽

Cone Beam Ct ◽

Plain Film ◽

Ct Scans ◽

Cone Beam ◽

X Rays ◽

Foot And Ankle ◽

X Ray

Category: Other Introduction/Purpose: Foot and ankle surgeons routinely prescribe diagnostic imaging that exposes patients to potentially harmful ionizing radiation. The purpose of this study is to characterize patients’ knowledge regarding radiation exposure associated with common forms of foot and ankle imaging. Methods: A survey was administered to all new patients prior to their first foot and ankle clinic appointments. Patients were asked to compare the amount of harmful radiation associated with chest x-rays to that associated with various types of foot and ankle imaging. Results were tabulated and compared to actual values of radiation exposure from the published literature. Results: A total of 890 patients were invited to participate, of whom 791 (88.9%) completed the survey. The majority of patients believed that a foot x-ray, an ankle x-ray, a “low dose” CT scan of the foot and ankle (alluding to cone-beam CT), and a traditional CT scan of the foot and ankle all contain similar amounts of harmful ionizing radiation to a chest x-ray (Table 1). This is in contrast to the published literature, which suggests that foot x-rays, ankle x-rays, cone beam CT scans of the foot and ankle, and traditional CT scans of the foot and ankle expose patients to 0.006, 0.006, 0.127, and 0.833 chest x-rays worth of radiation. Conclusion: The results of the present study suggest that patients greatly over-estimate the amount of harmful ionizing radiation associated with plain film and cone-beam CT scans of the foot and ankle. Interestingly, their estimates of radiation associated with traditional CT scans of the foot and ankle were relatively accurate. Results suggest that patients may benefit from increased counseling by surgeons regarding the relatively low risk of radiation exposure associated with plain film and cone-beam CT imaging of the foot and ankle.

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Positioning errors of metal localization devices with motion artifacts on kV and MV cone beam CT

BJR|Open ◽

10.1259/bjro.20190013 ◽

2019 ◽

Vol 1 (1) ◽

pp. 20190013

Author(s):

Teh Lin ◽

Chang-Ming Charlie Ma

Keyword(s):

Radiation Treatment ◽

Cone Beam Ct ◽

Motion Artifacts ◽

Cone Beam ◽

Breathing Cycle ◽

Metal Artifacts ◽

Motion Direction ◽

Image Guided Radiation Therapy ◽

Positioning Errors ◽

Image Volume

Objective: To investigate motion artifacts on kV CBCT and MV CBCT images with metal localization devices for image-guided radiation therapy. Methods: The 8 μ pelvis CBCT template for the Siemens Artiste MVision and Pelvis template for the Varian IX on-board Exact Arms kV were used to acquire CBCT images in this study. Images from both CBCT modalities were compared in CNRs, metal landmark absolute positions, and image volume distortion on three different planes of view. The images were taken on a breathing-simulated thoracic phantom in which several typical metal localization devices were implanted, including clips and wires for breast patients, gold seeds for prostate patients, and BBs as skin markers. To magnify the artifacts, a 4 cm diameter metal ball was also implanted into the thoracic phantom to mimic the metal artifacts. Results: For MV CBCT, the CNR at a 4 sec breathing cycle with 1 cm breathing amplitude was 5.0, 3.4 and 4.6 for clips, gold seeds and BBs, respectively while it was 1.5, 2.0 and 1.6 for the kV CBCT. On the images, the kV CBCT showed symmetric streaking artifacts both in the transverse and longitudinal directions relative to the motion direction. The kV CBCT images predicted 89 % of the expected volume, while the MV CBCT images predicted 95 % of the expected volume. The simulated soft tissue observed in the MVCT could not be detected in the kV CBCT. Conclusion: The MV CBCT images showed better volume prediction, less streaking effects and better CNRs of a moving metal target, i.e. clips, BBs, gold seeds and metal balls than on the kV CBCT images. The MV CBCT was more advantageous compared to the kV CBCT with less motion artifacts for metal localization devices. Advances in knowledge: This study would benefit clinicians to prescribe MV CBCT as localization modality for radiation treatment with moving target when metal markers are implanted.

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