The 4D Phantom

1
The 4-D Phantom

• Kate Malinowski
• Marina Fooks
• Alex St. John
• Mentor Dr. Parag Parikh

2
The General Problem

• Respiratory tumor motion
• Radiation therapy technique
• Existing verification for stationary radiation
• Need for verification of dynamic radiation therapy

Radiation solid water phantom
3
Our Specific Problem

• Existing 3-D Phantom prototype
• Shortcomings of prototype

4
Design Specifications

• Move phantom in 3 dimensions
• Fit into radiation machines
• Movement 4cm in each direction, up to 5 cm/s
• Accuracy position within 0.2mm, timing within
  0.1
• Support 15lb phantom
• Portable by one person (lt40lbs)
• Be able to line up with axes
• Records motion carried out
• Cost lt 15K

5
Design Specifications

• Include integrated fourth motor
• Feedback on actual motion
• Adjustable angle on support arm
• Easy-to-use graphical interface
• Easy initialization/calibration
• Attach securely to treatment couch
• Controllable from distance of 50 ft (cable width)

6
Existing Solutions and Patents

• Thorax Phantom Computerized Imaging Reference
  Systems, Inc.
• Authentic Lung Tumor Phantom Olsen et al. US
  Patent 5,266,035
• Dynamic Phantom CIRS, Inc. Patent pending
• One-dimensional dynamic IMRT phantom Jiang et
  al (Harvard). US Patent 4,646,334
• 1.5-dimensional dynamic phantom Goddu et al
  (Washington University)
• Real-time Position Management Varian Medical
  Systems
• 4-D Phantom prototype Parikh et al (Washington
  University)

7
Existing Solutions and Patents

• Thorax Phantom Computerized Imaging Reference
  Systems, Inc.
• Authentic Lung Tumor Phantom Olsen et al. US
  Patent 5,266,035
• Dynamic Phantom CIRS, Inc. Patent pending
• One-dimensional dynamic IMRT phantom Jiang et
  al (Harvard). US Patent 4,646,334
• 1.5-dimensional dynamic phantom Goddu et al
  (Washington University)
• Real-time Position Management Varian Medical
  Systems
• 4-D Phantom prototype Parikh et al (Washington
  University)

8
Existing Solutions and Patents

• Dynamic Phantom
• Made by Computerized Imaging Reference Systems,
  Inc.
• Patent pending
• 3-D motion, but limited

CIRS Dynamic Phantom, 2005
9
Existing Solutions and Patents

• One-dimensional dynamic IMRT phantom
• Made by Jiang et al at Harvard University
• US Patent 4646334
• Only one dimension

Jiang et al, 2003
10
Existing Solutions and Patents

• 1.5-dimensional dynamic phantom
• Made by Goddu et al at Washington University
• Similar to Jiangs, but with added surrogate
• Still, limited motion

11
Existing Solutions and Patents

• Real-time Position Management
• Made by Varian Medical Systems
• Uses retro-reflective monitor to control gated
  radiation
• Our system must be compatible

Wong et al, 2003
12
Existing Solutions and Patents

• 4-D Phantom prototype
• Made by Parikh et al at Washington University
• Good, but needs improvement

Amplifier
Positional feedback arm
Support arm for phantom
Phantom
3-axis motor configuration
13
Literature Search
14
Preliminary Analysis

• Measurements of CT bores

15
Preliminary Analysis

• Calculate maximum allowable height of support
  arm
• 42 H2 132
• H 12.4
• Space above phantom to top of bore 0.6
• Height of bottom of phantom above treatment table
  18.5 0.6 8 9.9

16
Preliminary Analysis

• Torque due to phantom
• (Assume 20 lb phantom measuring 8x8x8)

17
Design Schedule
18
Team Organization

• Kate Malinowski
• Hardware considerations
• Software development
• Final presentation
• Marina Fooks
• Preliminary analysis
• Research parts and prices
• Ergonomics
• Progress report presentation
• Alex St. John
• Mechanical drawings
• DesignSafe analysis
• Preliminary presentation

19
References

• Acharya, et. al. Dynamic phantom and method for
  evaluating calcium scoring. USPTO Patent
  Full-Text and Image Database. February 24, 2004.
  6,697,451. www.uspto.gov
• Constantine, C., et. al. A solid water phantom.
  Medical Physics. (1982). www.pubmed.com

20
Questions?