Objectives
Joint Imaging/Therapy Symposium
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Targeting Using Surrogates
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Fang-Fang Yin, PhD (Duke University)
Mack Roach, MD (University of California at San Francisco)
Hiroki Shirato, MD, PhD (Hokkaido University)
James Balter, PhD (University of Michigan)
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To discuss the various types of tumor surrogates, both
anatomical and implanted, used for radiation therapy
targeting
To discuss techniques for identifying or implanting
surrogates
To discuss in-room localization or imaging techniques
for different surrogates, including the relationship
between immobilization and surrogate fidelity
To discuss the application of different surrogates,
clinical feasibility and efficacy, and limitations
To discuss quality assurance procedures and programs
To discuss current challenges and future directions
AAPM Symposium, July 2008
Disclosures
• F Yin: partial research supports from Varian Medical
Systems, GE Health Care grants
• J Balter: Scientific Advisor, Calypso Medical
Technologies
• H Shirato: Fund from 1) Olympus col. ltd, 2) Tanaka
Kikinzoku Group for gold marker. Listed a an
inventor of marker insertion kit for lung lesions.
• M Roach:
Surrogates and Imaging Techniques
• Anatomical surrogates
• Diaphram
• Bony structures
• Tumor
• Implanted surrogates
• Gold seeds
• Coils
• Devices
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Surrogates and Imaging Techniques
Radio-opaque Surrogates
IBA Visicoil
alpha-Omega Services
• Radiographic imaging
Sicel
LZI Medical
Civco
Calypso
Carbon markers
– 2D Radiographic imaging
– 2-D Fluoroscopic imaging
– 3-D cone-beam CT (CBCT)
– 3-D digital tomosynthesis (DTS)
– 4-D CBCT and DTS
• Electromagnetic imaging
• Optical imaging (IR, laser, etc.)
Courtesy of SuperDimension
Anatomic Surrogate Imaging: Bony
kV sources
Anatomic Surrogate Imaging:
Soft Tissue
Target
Sim-CT
Reference image
CBCT match
to Sim-CT
Optical
kV imager
MV Imager
Portal image
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Anatomic Surrogate Imaging:
Soft Tissue and Isodose
Anatomic Surrogate Imaging:
Soft Tissue and Isodose
CBCT
Planning CT
PTV
Onboard verification
50% isodose line
Verifying Tx
isodose line
relative to PTV
PlanCT
50Gy
CBCT MRPTV
@isocenter
40Gy
Anatomic Surrogate Imaging:
Soft Tissue and Isodose
Anatomic Surrogate Imaging:
Soft Tissue and Breath-hold
Stomach
CBCT
15Gy
24Gy
20 portal images in cine
mode with < 1 s interval
Planning CT
RADIATION ONCOLOGY
DUKE UNIVERSITY
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Anatomic Surrogate Imaging:
Soft Tissue and Motion
Anatomic Surrogate Imaging:
Soft Tissue and Treatment Field
Breath-Hold
Free-breathing
ITV
Cine portal images
Treatment plan
Implanted Surrogate Imaging: Seeds
Prior to correction
After correction or
during treatment
After treatment
Implanted Surrogate Imaging: Coils
kV radiograph
and/or
fluoroscopic
images
Example of dual x-ray imaging
Courtesy of SuperDimension
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Implanted Surrogate Imaging:
Liver Clips with Breath-Hold
kV AP image
kV Lat image
Optical Surrogate Imaging: Surface
kV DTS image
Chen AAPM Summer Sch. 2006
Optical Surrogate
Imaging: Surface
Anatomic Surrogate Imaging:
Ultrasound
IR Image-Guided
Image-Guided
IR
Patient Positioning
Positioning
Patient
http://www.cmsrtp.com
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Implanted Surrogate Imaging:
Electromagnetic Signal
Soft Tissue Surrogate Imaging: MRI?
PTV
Onboard verification
50% isodose line
Verifying Tx
isodose line
relative to PTV
Under development (MR + Co-60)
Renaissance™ System 1000
www.viewray.com
PlanCT
Kupelian, et al IJROBP 2007
Functional Surrogate Imaging?
CBCT MRPTV
Onboard Surrogate Interference
Patient setup
On-board images
Reference images
Correction?
Y
N
0.35 mCi Tc-99m line-sources,
Bowsher et al 2006 AAPM
Shift couch
Feedback
On-board images
Treatment
On-board images
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Summary
• Various types of tumor surrogates, both
anatomical and implanted, are being used for
radiation therapy targeting
• In-room localization or imaging techniques
are available for different surrogates
• Selection of surrogates and imaging
technique should be determined based on
treatment site and immobilization method
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