Clinical Implementation of Robotic Systems
for Brachytherapy
Tarun K. Podder, PhD, DABR
Assistant Professor
Department of Radiation Oncology
Kimmel Cancer center (NCI-designated)
Thomas Jefferson University
Philadelphia, PA 19107
AAPM Annual Meeting
July 19, 2010
Robot-assisted Surgical Paradigm
• Point & Click Surgery
• One Stop Shopping
• Plug & Play Surgery
– close the loop in the image
– plan, do, and validate
– rapid assembly and certification
Coordinates
Imager: CT,MRI,
US, X-ray
Assistant
device (robot)
Planning &
control
computer
Physician
Patient
Digital images
Fichtinger et al. IEEE AIPR, 2001
T.K. Podder, AAPM July 2010
Learning Objectives
1. Review the imaging modalities used for robot-assisted
seed implantation
2. Understand the brachytherapy robotic system calibration
3. Understand the commissioning and QA procedures and
issues
4. Understand the safety and reliability issues for
introducing robotic systems in the clinic
T.K. Podder, AAPM July 2010
Imaging modalities used for robot-assisted barchytherapy
• Image-guidance is one of the main aspects of
brachytherapy for accuracy and consistency of
seed implantation
• Modalities such as U/S, CT, and MR have been
integrated with the robots for performing the
clinical procedures
• U/S is the most commonly used
T.K. Podder, AAPM July 2010
Imaging modalities used for robot-assisted barchytherapy
Ultrasound (U/S) Imaging
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TRUS (single plan, bi-plane, 3D, doppler)
image quality
variable slice spacing
cost effective, widely used
T.K. Podder, AAPM July 2010
Transrectal Ultrasound (TRUS)
Imaging modalities used for robot-assisted barchytherapy
Robotic prostate access in CT – 1999
CT Imaging
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patient positioning
contouring
limited use
Fichtinger et al. Acad Rad, 2001
T.K. Podder, AAPM July 2010
Imaging modalities used for robot-assisted barchytherapy
JHU-NIH
• From concept to 2 trials in 22 mo
• 120+ biopsies & marker seed
placements
• No severe adverse events
• Supports various clinical trials
MR Imaging
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better soft tissue contrast
1.5T-3T
patient positioning
rectal MR probe (JHU)
Susil et al. J Urology, 2006
T.K. Podder, AAPM July 2010
Robot Calibration
Robot
Kinematic
Calibration
YR
Robot Base
Frame
Yw
ZR
Fixed Ref.
Frame
XR
Zw
Xw
Direct
Kinematics
Encoder
feedback
Prostate
(xt, yt, zt)
seed coordinates
YI
XI
ZI
TRUS Ref.
Frame
TRUS Probe
Overall System
Calibration
T.K. Podder, AAPM July 2010
Image
Calibration
Podder, ABS Prostate School 2008
Commissioning and QA
• Satisfactory acceptance testing assures that the robotic
system satisfies all agreed-upon specifications between
the vendor and the buyer
• Commissioning of a robot for clinical use should include:
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verification of dosimetric planning system
testing of robot’s accuracy and functionalities
development of operational procedures,
training of all concerned with the operation of the
robotic system
• Quality assurance (QA):
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T.K. Podder, AAPM July 2010
check before each case
monthly QA
quarterly check
annual QA
Commissioning and QA
In addition to the traditional tests for brachytherapy,
several additional items must be tested before
commissioning the robotic system and should be
periodically evaluated following a quality assurance
program.
T.K. Podder, AAPM July 2010
Preoperative Quality Assurance of EUCLIDIAN - Image-guided Robotic
System for Prostate Brachytherapy
I
QA check prior to
the procedure
MECHANICAL SCREENING TEST
1 Visual check
Connectors
Controllers
Wires
Sensors
Controllers
Motors
Encoders
Moving parts
Readings
Sensitivity
Motors
Overall
outcome
2 Connectivity
outcome
3 Sensors
outcome
4 Needling Mechanicm
outcome
5 Other
Cannula
instalation
Stylet
instalation
Sterilizing
parts
Emergency
button
Translation
knob
Rotation
knob
outcome
II ROBOT FUNCTIONALITY TEST
1 Hardware detection
Controllers
outcome
2 Mobility
Probe stage
Frame
Frabber
Sensors
Emergency
buttons
Needling XVZ platform
mechanism
motion
X
outcome
Import
images
3 Case test
Y
Quick plan
outcome
III IMAGING MODULE TEST
1 Image calibration
2 Precision
T.K. Podder, AAPM July 2010
Physicist
Grid
matching test
difference
yes/no
Accuracy
measure 1 - point 1
measure 1 - point 2
measure 2 - point 1
measure 2 - point 2
X
Y
Z
Z
Buzurovic, Podder, Yu, et al.,
AAPM 2008
Date
Prostate Deformation & Displacement
Prostate
Capsule
Prostate
Capsule
Needle
Prostate
Capsule
Needle
(a) Prior to capsule puncture
(b) During capsule puncture
(c) After full insertion
TRUS Images of prostate during brachytherapy
needle insertion,
T.K. Podder, AAPM July 2010
Needle
Techniques for Prostate Immobilization
Template
Seed Cartridge
Techniques:
Needle
• No stabilization needle
Applicator
• Parallel regular needle
TRUS
• Parallel hook needle
• Angulated regular needle
(a)
• Angulated hook needle
Insertion
Needle
Seed Cartridge
Needle angulation:
• In sagittal plane
Prostate
Stabilizing
Needles
• In both sagittal and coronal planes
TRUS
Hook needle
Regular needle
(b)
Robotic systems – no physical template.
How to immobilize the prostate?
Podder et al., PMB 2008
Techniques for Prostate Immobilization
T.K. Podder, AAPM July 2010
Safety and reliability
• Clinical environment is complex and constrained
• Interaction between the robot and the patient is
extremely important
• Brachytherapy robotic systems carry a surgical tool
(needle) and radioactive seeds and come in contact with
the patient as well as close proximity to the clinical staffs
• Robustness and reliability of the robotic systems must
be evaluated
• Cleaning, decontamination and sterilization
(needle and
seed passage)
• Pre-clinical accelerated tests and FMEA
Effect Analysis)
T.K. Podder, AAPM July 2010
(Failure Mode and
Safety and reliability
T.K. Podder, AAPM July 2010
Cleaning and decontamination
T.K. Podder, AAPM July 2010
FINISH
START
Clinical workflow
Clinical workflow of an advanced brachytherapy robotic system
T.K. Podder, AAPM July 2010
Podder, Yu et al. 2010
Clinical implementation of a new device
• IEC-60601 compliance
• FDA approval
• IRB approval
• Training of personnel
• AAPM Task Group recommendations (TG-192 started Sept 2009)
T.K. Podder, AAPM July 2010
T.K. Podder, AAPM July 2010
Summary and Conclusion
• Image-guidance is very important for accuracy and
consistency of seed implantation
• Imaging modalities such as U/S, CT, and MR – integrated
with the brachytherapy robots
• Proper calibration, appropriate testing, and commissioning
of the integrated system are critical
• Accelerated tests and FMEA
• SAUR (Safety, Accuracy, User-friendliness, and Reliability) - critical
for clinical implementation of any medical device
• Periodic QA of the system is important
• FDA and IRB approvals
• AAPM-TG 192 recommendations (when available)
T.K. Podder, AAPM July 2010