Treatment Verification with Cherenkov...
Transcript of Treatment Verification with Cherenkov...
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Treatment Verification with Cherenkov Imaging
Brian W Pogue PhD MacLean Professor of Engineering, Dartmouth
Editor-in-Chief, Journal of Biomedical Optics
Dose imaging?Beam Tracking Cherenkov emission from eye
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Disclosures
DoseOptics LLC: President and co-founder
Developing Cherenkov imaging cameras software and systems.
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LINAC Radiation Dose produces pulses with Cherenkov light
Characteristic spectrum
Cherenkov in tissue
oxygenated De-oxygenated
Cherenkovemission
Tissue phantom 1% blood +
1% Intralipid
Axelsson et al, Med. Phys. 2010Zhang et al, Med. Phys. 2012
Cherenkov spectroscopy
Linac
(Cherenkov)
pulses
Cherenkov frame
Background frame
TimeC
am
era
ga
tin
g
Ambient room light
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Time-gated Intensified Camera System
Time-gatedImage
Intensifier
CMOSCamera
FPGABoard
USB3 in/out
DISCLOSURE: B. Pogue is founder & president of DoseOptics.
Single photon imagingwith room lights on!
Petr Bruza Mike JermynVenkat Krishnaswamy Bill Ware Cedar Farwell
Linac
(Cherenkov)
pulses
Cherenkov frameBackground frame
Time
Ca
me
ra
ga
tin
g
Relay lens
FarzeenChristie
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Cameras installed in all Dartmouth Linac Rooms
AdditionalUser sites:DartmouthU PennWash UEmoryHarvard/MGH
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Verification of
beam positionon the
patient
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Cherenkov is a direct display of surface dose
Miao et al, Med. Phys. 2019
Light Field Cherenkov FILM
CherenkovFILM
Cherenkov
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Confidential DoseOptics LLC
Live Cherenkov Cumulative Cherenkov
Planned Treatment Area Planned Cumulative Surface Dose
Whole breast radiotherapy verification
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Incidents observed with Cherenkov images
Day 1
1050
‘arm down’ treatments on different days
Jarvis et al, IJROBP (in review 2020)
Day 2
Day 3 Day 4
R Hachadorian, et al,
Session:Multi-Disciplinary ePoster
Poster #: PO-GeP-M-194
Contralateralbreast
Contralateralbreast
shoulder
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Incidents observed with Cherenkov images
Day 1
104 105
Day 2
Neck involvementBolus placement differences
Jarvis et al, IJROBP (in review 2020)
R Hachadorian, et al,
Session:Multi-Disciplinary ePoster
Poster #: PO-GeP-M-194
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11/10
Match line views from Cherenkov on skin
Hachadorian et al, submitted 2020
R Hachadorian, et al
Session Title: Multi-Disciplinary ePoster
Poster #: PO-GeP-M-75
Supraclavicular field Tangent field
Match region
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Head and Neck Tumor Treatments
Planned dose
Imaged signal
Real time view of treatment
Treatment Plan
Dan Alexander
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Cherenkov ≈ Surface Dose ?
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X-ray dose builds up & Cherenkov is emitted
(b) (c)
Build up is always linear over the first 8 mm!!
𝜑𝑅 𝑧 = 𝑆(𝑧)3𝜇𝑠
/
𝜇𝑎𝑒−𝜇𝑒𝑓𝑓𝑧 S(z) = S0 (k1 + k2z)
𝜑𝐶ℎ 𝑧 =𝑆0 𝑘1
𝐷𝜇𝑒𝑓𝑓𝑒−𝜇𝑒𝑓𝑓𝑧 −
𝑆0 𝑘2
2𝐷𝜇𝑒𝑓𝑓2 (𝑒
−𝜇𝑒𝑓𝑓𝑧 − 𝑒𝜇𝑒𝑓𝑓𝑧)
Pogue et al, Proc SPIE BiOS 2020
Signal is dependent upon:• Build up rate with depth• Absorption coefficient (≈blood volume)
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Cherenkov emission is decreases with CT number!
Higher CT number ≈ higher blood vol(blood attenuates light)
IC(E) = c(CT,E) ∙ IR(E)
Blue Ribbon ePoster
Poster Number: BReP-SNAP-M-87
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I. Tendler et al, IJROBP 2020YOUNG INVESTIGATOR SYMPOSIUM
Session: MO-CD-TRACK 1-2
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AutomatedNon-contact
Dose readout
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back delivery
Stanford Technique
front delivery
T Miao & T. Zhu
Blue Ribbon ePoster
BReP-SNAP-M-141
Prof Tim Zhu UPenn
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Cumulative Dose-Rate Histogram
XY
Z
Scre
en
Spot Scanning
Radioluminescence Imaging of Proton Beam DoseDose Rate Dynamics Volumetric LET and Dose Patient Plan Imaging
Op
tic
al
Relative Dose
70 MeV 150 MeV100 MeV
M Rahman: Therapy General
ePoster PO-GeP-T-388
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Summary of observations:
• Cherenkov imaging allows real time view of delivery & incidentsneck, shoulder, contralateral, bolus, plan incidents
• Quantitative dose imaging with CT and optical corrections
• Match lines can be visualized at adjacent fields
• Absolute dose point values obtained with scintillator imaging
• Total skin electron therapy mapping is possible
• Small beam dosimetry
• Proton beam dosimetry via scintillation