![Page 1: Nathaniel Hayward Department of Medical Biophysics The University of Western Ontario Supervisor: Aaron Fenster](https://reader036.vdocuments.us/reader036/viewer/2022062313/56649cea5503460f949b4c70/html5/thumbnails/1.jpg)
Testing 3D Ultrasound with Image-Guided Robotics for
Prostate Brachytherapy
Nathaniel HaywardDepartment of Medical BiophysicsThe University of Western Ontario
Supervisor: Aaron Fenster
![Page 2: Nathaniel Hayward Department of Medical Biophysics The University of Western Ontario Supervisor: Aaron Fenster](https://reader036.vdocuments.us/reader036/viewer/2022062313/56649cea5503460f949b4c70/html5/thumbnails/2.jpg)
Prostate Cancer• The most commmon non-skin cancer among Canadian men
• 25, 500 men will be diagnosed this year• 4, 400 of these cases will be fatal
•Treatments of Prostate Cancer• Irradiation of Prostate Externally:
• Troubled Urination, Irritation
• Complete Prostatectomy:• Incontinence, Impotence, Altered Bowel Habits
• Prostate Brachytherapy:• Troubled Urination (Short-Term),Impotence
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Bladder
Needle Pre-Loaded with Iodine25 Seeds
Standard Brachytherapy Procedures
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Prostate Brachytherapy
• Used to treat early localised prostate cancer tumours•Utilises implantation of radioactive seeds
• Seeds deliver a local high-dose radiation that decreases •Less damaging than other irradiation techniques as the
seeds are implanted directly into the prostate
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Standard Brachytherapy Procedures
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3-D Ultrasound Method
• Sound Waves sent and received at different angles•Returning echoes are processed by a computer which reconstructs a 3-D image•Works much like a CT scan that utilises multiple x-rays (true image)
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Standard Brachytherapy Procedures
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Image Quality vs. Real-Time
• There is a trade-off between quality and how fast the image is processed.• Why is this important?
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• Needles are guided parallel to TRUS transducer• 5mm increments limit lateral positioning
•Prostate changes position during procedure• Need constant adjustment, Labour intensive for physician
•Enlarge Prostates – sections occluded by patients pubic arch• Parallel insertion completely miss these areas and lead to
insufficient dose coverage
The Problem
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Prostate Phantom Testing
• Allows for testing of brachytherapy procedures
•Prostate mold is cast from a stereo-lithograph of a real patient
•Mold injected with molten agar and left to cool (Clear)
•Background agar is created to fill the rest of the box (Opaque)
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Needle Needle
•Image-guided robotics receiving real-time updates• Removes problem of pubic arch interference
•Previous Attempts have distinct advantages• Respective procedures are still invasive
•Current project utilises physician• Robot loads, and positions needle
The Solution
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Robot Accuracy
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Needle Accuracy vs. Resolution
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Robot Accuracy
• Needle accuracy of actual target vs. “true” measurement and measurement using 3D-guided Robotics
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Future Work
• Testing on human subjects• Give a better feel for different sized prostates and
accuracies
• Reduce the size of the robot• Portability, Improve physician accuracy
• Improve design to work with larger angles• Increases success of brachytherapy especially in patients
with enlarged prostates
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Acknowledgements
• Jeffrey Bax•David Smith•Laura Bartha•Jacques Montreuil•Shi Sherebrin•Lori Gardi•Chandima Edirisinghe
• Aaron Fenster - Supervisor•Adam Krasinski- Supervisor
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References
• Bax J, Fenster A, Montreuil J, Gardi L, Smith D. Apparatus And Method For Guiding Insertion of a Medical Tool. US Patent Application
No: 11/427,121: Filed June 28, 2007 (Pending). • Fenster A, Downey DB, Cardinal HN. Three-dimensional ultrasound imaging. Physics in Medicine & Biology. 2001 ;46R67-R99.
•D.W. Rickey, P.A. Picot, D.A. Christopher, and A. Fenster, “A Wall-less Vessel Phantom for Doppler Ultrasound Studies,” Ultrasound in Med. & Biol 21(9), pp.1163-1176, 1995.