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Florea A, Zaric GS, Kang Z, Cool DW. Cost-Effectiveness Analysis Comparing Biopsy in Advance of Ablation versus Concurrent Biopsy and Ablation for Small Renal Masses 1 to 3 cm. J Vasc Interv Radiol 2024:S1051-0443(24)00342-7. [PMID: 38759884 DOI: 10.1016/j.jvir.2024.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 05/01/2024] [Accepted: 05/08/2024] [Indexed: 05/19/2024] Open
Abstract
PURPOSE To analyze the cost-effectiveness of performing a renal mass biopsy in advance of ablation or concurrent with a percutaneous ablation procedure for the management of small renal masses (SRMs). METHODS A decision-analytic model was developed with a cohort of 65-year-old male patients with an incidental, unilateral 1 to 3 cm SRM. A decision tree modeled the first year of clinical intervention, following which patients entered a Markov Model with a lifetime horizon. Patients were assumed to be treated in accordance to established clinical practice guidelines, including surveillance, repeat ablation for recurrence, and systemic therapy for metastasis. Healthcare cost and utility values were determined from published literature or local hospital estimates, discounted at 1.5%. Total lifetime costs were calculated from the perspective of a Canadian health-care payer and converted to 2022 Canadian dollars. The primary outcome was incremental cost effectiveness ratio (ICER), at a willingness-to-pay threshold of $50,000 per quality-adjusted life-years gained. The secondary outcome was ICER at a willingness-to-pay threshold of 50,000 $/LY gained. RESULTS Concurrent biopsy and ablation resulted in a gain of 16.4 quality-adjusted days, at an incremental cost of $386, with an ICER of 8494 $/QALY. The concurrent strategy was the dominant for prevalence of benign mass below 5%. Sequential biopsy and ablation was only cost effective when life-years were not quality-adjusted, and ablation cost was greater than $4300 or benign mass prevalence was greater than 28%. CONCLUSION Concurrent biopsy and ablation is cost-effective relative to pre-treatment diagnostic biopsy for management of incidental small renal masses.
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Affiliation(s)
- Alexandru Florea
- Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
| | - Gregory S Zaric
- Ivey Business School, Western University, London, ON, Canada; Department of Epidemiology and Biostatistics, Western University, London, ON, Canada
| | - Ziru Kang
- Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Derek W Cool
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
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Robert SC, Cossetto T, Miao TL, Li K, Habib E, Mocanu V, Garvin G, Etemad-Rezai R, Cool DW. Complications After Renal Mass Biopsy: Frequency, Nature, Timing, and Associated Characteristics. AJR Am J Roentgenol 2023; 221:344-353. [PMID: 37132549 DOI: 10.2214/ajr.23.29059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
BACKGROUND. Observation periods after renal mass biopsy (RMB) range from 1 hour to overnight hospitalization. Short observation may improve efficiency by allowing use of the same recovery bed and other resources for RMBs in additional patients. OBJECTIVE. The purpose of this study was to evaluate the frequency, timing, and nature of complications after RMB, as well as to identify characteristics associated with such complications. METHODS. This retrospective study included 576 patients (mean age, 64.9 years; 345 men, 231 women) who underwent percutaneous ultrasound- or CT-guided RMB at one of three hospitals, performed by 22 radiologists, between January 1, 2008, and June 1, 2020. The EHR was reviewed to identify postbiopsy complications, which were classified as bleeding-related or non-bleeding-related and as acute (< 24 hours), subacute (24 hours to 30 days), or delayed (> 30 days). Deviations from normal clinical management (analgesia, unplanned laboratory testing, or additional imaging) were identified. RESULTS. Acute and subacute complications occurred after 3.6% (21/576) and 0.7% (4/576) of RMBs, respectively. No delayed complication or patient death occurred. A total of 76.2% (16/21) of acute complications were bleeding-related. A deviation from normal clinical management occurred after 1.6% (9/551) of RMBs that had no associated postbiopsy complication. Among the 16 patients with bleeding-related acute complications, all experienced a deviation, with mean time to deviation of 56 ± 47 (SD) minutes (range, 10-162 minutes; ≤ 120 minutes in 13/16 patients). The five non-bleeding-related acute complications all presented at the time of RMB completion. The four subacute complications occurred from 28 hours to 18 days after RMB. Patients with, versus those without, a bleeding-related complication had a lower platelet count (mean, 197.7 vs 250.4 × 109/L, p = .01) and greater frequency of entirely endophytic renal masses (47.4% vs 19.6%, p = .01). CONCLUSION. Complications after RMB were uncommon and presented either within 3 hours after biopsy or more than 24 hours after biopsy. CLINICAL IMPACT. A 3-hour monitoring window after RMB before patient discharge (in the absence of deviation from normal clinical management and complemented by informing patients of the low risk of a subacute complication) may provide both safe patient management and appropriate resource utilization.
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Affiliation(s)
- Sébastien C Robert
- Department of Medical Imaging, Schulich School of Medicine & Dentistry, Western University London Health Sciences Center, 800 Commissioners Rd E, London, ON N6A 5W9, Canada
| | - Tyler Cossetto
- Department of Medical Imaging, Schulich School of Medicine & Dentistry, Western University London Health Sciences Center, 800 Commissioners Rd E, London, ON N6A 5W9, Canada
| | - Timothy L Miao
- Department of Medical Imaging, Schulich School of Medicine & Dentistry, Western University London Health Sciences Center, 800 Commissioners Rd E, London, ON N6A 5W9, Canada
| | - Katherine Li
- Department of Medical Imaging, McMaster University Medical Centre, Hamilton, ON, Canada
| | - Eric Habib
- Department of Medical Imaging, Schulich School of Medicine & Dentistry, Western University London Health Sciences Center, 800 Commissioners Rd E, London, ON N6A 5W9, Canada
| | - Valentin Mocanu
- Department of Surgery, Division of General Surgery, University of Alberta, Edmonton, AB, Canada
| | - Greg Garvin
- Department of Medical Imaging, St. Joseph's Health Care, London, ON, Canada
| | - Roya Etemad-Rezai
- Department of Medical Imaging, Schulich School of Medicine & Dentistry, Western University London Health Sciences Center, 800 Commissioners Rd E, London, ON N6A 5W9, Canada
| | - Derek W Cool
- Department of Medical Imaging, Schulich School of Medicine & Dentistry, Western University London Health Sciences Center, 800 Commissioners Rd E, London, ON N6A 5W9, Canada
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Xing S, Romero JC, Roy P, Cool DW, Tessier D, Chen ECS, Peters TM, Fenster A. 3D US-CT/MRI registration for percutaneous focal liver tumor ablations. Int J Comput Assist Radiol Surg 2023:10.1007/s11548-023-02915-0. [PMID: 37162735 DOI: 10.1007/s11548-023-02915-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 04/10/2023] [Indexed: 05/11/2023]
Abstract
PURPOSE US-guided percutaneous focal liver tumor ablations have been considered promising curative treatment techniques. To address cases with invisible or poorly visible tumors, registration of 3D US with CT or MRI is a critical step. By taking advantage of deep learning techniques to efficiently detect representative features in both modalities, we aim to develop a 3D US-CT/MRI registration approach for liver tumor ablations. METHODS Facilitated by our nnUNet-based 3D US vessel segmentation approach, we propose a coarse-to-fine 3D US-CT/MRI image registration pipeline based on the liver vessel surface and centerlines. Then, phantom, healthy volunteer and patient studies are performed to demonstrate the effectiveness of our proposed registration approach. RESULTS Our nnUNet-based vessel segmentation model achieved a Dice score of 0.69. In healthy volunteer study, 11 out of 12 3D US-MRI image pairs were successfully registered with an overall centerline distance of 4.03±2.68 mm. Two patient cases achieved target registration errors (TRE) of 4.16 mm and 5.22 mm. CONCLUSION We proposed a coarse-to-fine 3D US-CT/MRI registration pipeline based on nnUNet vessel segmentation models. Experiments based on healthy volunteers and patient trials demonstrated the effectiveness of our registration workflow. Our code and example data are publicly available in this r epository.
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Affiliation(s)
- Shuwei Xing
- Robarts Research Institute, Western University, 100 Perth St., London, ON, N6A 5B7, Canada.
- School of Biomedical Engineering, Western University, 100 Perth St., London, ON, N6A 5B7, Canada.
| | - Joeana Cambranis Romero
- Robarts Research Institute, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
- School of Biomedical Engineering, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
| | - Priyanka Roy
- Robarts Research Institute, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
- Lawson Health Research Institute, 100 Perth St., London, N6A 5B7, ON, Canada
| | - Derek W Cool
- Department of Medical Imaging, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
- Lawson Health Research Institute, 100 Perth St., London, N6A 5B7, ON, Canada
| | - David Tessier
- Robarts Research Institute, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
| | - Elvis C S Chen
- Robarts Research Institute, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
- School of Biomedical Engineering, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
- Department of Medical Biophysics, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
- Department of Medical Imaging, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
- Lawson Health Research Institute, 100 Perth St., London, N6A 5B7, ON, Canada
| | - Terry M Peters
- Robarts Research Institute, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
- School of Biomedical Engineering, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
- Department of Medical Biophysics, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
- Department of Medical Imaging, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
| | - Aaron Fenster
- Robarts Research Institute, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
- School of Biomedical Engineering, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
- Department of Medical Biophysics, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
- Department of Medical Imaging, Western University, 100 Perth St., London, ON, N6A 5B7, Canada
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Xu SS, Eng K, Accorsi F, Cool DW, Wiseman D, Mujoomdar A, Cardarelli-Leite L. Proximal splenic artery embolization using a vascular plug in grade IV or V splenic trauma - a single centre 11-year experience. CVIR Endovasc 2023; 6:1. [PMID: 36627472 PMCID: PMC9832195 DOI: 10.1186/s42155-022-00345-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 12/14/2022] [Indexed: 01/12/2023] Open
Affiliation(s)
- Samuel S. Xu
- grid.39381.300000 0004 1936 8884University of Western Ontario, London, Ontario Canada ,Halton Healthcare Services, 3001 Hospital Gate, Oakville, ON L6M 0L8 Canada
| | - Kevin Eng
- grid.39381.300000 0004 1936 8884University of Western Ontario, London, Ontario Canada
| | - Fabio Accorsi
- grid.39381.300000 0004 1936 8884University of Western Ontario, London, Ontario Canada
| | - Derek W. Cool
- grid.39381.300000 0004 1936 8884University of Western Ontario, London, Ontario Canada
| | - Daniele Wiseman
- grid.39381.300000 0004 1936 8884University of Western Ontario, London, Ontario Canada
| | - Amol Mujoomdar
- grid.39381.300000 0004 1936 8884University of Western Ontario, London, Ontario Canada
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Xing S, Romero JC, Cool DW, Mujoomdar A, Chen ECS, Peters TM, Fenster A. 3D US-Based Evaluation and Optimization of Tumor Coverage for US-Guided Percutaneous Liver Thermal Ablation. IEEE Trans Med Imaging 2022; 41:3344-3356. [PMID: 35724283 DOI: 10.1109/tmi.2022.3184334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Complete tumor coverage by the thermal ablation zone and with a safety margin (5 or 10 mm) is required to achieve the entire tumor eradication in liver tumor ablation procedures. However, 2D ultrasound (US) imaging has limitations in evaluating the tumor coverage by imaging only one or multiple planes, particularly for cases with multiple inserted applicators or irregular tumor shapes. In this paper, we evaluate the intra-procedural tumor coverage using 3D US imaging and investigate whether it can provide clinically needed information. Using data from 14 cases, we employed surface- and volume-based evaluation metrics to provide information on any uncovered tumor region. For cases with incomplete tumor coverage or uneven ablation margin distribution, we also proposed a novel margin uniformity -based approach to provide quantitative applicator adjustment information for optimization of tumor coverage. Both the surface- and volume-based metrics showed that 5 of 14 cases had incomplete tumor coverage according to the estimated ablation zone. After applying our proposed applicator adjustment approach, the simulated results showed that 92.9% (13 of 14) cases achieved 100% tumor coverage and the remaining case can benefit by increasing the ablation time or power. Our proposed method can evaluate the intra-procedural tumor coverage and intuitively provide applicator adjustment information for the physician. Our 3D US-based method is compatible with the constraints of conventional US-guided ablation procedures and can be easily integrated into the clinical workflow.
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Chang SD, Reinhold C, Kirkpatrick IDC, Clarke SE, Schieda N, Hurrell C, Cool DW, Tunis AS, Alabousi A, Diederichs BJ, Haider MA. Canadian Association of Radiologists Prostate MRI White Paper. Can Assoc Radiol J 2022; 73:626-638. [PMID: 35971326 DOI: 10.1177/08465371221105532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Prostate cancer is the most common malignancy and the third most common cause of death in Canadian men. In light of evolving diagnostic pathways for prostate cancer and the increased use of MRI, which now includes its use in men prior to biopsy, the Canadian Association of Radiologists established a Prostate MRI Working Group to produce a white paper to provide recommendations on establishing and maintaining a Prostate MRI Programme in the context of the Canadian healthcare system. The recommendations, which are based on available scientific evidence and/or expert consensus, are intended to maintain quality in image acquisition, interpretation, reporting and targeted biopsy to ensure optimal patient care. The paper covers technique, reporting, quality assurance and targeted biopsy considerations and includes appendices detailing suggested reporting templates, quality assessment tools and sample image acquisition protocols relevant to the Canadian healthcare context.
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Affiliation(s)
- Silvia D Chang
- Department of Radiology, University of British Columbia, Vancouver General Hospital, Vancouver, BC, Canada
| | - Caroline Reinhold
- Augmented Intelligence & Precision Health Laboratory (AIPHL), Department of Radiology and the Research Institute of McGill University Health Centre, McGill University Health Centre, Montreal, QC, Canada
| | | | | | - Nicola Schieda
- Department of Diagnostic Imaging, The Ottawa Hospital- Civic Campus, Ottawa, ON, Canada
| | - Casey Hurrell
- Canadian Association of Radiologists, Ottawa, ON, Canada
| | - Derek W Cool
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Adam S Tunis
- Department of Medical Imaging, University of Toronto, North York General Hospital, Toronto, ON, Canada
| | - Abdullah Alabousi
- Department of Radiology, McMaster University, St. Joseph's Healthcare, Hamilton, ON, Canada
| | | | - Masoom A Haider
- Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada
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7
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Orlando N, Gyacskov I, Gillies DJ, Guo F, Romagnoli C, D'Souza D, Cool DW, Hoover DA, Fenster A. Effect of dataset size, image quality, and image type on deep learning-based automatic prostate segmentation in 3D ultrasound. Phys Med Biol 2022; 67. [PMID: 35240585 DOI: 10.1088/1361-6560/ac5a93] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 03/03/2022] [Indexed: 11/12/2022]
Abstract
Three-dimensional (3D) transrectal ultrasound (TRUS) is utilized in prostate cancer diagnosis and treatment, necessitating time-consuming manual prostate segmentation. We have previously developed an automatic 3D prostate segmentation algorithm involving deep learning prediction on radially sampled 2D images followed by 3D reconstruction, trained on a large, clinically diverse dataset with variable image quality. As large clinical datasets are rare, widespread adoption of automatic segmentation could be facilitated with efficient 2D-based approaches and the development of an image quality grading method. The complete training dataset of 6761 2D images, resliced from 206 3D TRUS volumes acquired using end-fire and side-fire acquisition methods, was split to train two separate networks using either end-fire or side-fire images. Split datasets were reduced to 1000, 500, 250, and 100 2D images. For deep learning prediction, modified U-Net and U-Net++ architectures were implemented and compared using an unseen test dataset of 40 3D TRUS volumes. A 3D TRUS image quality grading scale with three factors (acquisition quality, artifact severity, and boundary visibility) was developed to assess the impact on segmentation performance. For the complete training dataset, U-Net and U-Net++ networks demonstrated equivalent performance, but when trained using split end-fire/side-fire datasets, U-Net++ significantly outperformed the U-Net. Compared to the complete training datasets, U-Net++ trained using reduced-size end-fire and side-fire datasets demonstrated equivalent performance down to 500 training images. For this dataset, image quality had no impact on segmentation performance for end-fire images but did have a significant effect for side-fire images, with boundary visibility having the largest impact. Our algorithm provided fast (<1.5 s) and accurate 3D segmentations across clinically diverse images, demonstrating generalizability and efficiency when employed on smaller datasets, supporting the potential for widespread use, even when data is scarce. The development of an image quality grading scale provides a quantitative tool for assessing segmentation performance.
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Affiliation(s)
- Nathan Orlando
- Department of Medical Biophysics, Western University, London, Ontario N6A 3K7, Canada.,Robarts Research Institute, Western University, London, Ontario N6A 3K7, Canada
| | - Igor Gyacskov
- Robarts Research Institute, Western University, London, Ontario N6A 3K7, Canada
| | - Derek J Gillies
- London Health Sciences Centre, London, Ontario N6A 5W9, Canada
| | - Fumin Guo
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario M4N 3M5, Canada
| | - Cesare Romagnoli
- London Health Sciences Centre, London, Ontario N6A 5W9, Canada.,Department of Medical Imaging, Western University, London, Ontario N6A 3K7, Canada
| | - David D'Souza
- London Health Sciences Centre, London, Ontario N6A 5W9, Canada.,Department of Oncology, Western University, London, Ontario N6A 3K7, Canada
| | - Derek W Cool
- London Health Sciences Centre, London, Ontario N6A 5W9, Canada.,Department of Medical Imaging, Western University, London, Ontario N6A 3K7, Canada
| | - Douglas A Hoover
- Department of Medical Biophysics, Western University, London, Ontario N6A 3K7, Canada.,London Health Sciences Centre, London, Ontario N6A 5W9, Canada.,Department of Oncology, Western University, London, Ontario N6A 3K7, Canada
| | - Aaron Fenster
- Department of Medical Biophysics, Western University, London, Ontario N6A 3K7, Canada.,Robarts Research Institute, Western University, London, Ontario N6A 3K7, Canada.,Department of Medical Imaging, Western University, London, Ontario N6A 3K7, Canada.,Department of Oncology, Western University, London, Ontario N6A 3K7, Canada
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Accorsi F, Chung J, Mujoomdar A, Wiseman D, Kribs S, Cool DW. Percutaneous ultrasound gastrostomy (PUG): first prospective clinical trial. Abdom Radiol (NY) 2021; 46:5377-5385. [PMID: 34240242 PMCID: PMC8502161 DOI: 10.1007/s00261-021-03200-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 06/26/2021] [Accepted: 06/28/2021] [Indexed: 12/30/2022]
Abstract
GRAPHICAL ABSTARCT PURPOSE: To report the results of the first-in-human trial evaluating the safety and efficacy of the percutaneous ultrasound gastrostomy (PUG) technique. METHODS A prospective, industry-sponsored single-arm clinical trial of PUG insertion was performed in 25 adult patients under investigational device exemption (mean age 64 ± 15 years, 92% men, 80% inpatients, mean BMI 24.5 ± 2.7 kg/m2). A propensity score-matched retrospective cohort of 25 patients who received percutaneous radiologic gastrostomy (PRG) was generated as an institutional control (mean age 66 ± 14 years, 92% men, 80% inpatients, mean BMI 24.0 ± 2.7 kg/m2). Primary outcomes included successful insertion and 30-day procedure-related adverse events (AE's). Secondary outcomes included procedural duration, sedation requirements, and hospital length of stay. RESULTS All PUG procedures were successful, including 3/25 [12%] performed bedside within the ICU. There was no significant difference between PUG and PRG in rates of mild AE's (3/25 [12%] for PUG and 7/25 [28%] for PRG, p = 0.16) or moderate AE's (1/25 [4%] for PUG and 0/25 for PRG, p = 0.31). There were no severe AE's or 30-day procedure-related mortality in either group. Procedural room time was longer for PUG (56.5 ± 14.1 min) than PRG (39.3 ± 15.0 min, p < 0.001). PUG procedure time was significantly shorter after a procedural enhancement, the incorporation of a Gauss meter to facilitate successful magnetic gastropexy. Length of stay for outpatients did not significantly differ (2.4 ± 0.5 days for PUG and 2.6 ± 1.0 days for PRG, p = 0.70). CONCLUSION PUG appears effective with a safety profile similar to PRG. Bedside point-of-care gastrostomy tube insertion using the PUG technique shows promise. TRIAL REGISTRATION NUMBER ClinicalTrials.gov ID NCT03575754.
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Affiliation(s)
- Fabio Accorsi
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Jonathan Chung
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Amol Mujoomdar
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Daniele Wiseman
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Stewart Kribs
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Derek W Cool
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
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Smith CW, Hoover D, Surry K, D'Souza D, Cool DW, Kassam Z, Bastian-Jordan M, Gomez JA, Moussa M, Chin J, Pautler S, Bauman GS, Ward AD. A multiobserver study investigating the effectiveness of prostatic multiparametric magnetic resonance imaging to dose escalate corresponding histologic lesions using high-dose-rate brachytherapy. Brachytherapy 2021; 20:601-610. [PMID: 33648893 DOI: 10.1016/j.brachy.2021.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/14/2021] [Accepted: 01/22/2021] [Indexed: 12/29/2022]
Abstract
PURPOSE Using multiparametric MRI data and the pathologic data from radical prostatectomy specimens, we simulated the treatment planning of dose-escalated high-dose-rate brachytherapy (HDR-BT) to the Multiparametric MRI dominant intraprostatic lesion (mpMRI-DIL) to compare the dose potentially delivered to the pathologically confirmed locations of the high-grade component of the cancer. METHODS AND MATERIALS Pathologist-annotated prostatectomy midgland histology sections from 12 patients were registered to preprostatectomy mpMRI scans that were interpreted by four radiologists. To simulate realistic HDR-BT, we registered each observer's mpMRI-DILs and corresponding histology to two transrectal ultrasound images of other HDR-BT patients with a 15-Gy whole-gland prescription. We used clinical inverse planning to escalate the mpMRI-DILs to 20.25 Gy. We compared the dose that the histopathology would have received if treated with standard treatment plans to the dose mpMRI-targeting would have achieved. The histopathology was grouped as high-grade cancer (any Gleason Grade 4 or 5) and low-grade cancer (only Gleason Grade 3). RESULTS 212 mpMRI-targeted HDR-BT plans were analyzed. For high-grade histology, the mpMRI-targeted plans achieved significantly higher median [IQR] D98 and D90 values of 18.2 [16.7-19.5] Gy and 19.4 [17.8-20.9] Gy, respectively, in comparison with the standard plans (p = 0.01 and p = 0.003). For low-grade histology, the targeted treatment plans would have resulted in a significantly higher median D90 of 17.0 [16.1-18.4] Gy in comparison with standard plans (p = 0.015); the median D98 was not significantly higher (p = 0.2). CONCLUSIONS In this retrospective pilot study of 12 patients, mpMRI-based dose escalation led to increased dose to high-grade, but not low-grade, cancer. In our data set, different observers and mpMRI sequences had no substantial effect on dose to histologic cancer.
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Affiliation(s)
- Christopher W Smith
- Baines Imaging Research Laboratory, London, Ontario, Canada; Lawson Health Research Institute, London, Ontario, Canada; Department of Medical Biophysics, Western University, London, Ontario, Canada; London Regional Cancer Program, London, Ontario, Canada
| | - Douglas Hoover
- Lawson Health Research Institute, London, Ontario, Canada; Department of Medical Biophysics, Western University, London, Ontario, Canada; London Regional Cancer Program, London, Ontario, Canada
| | - Kathleen Surry
- Lawson Health Research Institute, London, Ontario, Canada; Department of Medical Biophysics, Western University, London, Ontario, Canada; London Regional Cancer Program, London, Ontario, Canada
| | - David D'Souza
- Lawson Health Research Institute, London, Ontario, Canada; Department of Oncology, Western University, London, Ontario, Canada; London Regional Cancer Program, London, Ontario, Canada
| | - Derek W Cool
- Lawson Health Research Institute, London, Ontario, Canada; Department of Medical Imaging, Western University, London, Ontario, Canada
| | - Zahra Kassam
- Lawson Health Research Institute, London, Ontario, Canada; Department of Medical Imaging, Western University, London, Ontario, Canada
| | - Matthew Bastian-Jordan
- Department of Medical Imaging, University of Queensland, Brisbane, Queensland, Australia
| | - Jose A Gomez
- Department of Pathology and Laboratory Medicine, Western University, London, Ontario, Canada
| | - Madeleine Moussa
- Department of Pathology and Laboratory Medicine, Western University, London, Ontario, Canada
| | - Joseph Chin
- Department of Surgery, Western University, London, Ontario, Canada; Department of Oncology, Western University, London, Ontario, Canada
| | - Stephen Pautler
- Department of Surgery, Western University, London, Ontario, Canada; Department of Oncology, Western University, London, Ontario, Canada
| | - Glenn S Bauman
- Department of Medical Biophysics, Western University, London, Ontario, Canada; Department of Oncology, Western University, London, Ontario, Canada; London Regional Cancer Program, London, Ontario, Canada
| | - Aaron D Ward
- Baines Imaging Research Laboratory, London, Ontario, Canada; Lawson Health Research Institute, London, Ontario, Canada; Department of Medical Biophysics, Western University, London, Ontario, Canada; Department of Oncology, Western University, London, Ontario, Canada; London Regional Cancer Program, London, Ontario, Canada.
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10
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Cool DW, Xu SS, Li KJ, Power NE, Kribs SW. Percutaneous Neoanastomosis Creation for an Ileal Conduit Ureteroenteric Occlusion using Radiofrequency Guidewire and Snare Target Technique. J Vasc Interv Radiol 2021; 32:778-781. [PMID: 33640218 DOI: 10.1016/j.jvir.2020.12.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/06/2020] [Accepted: 12/08/2020] [Indexed: 10/22/2022] Open
Affiliation(s)
- Derek W Cool
- Division of Interventional Radiology, Department of Medical Imaging, Western University, 800 Commissioners Rd E, London, ON N6A 5W9, Canada
| | - Samuel S Xu
- Division of Interventional Radiology, Department of Medical Imaging, Western University, 800 Commissioners Rd E, London, ON N6A 5W9, Canada
| | - Katherine J Li
- Division of Interventional Radiology, Department of Medical Imaging, Western University, 800 Commissioners Rd E, London, ON N6A 5W9, Canada
| | - Nicholas E Power
- Division of Urology, Department of Surgery, Western University, 800 Commissioners Rd E, London, ON N6A 5W9, Canada
| | - Stewart W Kribs
- Division of Interventional Radiology, Department of Medical Imaging, Western University, 800 Commissioners Rd E, London, ON N6A 5W9, Canada
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11
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Li KJ, Leslie K, Cool DW. Successful percutaneous transgastric diversion of a chronic post-operative combined pancreaticocutaneous and gastrocutaneous fistula using a snare-target technique: A case report. Int J Surg Case Rep 2021; 80:105685. [PMID: 33667911 PMCID: PMC7933736 DOI: 10.1016/j.ijscr.2021.105685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 11/29/2022] Open
Abstract
Complicated pancreatico-gastrocutaneous fistulae are rare and require drainage. Conventional treatments may be limited by small fistula tract size and visibility. Percutaneous snare-target transgastric approach for drainage is a good alternative.
Introduction Gastrocutaneous fistula complicating a post-operative or post-pancreatitis pancreatic fistula is uncommon, but has a high mortality rate and typically occurs 6–9 weeks after initial drainage. Conventional methods of treatment may be limited by the size of the fistula tract and visibility. Presentation of case A 57-year-old man presented with a pancreatic duct leak, ten days after undergoing a distal pancreatectomy for renal cell carcinoma metastasis. Initial drainage attempts resulted in a chronic pancreaticocutaneous fistula (PCF)1 complicated by a separate gastric fistula sharing the same cutaneous tract along the inserted drain as well as recurrent symptomatic pleural effusions requiring repeat hospitalizations for management. The chronic fistula tract was too small for conventional direct puncture under fluoroscopic or endoscopic ultrasound guidance; therefore, percutaneous transgastric diversion of the combined pancreatico-gastrocutaneous fistula using a snare-target approach was performed with complete resolution of clinical symptoms. Discussion Complicated pancreatico-gastrocutaneous fistulae are rare and typically require drainage, either surgically or via percutaneous direct transgastric puncture or endoscopic-ultrasound guided stent insertion. This case report demonstrates that a minimally-invasive percutaneous snare-target approach can be effective in treating complex fistulae too small to be accessed through these conventional methods. This case also demonstrates that transgastric drainage along the tract, remote from either organ’s fistula origin, can successfully divert and resolve the complex fistula without requiring direct drainage of the pancreatic duct itself. Conclusion Incorporating the snare-target technique facilitates accurate transgastric drain placement within chronic fistula, particularly when the fistula caliber is too small for conventional drainage methods.
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Affiliation(s)
- Katherine J Li
- Division of Interventional Radiology, Department of Medical Imaging, Western University, 800 Commissioners Rd E, London, ON, N6A 5W9, Canada.
| | - Ken Leslie
- Division of General Surgery, Department of Surgery, Western University, 800 Commissioners Rd E, London, ON, N6A 5W9, Canada
| | - Derek W Cool
- Division of Interventional Radiology, Department of Medical Imaging, Western University, 800 Commissioners Rd E, London, ON, N6A 5W9, Canada
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12
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Xu SS, Hocking D, Cool DW, Wiseman D, Mujoomdar A. Nonmalignant Enhancement Following Percutaneous Renal Ablation Mimicking Viable Malignancy. Cardiovasc Intervent Radiol 2020; 44:176-178. [PMID: 33000318 DOI: 10.1007/s00270-020-02639-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 08/27/2020] [Indexed: 10/23/2022]
Affiliation(s)
- Samuel S Xu
- Department of Medical Imaging, Western University, London Health Sciences, London, ON, Canada.
| | - David Hocking
- Division of Interventional Radiology, Department of Medical Imaging, Western University, London Health Sciences, London, ON, Canada
| | - Derek W Cool
- Division of Interventional Radiology, Department of Medical Imaging, Western University, London Health Sciences, London, ON, Canada
| | - Daniele Wiseman
- Division of Interventional Radiology, Department of Medical Imaging, Western University, London Health Sciences, London, ON, Canada
| | - Amol Mujoomdar
- Division of Interventional Radiology, Department of Medical Imaging, Western University, London Health Sciences, London, ON, Canada
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13
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Gillies DJ, Rodgers JR, Gyacskov I, Roy P, Kakani N, Cool DW, Fenster A. Deep learning segmentation of general interventional tools in two‐dimensional ultrasound images. Med Phys 2020; 47:4956-4970. [DOI: 10.1002/mp.14427] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/05/2020] [Accepted: 07/21/2020] [Indexed: 12/18/2022] Open
Affiliation(s)
- Derek J. Gillies
- Department of Medical Biophysics Western University London OntarioN6A 3K7 Canada
- Robarts Research Institute Western University London OntarioN6A 3K7 Canada
| | - Jessica R. Rodgers
- Robarts Research Institute Western University London OntarioN6A 3K7 Canada
- School of Biomedical Engineering Western University London OntarioN6A 3K7 Canada
| | - Igor Gyacskov
- Robarts Research Institute Western University London OntarioN6A 3K7 Canada
| | - Priyanka Roy
- Department of Medical Biophysics Western University London OntarioN6A 3K7 Canada
- Robarts Research Institute Western University London OntarioN6A 3K7 Canada
| | - Nirmal Kakani
- Department of Radiology Manchester Royal Infirmary ManchesterM13 9WL UK
| | - Derek W. Cool
- Department of Medical Imaging Western University London OntarioN6A 3K7 Canada
| | - Aaron Fenster
- Department of Medical Biophysics Western University London OntarioN6A 3K7 Canada
- Robarts Research Institute Western University London OntarioN6A 3K7 Canada
- School of Biomedical Engineering Western University London OntarioN6A 3K7 Canada
- Department of Medical Imaging Western University London OntarioN6A 3K7 Canada
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14
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Gillies DJ, Awad J, Rodgers JR, Edirisinghe C, Cool DW, Kakani N, Fenster A. Three-dimensional therapy needle applicator segmentation for ultrasound-guided focal liver ablation. Med Phys 2019; 46:2646-2658. [PMID: 30994191 DOI: 10.1002/mp.13548] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 03/06/2019] [Accepted: 03/28/2019] [Indexed: 12/19/2022] Open
Abstract
PURPOSE Minimally invasive procedures, such as microwave ablation, are becoming first-line treatment options for early-stage liver cancer due to lower complication rates and shorter recovery times than conventional surgical techniques. Although these procedures are promising, one reason preventing widespread adoption is inadequate local tumor ablation leading to observations of higher local cancer recurrence compared to conventional procedures. Poor ablation coverage has been associated with two-dimensional (2D) ultrasound (US) guidance of the therapy needle applicators and has stimulated investigation into the use of three-dimensional (3D) US imaging for these procedures. We have developed a supervised 3D US needle applicator segmentation algorithm using a single user input to augment the addition of 3D US to the current focal liver tumor ablation workflow with the goals of identifying and improving needle applicator localization efficiency. METHODS The algorithm is initialized by creating a spherical search space of line segments around a manually chosen seed point that is selected by a user on the needle applicator visualized in a 3D US image. The most probable trajectory is chosen by maximizing the count and intensity of threshold voxels along a line segment and is filtered using the Otsu method to determine the tip location. Homogeneous tissue mimicking phantom images containing needle applicators were used to optimize the parameters of the algorithm prior to a four-user investigation on retrospective 3D US images of patients who underwent microwave ablation for liver cancer. Trajectory, axis localization, and tip errors were computed based on comparisons to manual segmentations in 3D US images. RESULTS Segmentation of needle applicators in ten phantom 3D US images was optimized to median (Q1, Q3) trajectory, axis, and tip errors of 2.1 (1.1, 3.6)°, 1.3 (0.8, 2.1) mm, and 1.3 (0.7, 2.5) mm, respectively, with a mean ± SD segmentation computation time of 0.246 ± 0.007 s. Use of the segmentation method with a 16 in vivo 3D US patient dataset resulted in median (Q1, Q3) trajectory, axis, and tip errors of 4.5 (2.4, 5.2)°, 1.9 (1.7, 2.1) mm, and 5.1 (2.2, 5.9) mm based on all users. CONCLUSIONS Segmentation of needle applicators in 3D US images during minimally invasive liver cancer therapeutic procedures could provide a utility that enables enhanced needle applicator guidance, placement verification, and improved clinical workflow. A semi-automated 3D US needle applicator segmentation algorithm used in vivo demonstrated localization of the visualized trajectory and tip with less than 5° and 5.2 mm errors, respectively, in less than 0.31 s. This offers the ability to assess and adjust needle applicator placements intraoperatively to potentially decrease the observed liver cancer recurrence rates associated with current ablation procedures. Although optimized for deep and oblique angle needle applicator insertions, this proposed workflow has the potential to be altered for a variety of image-guided minimally invasive procedures to improve localization and verification of therapy needle applicators intraoperatively.
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Affiliation(s)
- Derek J Gillies
- Department of Medical Biophysics, Western University, London, ON, N6A 3K7, Canada.,Robarts Research Institute, Western University, London, ON, N6A 3K7, Canada
| | - Joseph Awad
- Centre for Imaging Technology Commercialization, London, ON, N6G 4X8, Canada
| | - Jessica R Rodgers
- Robarts Research Institute, Western University, London, ON, N6A 3K7, Canada.,School of Biomedical Engineering, Western University, London, ON, N6A 3K7, Canada
| | | | - Derek W Cool
- Department of Medical Imaging, Western University, London, ON, N6A 3K7, Canada
| | - Nirmal Kakani
- Department of Radiology, Manchester Royal Infirmary, Manchester, M13 9WL, UK
| | - Aaron Fenster
- Department of Medical Biophysics, Western University, London, ON, N6A 3K7, Canada.,Robarts Research Institute, Western University, London, ON, N6A 3K7, Canada.,Centre for Imaging Technology Commercialization, London, ON, N6G 4X8, Canada.,School of Biomedical Engineering, Western University, London, ON, N6A 3K7, Canada.,Department of Medical Imaging, Western University, London, ON, N6A 3K7, Canada
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15
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Lin M, Chen W, Zhao M, Gibson E, Bastian-Jordan M, Cool DW, Kassam Z, Liang H, Chow TW, Ward AD, Chiu B. Prostate lesion delineation from multiparametric magnetic resonance imaging based on locality alignment discriminant analysis. Med Phys 2018; 45:4607-4618. [DOI: 10.1002/mp.13155] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 06/07/2018] [Accepted: 08/17/2018] [Indexed: 11/05/2022] Open
Affiliation(s)
- Mingquan Lin
- Department of Electronic Engineering; City University of Hong Kong; Hong Kong China
| | - Weifu Chen
- School of Mathematics; Sun Yat-sen University; Guangzhou Guangdong China
- Department of Electronic Engineering; City University of Hong Kong; Hong Kong China
| | - Mingbo Zhao
- School of Information Science and Technology; Donghua University; Shanghai China
| | - Eli Gibson
- Biomedical Engineering; University of Western Ontario; London Ontario Canada
- Centre for Medical Image Computing; University College London; London UK
| | | | - Derek W. Cool
- Department of Medical Imaging; University of Western Ontario; London Ontario Canada
| | - Zahra Kassam
- Department of Medical Imaging; University of Western Ontario; London Ontario Canada
- Lawson Health Research Institute; London Ontario Canada
| | - Huageng Liang
- Department of Urology; Union Hospital; Tongji Medical College; Huazhong University of Science and Technology; Wuhan Hubei China
| | - Tommy W.S. Chow
- Department of Electronic Engineering; City University of Hong Kong; Hong Kong China
| | - Aaron D. Ward
- Department of Medical Biophysics; University of Western Ontario; London Ontario Canada
- Lawson Health Research Institute; London Ontario Canada
| | - Bernard Chiu
- Department of Electronic Engineering; City University of Hong Kong; Hong Kong China
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16
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Shahedi M, Cool DW, Bauman GS, Bastian-Jordan M, Fenster A, Ward AD. Accuracy Validation of an Automated Method for Prostate Segmentation in Magnetic Resonance Imaging. J Digit Imaging 2018; 30:782-795. [PMID: 28342043 DOI: 10.1007/s10278-017-9964-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Three dimensional (3D) manual segmentation of the prostate on magnetic resonance imaging (MRI) is a laborious and time-consuming task that is subject to inter-observer variability. In this study, we developed a fully automatic segmentation algorithm for T2-weighted endorectal prostate MRI and evaluated its accuracy within different regions of interest using a set of complementary error metrics. Our dataset contained 42 T2-weighted endorectal MRI from prostate cancer patients. The prostate was manually segmented by one observer on all of the images and by two other observers on a subset of 10 images. The algorithm first coarsely localizes the prostate in the image using a template matching technique. Then, it defines the prostate surface using learned shape and appearance information from a set of training images. To evaluate the algorithm, we assessed the error metric values in the context of measured inter-observer variability and compared performance to that of our previously published semi-automatic approach. The automatic algorithm needed an average execution time of ∼60 s to segment the prostate in 3D. When compared to a single-observer reference standard, the automatic algorithm has an average mean absolute distance of 2.8 mm, Dice similarity coefficient of 82%, recall of 82%, precision of 84%, and volume difference of 0.5 cm3 in the mid-gland. Concordant with other studies, accuracy was highest in the mid-gland and lower in the apex and base. Loss of accuracy with respect to the semi-automatic algorithm was less than the measured inter-observer variability in manual segmentation for the same task.
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Affiliation(s)
- Maysam Shahedi
- Baines Imaging Research Laboratory, London Regional Cancer Program, A3-123A, 790 Commissioners Rd E, London, ON, N6A 4L6, Canada. .,Robarts Research Institute, The University of Western Ontario, London, ON, Canada. .,Graduate Program in Biomedical Engineering, The University of Western Ontario, London, ON, Canada.
| | - Derek W Cool
- Robarts Research Institute, The University of Western Ontario, London, ON, Canada.,The Department of Medical Imaging, The University of Western Ontario, London, ON, Canada
| | - Glenn S Bauman
- Baines Imaging Research Laboratory, London Regional Cancer Program, A3-123A, 790 Commissioners Rd E, London, ON, N6A 4L6, Canada.,The Department of Medical Biophysics, The University of Western Ontario, London, ON, Canada.,The Department of Oncology, The University of Western Ontario, London, ON, Canada
| | - Matthew Bastian-Jordan
- The Department of Medical Imaging, The University of Western Ontario, London, ON, Canada
| | - Aaron Fenster
- Robarts Research Institute, The University of Western Ontario, London, ON, Canada.,Graduate Program in Biomedical Engineering, The University of Western Ontario, London, ON, Canada.,The Department of Medical Imaging, The University of Western Ontario, London, ON, Canada.,The Department of Medical Biophysics, The University of Western Ontario, London, ON, Canada
| | - Aaron D Ward
- Baines Imaging Research Laboratory, London Regional Cancer Program, A3-123A, 790 Commissioners Rd E, London, ON, N6A 4L6, Canada.,Graduate Program in Biomedical Engineering, The University of Western Ontario, London, ON, Canada.,The Department of Medical Biophysics, The University of Western Ontario, London, ON, Canada.,The Department of Oncology, The University of Western Ontario, London, ON, Canada
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17
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Chen W, Lin M, Gibson E, Bastian-Jordan M, Cool DW, Kassam Z, Liang H, Feng G, Ward AD, Chiu B. A self-tuned graph-based framework for localization and grading prostate cancer lesions: An initial evaluation based on multiparametric magnetic resonance imaging. Comput Biol Med 2018; 96:252-265. [DOI: 10.1016/j.compbiomed.2018.03.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 03/29/2018] [Accepted: 03/29/2018] [Indexed: 11/26/2022]
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18
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Martin PR, Cool DW, Fenster A, Ward AD. A comparison of prostate tumor targeting strategies using magnetic resonance imaging-targeted, transrectal ultrasound-guided fusion biopsy. Med Phys 2018; 45:1018-1028. [PMID: 29363762 DOI: 10.1002/mp.12769] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 12/10/2017] [Accepted: 12/29/2017] [Indexed: 12/29/2022] Open
Abstract
PURPOSE Magnetic resonance imaging (MRI)-targeted, three-dimensional (3D) transrectal ultrasound (TRUS)-guided prostate biopsy aims to reduce the 21-47% false-negative rate of clinical two-dimensional (2D) TRUS-guided systematic biopsy, but continues to yield false-negative results. This may be improved via needle target optimization, accounting for guidance system errors and image registration errors. As an initial step toward the goal of optimized prostate biopsy targeting, we investigated how needle delivery error impacts tumor sampling probability for two targeting strategies. METHODS We obtained MRI and 3D TRUS images from 49 patients. A radiologist and radiology resident assessed these MR images and contoured 81 suspicious regions, yielding tumor surfaces that were registered to 3D TRUS. The biopsy system's root-mean-squared needle delivery error (RMSE) and systematic error were modeled using an isotropic 3D Gaussian distribution. We investigated two different prostate tumor-targeting strategies using (a) the tumor's centroid and (b) a ring in the lateral-elevational plane. For each simulation, targets were spaced at equal arc lengths on a ring with radius equal to the systematic error magnitude. A total of 1000 biopsy simulations were conducted for each tumor, with RMSE and systematic error magnitudes ranging from 1 to 6 mm. The difference in median tumor sampling probability and probability of obtaining a 50% core involvement was determined for ring vs centroid targeting. RESULTS Our simulation results indicate that ring targeting outperformed centroid targeting in situations where systematic error exceeds RMSE. In these instances, we observed statistically significant differences showing 1-32% improvement in sampling probability due to ring targeting. Likewise, we observed statistically significant differences showing 1-39% improvement in 50% core involvement probability due to ring targeting. CONCLUSIONS Our results suggest that the optimal targeting scheme for prostate biopsy depends on the relative levels of systematic and random errors in the system. Where systematic error dominates, a ring-targeting scheme may yield improved probability of tumor sampling. The findings presented in this paper may be used to aid in target selection strategies for clinicians performing targeted prostate biopsies on any MRI targeted, 3D TRUS-guided biopsy system and could support earlier diagnosis of prostate cancer while it remains localized to the gland and curable.
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Affiliation(s)
- Peter R Martin
- Department of Medical Biophysics, The University of Western Ontario, London, Canada, N6A 3K7
| | - Derek W Cool
- Department of Medical Imaging, The University of Western Ontario, London, Canada, N6A 3K7
| | - Aaron Fenster
- Department of Medical Biophysics, The University of Western Ontario, London, Canada, N6A 3K7.,Department of Medical Imaging, The University of Western Ontario, London, Canada, N6A 3K7.,Robarts Research Institute, The University of Western Ontario, London, Canada, N6A 3K7
| | - Aaron D Ward
- Department of Medical Biophysics, The University of Western Ontario, London, Canada, N6A 3K7.,Department of Oncology, The University of Western Ontario, London, Canada, N6A 3K7
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19
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De Silva T, Cool DW, Yuan J, Romagnoli C, Samarabandu J, Fenster A, Ward AD. Robust 2-D-3-D Registration Optimization for Motion Compensation During 3-D TRUS-Guided Biopsy Using Learned Prostate Motion Data. IEEE Trans Med Imaging 2017; 36:2010-2020. [PMID: 28499993 DOI: 10.1109/tmi.2017.2703150] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
In magnetic resonance (MR)-targeted, 3-D transrectal ultrasound (TRUS)-guided biopsy, prostate motion during the procedure increases the needle targeting error and limits the ability to accurately sample MR-suspicious tumor volumes. The robustness of the 2-D-3-D registration methods for prostate motion compensation is impacted by local optima in the search space. In this paper, we analyzed the prostate motion characteristics and investigated methods to incorporate such knowledge into the registration optimization framework to improve robustness against local optima. Rigid motion of the prostate was analyzed adopting a mixture-of-Gaussian (MoG) model using 3-D TRUS images acquired at bilateral sextant probe positions with a mechanically assisted biopsy system. The learned motion characteristics were incorporated into Powell's direction set method by devising multiple initial search positions and initial search directions. Experiments were performed on data sets acquired during clinical biopsy procedures, and registration error was evaluated using target registration error (TRE) and converged image similarity metric values after optimization. After incorporating the learned initialization positions and directions in Powell's method, 2-D-3-D registration to compensate for motion during prostate biopsy was performed with rms ± std TRE of 2.33 ± 1.09 mm with ~3 s mean execution time per registration. This was an improvement over 3.12 ± 1.70 mm observed in Powell's standard approach. For the data acquired under clinical protocols, the converged image similarity metric value improved in ≥8% of the registrations whereas it degraded only ≤1% of the registrations. The reported improvements in optimization indicate useful advancements in robustness to ensure smooth clinical integration of a registration solution for motion compensation that facilitates accurate sampling of the smallest clinically significant tumors.
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20
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Cool DW, Kachura JR. Radiofrequency Ablation of T1a Renal Cell Carcinomas within Renal Transplant Allografts: Oncologic Outcomes and Graft Viability. J Vasc Interv Radiol 2017; 28:1658-1663. [PMID: 28916346 DOI: 10.1016/j.jvir.2017.07.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 07/17/2017] [Accepted: 07/23/2017] [Indexed: 02/09/2023] Open
Abstract
PURPOSE To evaluate oncologic outcomes and graft viability after percutaneous radiofrequency (RF) ablation of renal cell carcinoma (RCC) developing within renal transplant allografts. MATERIALS AND METHODS A single-institution, retrospective study reviewed all patients treated with RF ablation for RCC between February 2004 and May 2016. Ten patients were identified (age 49.6 y ± 12.6; 9 men, 1 woman) with 12 biopsy-confirmed RCC tumors within the allograft (all T1a, mean diameter 2.0 cm ± 0.7). Mean time from transplant to RCC diagnosis was 13.2 years ± 6.3. RF ablation was performed on an outpatient basis using conscious sedation. Procedural efficacy, complications, oncologic outcomes, and allograft function were evaluated. Statistical analysis with t tests and Pearson correlation compared allograft function before and after RF ablation and impact of proportional ablation size to allograft volume on function after ablation. RESULTS Technical success rate and primary technique efficacy were 100% (12/12). No local or distant RCC progression was seen at mean follow-up of 54.3 months ± 38.7 (range, 9-136 months). Graft failure requiring hemodialysis or repeat transplantation occurred in 3 patients (26, 354, and 750 d after RF ablation), all of whom had glomerular filtration rate (GFR) < 30 mL/min/1.73 m2 before ablation. For all patients, mean GFR 6 months after RF ablation (35.8 mL/min/1.73 m2 ± 17.7) was not significantly different (P = .8) from preprocedure GFR (36.2 mL/min/1.73 m2 ± 14.3). Proportional volume of allograft that was ablated did not correlate with immediate or long-term GFR changes. One patient died of unrelated comorbidities 52 months after ablation. No major complications occurred. CONCLUSIONS RF ablation of renal allograft RCC provided effective oncologic control without adverse impact on graft viability.
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Affiliation(s)
- Derek W Cool
- Division of Vascular and Interventional Radiology, Department of Medical Imaging, University of Toronto, University Health Network, 200 Elizabeth St., Toronto, M5G 2C4, Canada.
| | - John R Kachura
- Division of Vascular and Interventional Radiology, Department of Medical Imaging, University of Toronto, University Health Network, 200 Elizabeth St., Toronto, M5G 2C4, Canada
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21
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Shahedi M, Cool DW, Romagnoli C, Bauman GS, Bastian-Jordan M, Rodrigues G, Ahmad B, Lock M, Fenster A, Ward AD. Postediting prostate magnetic resonance imaging segmentation consistency and operator time using manual and computer-assisted segmentation: multiobserver study. J Med Imaging (Bellingham) 2016; 3:046002. [PMID: 27872873 DOI: 10.1117/1.jmi.3.4.046002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 09/19/2016] [Indexed: 11/14/2022] Open
Abstract
Prostate segmentation on T2w MRI is important for several diagnostic and therapeutic procedures for prostate cancer. Manual segmentation is time-consuming, labor-intensive, and subject to high interobserver variability. This study investigated the suitability of computer-assisted segmentation algorithms for clinical translation, based on measurements of interoperator variability and measurements of the editing time required to yield clinically acceptable segmentations. A multioperator pilot study was performed under three pre- and postediting conditions: manual, semiautomatic, and automatic segmentation. We recorded the required editing time for each segmentation and measured the editing magnitude based on five different spatial metrics. We recorded average editing times of 213, 328, and 393 s for manual, semiautomatic, and automatic segmentation respectively, while an average fully manual segmentation time of 564 s was recorded. The reduced measured postediting interoperator variability of semiautomatic and automatic segmentations compared to the manual approach indicates the potential of computer-assisted segmentation for generating a clinically acceptable segmentation faster with higher consistency. The lack of strong correlation between editing time and the values of typically used error metrics ([Formula: see text]) implies that the necessary postsegmentation editing time needs to be measured directly in order to evaluate an algorithm's suitability for clinical translation.
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Affiliation(s)
- Maysam Shahedi
- London Regional Cancer Program, 790 Commissioners Road, London, Ontario N6A 4L6, Canada; University of Western Ontario, Robarts Research Institute, 1151 Richmond Street, London, Ontario N6A 5B7, Canada; University of Western Ontario, Graduate Program in Biomedical Engineering, 1151 Richmond Street, London, Ontario N6A 3K7, Canada
| | - Derek W Cool
- University of Western Ontario, Robarts Research Institute, 1151 Richmond Street, London, Ontario N6A 5B7, Canada; University of Western Ontario, Department of Medical Imaging, 1151 Richmond Street, London, Ontario N6A 3K7, Canada
| | - Cesare Romagnoli
- University of Western Ontario , Department of Medical Imaging, 1151 Richmond Street, London, Ontario N6A 3K7, Canada
| | - Glenn S Bauman
- London Regional Cancer Program, 790 Commissioners Road, London, Ontario N6A 4L6, Canada; University of Western Ontario, Department of Medical Biophysics, 1151 Richmond Street, London, Ontario N6A 3K7, Canada; University of Western Ontario, Department of Oncology, 1151 Richmond Street, London, Ontario N6A 3K7, Canada
| | - Matthew Bastian-Jordan
- University of Western Ontario , Department of Medical Imaging, 1151 Richmond Street, London, Ontario N6A 3K7, Canada
| | - George Rodrigues
- London Regional Cancer Program, 790 Commissioners Road, London, Ontario N6A 4L6, Canada; University of Western Ontario, Department of Oncology, 1151 Richmond Street, London, Ontario N6A 3K7, Canada
| | - Belal Ahmad
- London Regional Cancer Program, 790 Commissioners Road, London, Ontario N6A 4L6, Canada; University of Western Ontario, Department of Oncology, 1151 Richmond Street, London, Ontario N6A 3K7, Canada
| | - Michael Lock
- London Regional Cancer Program, 790 Commissioners Road, London, Ontario N6A 4L6, Canada; University of Western Ontario, Department of Oncology, 1151 Richmond Street, London, Ontario N6A 3K7, Canada
| | - Aaron Fenster
- University of Western Ontario, Robarts Research Institute, 1151 Richmond Street, London, Ontario N6A 5B7, Canada; University of Western Ontario, Graduate Program in Biomedical Engineering, 1151 Richmond Street, London, Ontario N6A 3K7, Canada; University of Western Ontario, Department of Medical Imaging, 1151 Richmond Street, London, Ontario N6A 3K7, Canada; University of Western Ontario, Department of Medical Biophysics, 1151 Richmond Street, London, Ontario N6A 3K7, Canada
| | - Aaron D Ward
- London Regional Cancer Program, 790 Commissioners Road, London, Ontario N6A 4L6, Canada; University of Western Ontario, Graduate Program in Biomedical Engineering, 1151 Richmond Street, London, Ontario N6A 3K7, Canada; University of Western Ontario, Department of Medical Biophysics, 1151 Richmond Street, London, Ontario N6A 3K7, Canada; University of Western Ontario, Department of Oncology, 1151 Richmond Street, London, Ontario N6A 3K7, Canada
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Cool DW, Romagnoli C, Izawa JI, Chin J, Gardi L, Tessier D, Mercado A, Mandel J, Ward AD, Fenster A. Comparison of prostate MRI-3D transrectal ultrasound fusion biopsy for first-time and repeat biopsy patients with previous atypical small acinar proliferation. Can Urol Assoc J 2016; 10:342-348. [PMID: 27800057 DOI: 10.5489/cuaj.3831] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
INTRODUCTION This study evaluates the clinical benefit of magnetic resonance-transrectal ultrasound (MR-TRUS) fusion biopsy over systematic biopsy between first-time and repeat prostate biopsy patients with prior atypical small acinar proliferation (ASAP). MATERIALS 100 patients were enrolled in a single-centre prospective cohort study: 50 for first biopsy, 50 for repeat biopsy with prior ASAP. Multiparameteric magnetic resonance imaging (MP-MRI) and standard 12-core ultrasound biopsy (Std-Bx) were performed on all patients. Targeted biopsy using MRI-TRUS fusion (Fn-Bx) was performed f suspicious lesions were identified on the pre-biopsy MP-MRI. Classification of clinically significant disease was assessed independently for the Std-Bx vs. Fn-Bx cores to compare the two approaches. RESULTS Adenocarcinoma was detected in 49/100 patients (26 first biopsy, 23 ASAP biopsy), with 25 having significant disease (17 first, 8 ASAP). Fn-Bx demonstrated significantly higher per-core cancer detection rates, cancer involvement, and Gleason scores for first-time and ASAP patients. However, Fn-Bx was significantly more likely to detect significant cancer missed on Std-Bx for ASAP patients than first-time biopsy patients. The addition of Fn-Bx to Std-Bx for ASAP patients had a 166.7% relative risk reduction for missing Gleason ≥ 3 + 4 disease (number needed to image with MP-MRI=10 patients) compared to 6.3% for first biopsy (number to image=50 patients). Negative predictive value of MP-MRI for negative biopsy was 79% for first-time and 100% for ASAP patients, with median followup of 32.1 ± 15.5 months. CONCLUSIONS MR-TRUS Fn-Bx has a greater clinical impact for repeat biopsy patients with prior ASAP than biopsy-naïve patients by detecting more significant cancers that are missed on Std-Bx.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Aaron D Ward
- Department of Biophysics; University of Western Ontario, London, ON, Canada
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Gibson E, Bauman GS, Romagnoli C, Cool DW, Bastian-Jordan M, Kassam Z, Gaed M, Moussa M, Gómez JA, Pautler SE, Chin JL, Crukley C, Haider MA, Fenster A, Ward AD. Toward Prostate Cancer Contouring Guidelines on Magnetic Resonance Imaging: Dominant Lesion Gross and Clinical Target Volume Coverage Via Accurate Histology Fusion. Int J Radiat Oncol Biol Phys 2016; 96:188-96. [PMID: 27375167 DOI: 10.1016/j.ijrobp.2016.04.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 03/16/2016] [Accepted: 04/13/2016] [Indexed: 12/30/2022]
Abstract
PURPOSE Defining prostate cancer (PCa) lesion clinical target volumes (CTVs) for multiparametric magnetic resonance imaging (mpMRI) could support focal boosting or treatment to improve outcomes or lower morbidity, necessitating appropriate CTV margins for mpMRI-defined gross tumor volumes (GTVs). This study aimed to identify CTV margins yielding 95% coverage of PCa tumors for prospective cases with high likelihood. METHODS AND MATERIALS Twenty-five men with biopsy-confirmed clinical stage T1 or T2 PCa underwent pre-prostatectomy mpMRI, yielding T2-weighted, dynamic contrast-enhanced, and apparent diffusion coefficient images. Digitized whole-mount histology was contoured and registered to mpMRI scans (error ≤2 mm). Four observers contoured lesion GTVs on each mpMRI scan. CTVs were defined by isotropic and anisotropic expansion from these GTVs and from multiparametric (unioned) GTVs from 2 to 3 scans. Histologic coverage (proportions of tumor area on co-registered histology inside the CTV, measured for Gleason scores [GSs] ≥6 and ≥7) and prostate sparing (proportions of prostate volume outside the CTV) were measured. Nonparametric histologic-coverage prediction intervals defined minimal margins yielding 95% coverage for prospective cases with 78% to 92% likelihood. RESULTS On analysis of 72 true-positive tumor detections, 95% coverage margins were 9 to 11 mm (GS ≥ 6) and 8 to 10 mm (GS ≥ 7) for single-sequence GTVs and were 8 mm (GS ≥ 6) and 6 mm (GS ≥ 7) for 3-sequence GTVs, yielding CTVs that spared 47% to 81% of prostate tissue for the majority of tumors. Inclusion of T2-weighted contours increased sparing for multiparametric CTVs with 95% coverage margins for GS ≥6, and inclusion of dynamic contrast-enhanced contours increased sparing for GS ≥7. Anisotropic 95% coverage margins increased the sparing proportions to 71% to 86%. CONCLUSIONS Multiparametric magnetic resonance imaging-defined GTVs expanded by appropriate margins may support focal boosting or treatment of PCa; however, these margins, accounting for interobserver and intertumoral variability, may preclude highly conformal CTVs. Multiparametric GTVs and anisotropic margins may reduce the required margins and improve prostate sparing.
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Affiliation(s)
- Eli Gibson
- Robarts Research Institute, University of Western Ontario, London, Ontario, Canada; Biomedical Engineering, University of Western Ontario, London, Ontario, Canada; Centre for Medical Image Computing, University College London, London, UK; Department of Radiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Glenn S Bauman
- Lawson Health Research Institute, London, Ontario, Canada; Department of Oncology, University of Western Ontario, London, Ontario, Canada.
| | - Cesare Romagnoli
- Department of Medical Imaging, University of Western Ontario, London, Ontario, Canada
| | - Derek W Cool
- Department of Medical Imaging, University of Western Ontario, London, Ontario, Canada
| | - Matthew Bastian-Jordan
- Department of Medical Imaging, University of Western Ontario, London, Ontario, Canada; Queensland Health, Brisbane, Queensland, Australia
| | - Zahra Kassam
- Department of Medical Imaging, University of Western Ontario, London, Ontario, Canada
| | - Mena Gaed
- Robarts Research Institute, University of Western Ontario, London, Ontario, Canada; Department of Pathology, University of Western Ontario, London, Ontario, Canada
| | - Madeleine Moussa
- Department of Pathology, University of Western Ontario, London, Ontario, Canada
| | - José A Gómez
- Department of Pathology, University of Western Ontario, London, Ontario, Canada
| | - Stephen E Pautler
- Lawson Health Research Institute, London, Ontario, Canada; Department of Urology, University of Western Ontario, London, Ontario, Canada
| | - Joseph L Chin
- Lawson Health Research Institute, London, Ontario, Canada; Department of Urology, University of Western Ontario, London, Ontario, Canada
| | - Cathie Crukley
- Robarts Research Institute, University of Western Ontario, London, Ontario, Canada; Lawson Health Research Institute, London, Ontario, Canada
| | - Masoom A Haider
- Department of Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - Aaron Fenster
- Robarts Research Institute, University of Western Ontario, London, Ontario, Canada; Biomedical Engineering, University of Western Ontario, London, Ontario, Canada; Lawson Health Research Institute, London, Ontario, Canada; Department of Oncology, University of Western Ontario, London, Ontario, Canada; Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada
| | - Aaron D Ward
- Biomedical Engineering, University of Western Ontario, London, Ontario, Canada; Lawson Health Research Institute, London, Ontario, Canada; Department of Oncology, University of Western Ontario, London, Ontario, Canada; Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada; Baines Imaging Research Laboratory, London Regional Cancer Centre, London, Ontario, Canada
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Shahedi M, Cool DW, Romagnoli C, Bauman GS, Bastian-Jordan M, Gibson E, Rodrigues G, Ahmad B, Lock M, Fenster A, Ward AD. Spatially varying accuracy and reproducibility of prostate segmentation in magnetic resonance images using manual and semiautomated methods. Med Phys 2015; 41:113503. [PMID: 25370674 DOI: 10.1118/1.4899182] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Three-dimensional (3D) prostate image segmentation is useful for cancer diagnosis and therapy guidance, but can be time-consuming to perform manually and involves varying levels of difficulty and interoperator variability within the prostatic base, midgland (MG), and apex. In this study, the authors measured accuracy and interobserver variability in the segmentation of the prostate on T2-weighted endorectal magnetic resonance (MR) imaging within the whole gland (WG), and separately within the apex, midgland, and base regions. METHODS The authors collected MR images from 42 prostate cancer patients. Prostate border delineation was performed manually by one observer on all images and by two other observers on a subset of ten images. The authors used complementary boundary-, region-, and volume-based metrics [mean absolute distance (MAD), Dice similarity coefficient (DSC), recall rate, precision rate, and volume difference (ΔV)] to elucidate the different types of segmentation errors that they observed. Evaluation for expert manual and semiautomatic segmentation approaches was carried out. Compared to manual segmentation, the authors' semiautomatic approach reduces the necessary user interaction by only requiring an indication of the anteroposterior orientation of the prostate and the selection of prostate center points on the apex, base, and midgland slices. Based on these inputs, the algorithm identifies candidate prostate boundary points using learned boundary appearance characteristics and performs regularization based on learned prostate shape information. RESULTS The semiautomated algorithm required an average of 30 s of user interaction time (measured for nine operators) for each 3D prostate segmentation. The authors compared the segmentations from this method to manual segmentations in a single-operator (mean whole gland MAD = 2.0 mm, DSC = 82%, recall = 77%, precision = 88%, and ΔV = - 4.6 cm(3)) and multioperator study (mean whole gland MAD = 2.2 mm, DSC = 77%, recall = 72%, precision = 86%, and ΔV = - 4.0 cm(3)). These results compared favorably with observed differences between manual segmentations and a simultaneous truth and performance level estimation reference for this data set (whole gland differences as high as MAD = 3.1 mm, DSC = 78%, recall = 66%, precision = 77%, and ΔV = 15.5 cm(3)). The authors found that overall, midgland segmentation was more accurate and repeatable than the segmentation of the apex and base, with the base posing the greatest challenge. CONCLUSIONS The main conclusions of this study were that (1) the semiautomated approach reduced interobserver segmentation variability; (2) the segmentation accuracy of the semiautomated approach, as well as the accuracies of recently published methods from other groups, were within the range of observed expert variability in manual prostate segmentation; and (3) further efforts in the development of computer-assisted segmentation would be most productive if focused on improvement of segmentation accuracy and reduction of variability within the prostatic apex and base.
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Affiliation(s)
- Maysam Shahedi
- London Regional Cancer Program, London, Ontario N6A 5W9, Canada; Robarts Research Institute, The University of Western Ontario, London, Ontario N6A 3K7, Canada; and Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Derek W Cool
- Robarts Research Institute, The University of Western Ontario, London, Ontario N6A 3K7, Canadaand The Department of Medical Imaging, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Cesare Romagnoli
- The Department of Medical Imaging, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Glenn S Bauman
- London Regional Cancer Program, London, Ontario N6A 5W9, Canada; The Department of Medical Biophysics, The University of Western Ontario, London, Ontario N6A 3K7, Canada; and The Department of Oncology, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Matthew Bastian-Jordan
- The Department of Medical Imaging, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Eli Gibson
- Robarts Research Institute, The University of Western Ontario, London, Ontario N6A 3K7, Canada and Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - George Rodrigues
- London Regional Cancer Program, London, Ontario N6A 5W9, Canada and The Department of Oncology, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Belal Ahmad
- London Regional Cancer Program, London, Ontario N6A 5W9, Canada and The Department of Oncology, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Michael Lock
- London Regional Cancer Program, London, Ontario N6A 5W9, Canada and The Department of Oncology, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Aaron Fenster
- Robarts Research Institute, The University of Western Ontario, London, Ontario N6A 3K7, Canada; Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario N6A 3K7, Canada; The Department of Medical Biophysics, The University of Western Ontario, London, Ontario N6A 3K7, Canada; and The Department of Medical Imaging, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Aaron D Ward
- London Regional Cancer Program, London, Ontario N6A 5W9, Canada; Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario N6A 3K7, Canada; The Department of Medical Biophysics, The University of Western Ontario, London, Ontario N6A 3K7, Canada; and The Department of Oncology, The University of Western Ontario, London, Ontario N6A 3K7, Canada
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Martin PR, Cool DW, Romagnoli C, Fenster A, Ward AD. Magnetic resonance imaging-targeted, 3D transrectal ultrasound-guided fusion biopsy for prostate cancer: Quantifying the impact of needle delivery error on diagnosis. Med Phys 2015; 41:073504. [PMID: 24989418 DOI: 10.1118/1.4883838] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Magnetic resonance imaging (MRI)-targeted, 3D transrectal ultrasound (TRUS)-guided "fusion" prostate biopsy intends to reduce the ∼23% false negative rate of clinical two-dimensional TRUS-guided sextant biopsy. Although it has been reported to double the positive yield, MRI-targeted biopsies continue to yield false negatives. Therefore, the authors propose to investigate how biopsy system needle delivery error affects the probability of sampling each tumor, by accounting for uncertainties due to guidance system error, image registration error, and irregular tumor shapes. METHODS T2-weighted, dynamic contrast-enhanced T1-weighted, and diffusion-weighted prostate MRI and 3D TRUS images were obtained from 49 patients. A radiologist and radiology resident contoured 81 suspicious regions, yielding 3D tumor surfaces that were registered to the 3D TRUS images using an iterative closest point prostate surface-based method to yield 3D binary images of the suspicious regions in the TRUS context. The probabilityP of obtaining a sample of tumor tissue in one biopsy core was calculated by integrating a 3D Gaussian distribution over each suspicious region domain. Next, the authors performed an exhaustive search to determine the maximum root mean squared error (RMSE, in mm) of a biopsy system that gives P ≥ 95% for each tumor sample, and then repeated this procedure for equal-volume spheres corresponding to each tumor sample. Finally, the authors investigated the effect of probe-axis-direction error on measured tumor burden by studying the relationship between the error and estimated percentage of core involvement. RESULTS Given a 3.5 mm RMSE for contemporary fusion biopsy systems,P ≥ 95% for 21 out of 81 tumors. The authors determined that for a biopsy system with 3.5 mm RMSE, one cannot expect to sample tumors of approximately 1 cm(3) or smaller with 95% probability with only one biopsy core. The predicted maximum RMSE giving P ≥ 95% for each tumor was consistently greater when using spherical tumor shapes as opposed to no shape assumption. However, an assumption of spherical tumor shape for RMSE = 3.5 mm led to a mean overestimation of tumor sampling probabilities of 3%, implying that assuming spherical tumor shape may be reasonable for many prostate tumors. The authors also determined that a biopsy system would need to have a RMS needle delivery error of no more than 1.6 mm in order to sample 95% of tumors with one core. The authors' experiments also indicated that the effect of axial-direction error on the measured tumor burden was mitigated by the 18 mm core length at 3.5 mm RMSE. CONCLUSIONS For biopsy systems with RMSE ≥ 3.5 mm, more than one biopsy core must be taken from the majority of tumors to achieveP ≥ 95%. These observations support the authors' perspective that some tumors of clinically significant sizes may require more than one biopsy attempt in order to be sampled during the first biopsy session. This motivates the authors' ongoing development of an approach to optimize biopsy plans with the aim of achieving a desired probability of obtaining a sample from each tumor, while minimizing the number of biopsies. Optimized planning of within-tumor targets for MRI-3D TRUS fusion biopsy could support earlier diagnosis of prostate cancer while it remains localized to the gland and curable.
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Affiliation(s)
- Peter R Martin
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Derek W Cool
- Department of Medical Imaging, The University of Western Ontario, London, Ontario N6A 3K7, Canada and Robarts Research Institute, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Cesare Romagnoli
- Department of Medical Imaging, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Aaron Fenster
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario N6A 3K7, Canada; Department of Medical Imaging, The University of Western Ontario, London, Ontario N6A 3K7, Canada; and Robarts Research Institute, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Aaron D Ward
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario N6A 3K7, Canada and Department of Oncology, The University of Western Ontario, London, Ontario N6A 3K7, Canada
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De Silva T, Cool DW, Romagnoli C, Fenster A, Ward AD. Evaluating the utility of intraprocedural 3D TRUS image information in guiding registration for displacement compensation during prostate biopsy. Med Phys 2014; 41:082901. [DOI: 10.1118/1.4885959] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Neshat H, Cool DW, Barker K, Gardi L, Kakani N, Fenster A. A 3D ultrasound scanning system for image guided liver interventions. Med Phys 2013; 40:112903. [DOI: 10.1118/1.4824326] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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Chalasani V, Cool DW, Sherebrin S, Fenster A, Chin J, Izawa JI. Development and validation of a virtual reality transrectal ultrasound guided prostatic biopsy simulator. Can Urol Assoc J 2013. [DOI: 10.5489/cuaj.554] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Objective: We present the design, reliability, face, content andconstruct validity testing of a virtual reality simulator for transrectalultrasound (TRUS), which allows doctors-in-training to performmultiple different biopsy schemes.Methods: This biopsy system design uses a regular “end-firing”TRUS probe. Movements of the probe are tracked with a micromagneticsensor to dynamically slice through a phantom patient’s3D prostate volume to provide real-time continuous TRUS views.3D TRUS scans during prostate biopsy clinics were recorded.Intrinsic reliability was assessed by comparing the left side of theprostate to the right side of the prostate for each biopsy. A contentand face validity questionnaire was administered to 26 doctors toassess the simulator. Construct validity was assessed by comparingnotes from experts and novices with regards to the time taken andthe accuracy of each biopsy.Results: Imaging data from 50 patients were integrated into thesimulator. The completed VR TRUS simulator uses real patientimages, and is able to provide simulation for 50 cases, with ahaptic interface that uses a standard TRUS probe and biopsy needle.Intrinsic reliability was successfully demonstrated by comparingresults from the left and right sides of the prostate. Face andcontent validity respondents noted the realism of the simulator,and its appropriateness as a teaching model. The simulator wasable to distinguish between experts and novices during constructvalidity testing.Conclusions: A virtual reality TRUS simulator has successfully beencreated. It has promising face, content and construct validity results.
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De Silva T, Fenster A, Cool DW, Gardi L, Romagnoli C, Samarabandu J, Ward AD. 2D-3D rigid registration to compensate for prostate motion during 3D TRUS-guided biopsy. Med Phys 2013; 40:022904. [DOI: 10.1118/1.4773873] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Cool DW, Romagnoli C, Izawa JI, Chin J, Gardi L, Ward AD, Fenster A. 2031 ENHANCED TUMOUR SAMPLING AND GLEASON GRADING THROUGH FUSION OF MRI TO 3D TRANSRECTAL ULTRASOUND (TRUS) BIOPSY. J Urol 2012. [DOI: 10.1016/j.juro.2012.02.2195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chalasani V, Cool DW, Sherebrin S, Fenster A, Chin J, Izawa JI. Development and validation of a virtual reality transrectal ultrasound guided prostatic biopsy simulator. Can Urol Assoc J 2011; 5:19-26. [PMID: 21470507 DOI: 10.5489/cuaj.09159] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE We present the design, reliability, face, content and construct validity testing of a virtual reality simulator for transrectal ultrasound (TRUS), which allows doctors-in-training to perform multiple different biopsy schemes. METHODS This biopsy system design uses a regular "end-firing" TRUS probe. Movements of the probe are tracked with a micro-magnetic sensor to dynamically slice through a phantom patient's 3D prostate volume to provide real-time continuous TRUS views. 3D TRUS scans during prostate biopsy clinics were recorded. Intrinsic reliability was assessed by comparing the left side of the prostate to the right side of the prostate for each biopsy. A content and face validity questionnaire was administered to 26 doctors to assess the simulator. Construct validity was assessed by comparing notes from experts and novices with regards to the time taken and the accuracy of each biopsy. RESULTS Imaging data from 50 patients were integrated into the simulator. The completed VR TRUS simulator uses real patient images, and is able to provide simulation for 50 cases, with a haptic interface that uses a standard TRUS probe and biopsy needle. Intrinsic reliability was successfully demonstrated by comparing results from the left and right sides of the prostate. Face and content validity respondents noted the realism of the simulator, and its appropriateness as a teaching model. The simulator was able to distinguish between experts and novices during construct validity testing. CONCLUSIONS A virtual reality TRUS simulator has successfully been created. It has promising face, content and construct validity results.
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Affiliation(s)
- Venu Chalasani
- Departments of Surgery & Oncology, Divisions of Urology & Surgical Oncology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON
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Cool DW, Gardi L, Romagnoli C, Saikaly M, Izawa JI, Fenster A. Temporal-based needle segmentation algorithm for transrectal ultrasound prostate biopsy procedures. Med Phys 2010; 37:1660-73. [PMID: 20443487 DOI: 10.1118/1.3360440] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Automatic identification of the biopsy-core tissue location during a prostate biopsy procedure would provide verification that targets were adequately sampled and would allow for appropriate intraprocedure biopsy target modification. Localization of the biopsy core requires accurate segmentation of the biopsy needle and needle tip from transrectal ultrasound (TRUS) biopsy images. A temporal-based TRUS needle segmentation algorithm was developed specifically for the prostate biopsy procedure to automatically identify the TRUS image containing the biopsy needle from a collection of 2D TRUS images and to segment the biopsy-core location from the 2D TRUS image. METHODS The temporal-based segmentation algorithm performs a temporal analysis on a series of biopsy TRUS images collected throughout needle insertion and withdrawal. Following the identification of points of needle insertion and retraction, the needle axis is segmented using a Hough transform-based algorithm, which is followed by a temporospectral TRUS analysis to identify the biopsy-needle tip. Validation of the temporal-based algorithm is performed on 108 TRUS biopsy sequences collected from the procedures of ten patients. The success of the temporal search to identify the proper images was manually assessed, while the accuracies of the needle-axis and needle-tip segmentations were quantitatively compared to implementations of two other needle segmentation algorithms within the literature. RESULTS The needle segmentation algorithm demonstrated a >99% accuracy in identifying the TRUS image at the moment of needle insertion from the collection of real-time TRUS images throughout the insertion and withdrawal of the biopsy needle. The segmented biopsy-needle axes were accurate to within 2.3 +/- 2.0 degrees and 0.48 +/- 0.42 mm of the gold standard. Identification of the needle tip to within half of the biopsy-core length (<10 mm) was 95% successful with a mean error of 2.4 +/- 4.0 mm. Needle-tip detection using the temporal-based algorithm was significantly more accurate (p < 0.001) than the other two algorithms tested, while the segmentation of the needle axis was not significantly different between the three algorithms. CONCLUSIONS The temporal-based needle segmentation algorithm accurately segments the location of the biopsy core from 2D TRUS images of clinical prostate biopsy procedures. The results for needle-tip localization demonstrated that the temporal-based algorithm is significantly more accurate than implementations of some existing needle segmentation algorithms within the literature.
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Affiliation(s)
- Derek W Cool
- Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8, Canada.
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Cool DW, Connolly MJ, Sherebrin S, Eagleson R, Izawa JI, Amann J, Romagnoli C, Romano WM, Fenster A. Repeat Prostate Biopsy Accuracy: Simulator-based Comparison of Two- and Three-dimensional Transrectal US Modalities. Radiology 2010; 254:587-94. [DOI: 10.1148/radiol.2542090674] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Karnik VV, Fenster A, Bax J, Cool DW, Gardi L, Gyacskov I, Romagnoli C, Ward AD. Assessment of image registration accuracy in three-dimensional transrectal ultrasound guided prostate biopsy. Med Phys 2010; 37:802-13. [PMID: 20229890 DOI: 10.1118/1.3298010] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- V V Karnik
- Biomedical Engineering Graduate Program, The University of Western Ontario, London, Ontario N6A 5C1, Canada.
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