Transcript Slides-23-40

Safety Consideration
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Software limits on robot controller
Limit switches on the robot “wrist” to prevent excess
rotations
Limit switches on the vertical travel
Contact detection on upper arm of robot
Enable button on hand pendant
E-Stop button on hand controller
Couch can lower for patient egress during power
outage
Case Study 2
Automated Motion Correction –
Tracking the Spine
Challenges of Spinal Treatments
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The spine moves during treatment
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Vertebrae can move independent of one
another
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Rigid transformation is not valid in most
cases
Adjacent structures (spinal cord) necessitate
high precision and accuracy
Traditional Radiation Therapy
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Difficult to adequately immobilize the patient,
internal structures, & the target
Image guidance (IGRT) confirms treatment setup
but no compensation for target movement during
the treatment
Implanted markers can increase accuracy but
introduce additional challenges
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Invasive
Delays time-to-treatment
Spine Tracking
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Non-invasively registers non-rigid and bony anatomy
landmarks
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Internal markers or frames not required
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Automatically tracks spine from DRR image pairs
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Cervical, thoracic, lumbar and sacral
Sub-millimeter targeting accuracy, (0.52 +/- 0.22 mm)† ‡
† As measured in end-to-end testing. Reference: Muacevic, A., Staehler, M., Drexler, C., Wowra, B., Reiser, M. and Tonn, J. Technical description,
phantom accuracy and clinical feasibility for fiducial-free frameless real-time image-guided spinal radiosurgery. J Neurosurgery Spine.
‡ Xsight accuracy specification of .95 mm.
How it Works…
Step 1
3
2
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Hierarchical Mesh Tracking
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Identifies unique bony
structures
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Enables registration of
non-rigid
skeletal anatomy
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Estimates local
displacements in
bony features
How it Works…
DRR (from CT)
Image A
Image B
Live kV image
Displacement Field
Spine Tracking Animation
Case Study 3
Automated Motion Compensation –
Tracking Respriation
Respiratory Tracking
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Challenges of respiratory motion
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Respiratory-induced motion of
tumors causes significant
targeting uncertainty
• Lung, liver, and pancreas
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Traditional radiation therapy
margins are not optimized for
high-dose radiosurgery
Traditional Radiation Therapy
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Solutions for compensating for motion plagued with
repeatability and compliance issues
Healthy tissues is unnecessarily treated
Respiratory Tracking
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Tightly contoured beams following
tumor motion in real-time
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Delivers throughout the respiratory
cycle without gating or breathholding
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Instantly adapts to variations in
breathing patterns
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Proven accuracy
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Systemic error of 0.70 +/0.33mm† ‡
† Reference: Dieterich S, Taylor D, Chuang C, Wong
K, Tang J, Kilby W, Main W. The CyberKnife
Synchrony Respiratory Tracking System: Evaluation of
Systematic Targeting Uncertainty.
‡Synchrony clinical accuracy specification of 1.5 mm for
moving targets.
How It Works… (1)
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Two features to form the basis for accuracy
Gold markers, implanted
prior to treatment
LED markers on a
special patient vest
How It Works… (2)
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Prior to treatment start: creation of dynamic correlation
model
Imaging system takes positions of
markers at discrete points of time
LED’s are monitored in real
time by a camera system
How It Works… (2)
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Prior to treatment start: creation of dynamic correlation
model
Markers are monitored in real time
by a camera system
displacement
displacement
Imaging system takes positions
of fiducials at discrete points of
time
time
time
How It Works… (3)
displacement
This process repeats throughout the treatment, updating
and correcting beam delivery based upon the patient’s
current breathing pattern
displacement
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time
time
Synchrony Animation
Summary
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There is a place for autonomous robotics in
medicine
Special consideration must me taken to adapt to
dynamic environment
Safety is most important requiring redundancy
throughout
Greater demand for precision and accuracy will
pave the way for future applications