igrt perspectives
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Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Perspectives Perspectives on IGRTon IGRT
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Our Panel
AJ Mundt, MD
Professor & ChairMegan Gannaway, BS
Radiation Therapist
Mickey Goldman, MHA
Business Director Todd Pawlicki, PhD
Physics Director
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
The Department
• Equipment, Trilogy (up to 40/day)• Where we are going – Vision • What we currently do with IGRT
kV/kVCBCT
SetupTreatment monitoring
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
IGRT A Physician’s Perspective
• A long overdue technology• Known for years that….
Patients are difficult to setupTargets change in position between (inter-fraction) and during (intra-fraction) treatmentsTumors and patients change over the treatment course
• Increasingly aware that such factors effect the quality and delivery of treatment
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
De Crevoisier et al. (MDAH)Int J Radiat Oncol Biol Phys (2005)
• Impact of rectal distension at simulation on outcome of prostate pts
• Distension correlated with PSA control
• Emphasized need for daily prostate localization with IGRT
Wake Up Call
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
What is IGRT?
• Difficult question to answer• Image-guided RT (IGRT) means different
things to different people• No consensus exists• Some define IGRT very broadly, some
define it very narrowly• Most don’t define it at all
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
RTOG Research Plan 2002-2006IGRT Committee ReportMichalski J, Purdy JA, Gaspar L, et al.
Int J Radiat Oncol Biol Phys 2001;51:60-5
“IGRT refers broadly to treatment delivery using modern imaging methods, such as CT, MRI, PET and Ultrasound, in target and non-target structures and in RT definition, design and delivery…”
“IGRT includes, but is not limited to, 3DCRT, IMRT, stereotactic radiosurgery, stereotactic RT, and brachytherapy….”
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
What is IGRT?
• Prefer a more focused definition• Distinguish between
Image-based RT (use of imaging to define the target and normal tissues for treatment planning)Image-guided RT (use of imaging to monitor and modify treatment)
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Physician Perspective
• Use of imaging to monitor and modify treatment delivery is not new
• Various IGRT approaches have been used for decades (EPID, ultrasound, video, etc.)
• What is new is modern IGRT approaches take advantage of more frequent and sophisticated imaging techniques to localize the target with even greater accuracy
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Current IGRT Technologies
Ultrasound Video-Based Planar X-Ray VolumetricBAT Video Subtraction EPID In-Room CTSonArray Photogrammetry CyberKnife FOCAL, MSKCCI-Beam AlignRT Novalis CT-on-RailsRestitu Real-Time Video- RTRT Primaton
Guided IMRT Gantry-Mounted Varian ExaCTProtoype Tomotherapy
Tohoku, IRIS MV Cone Beam CT Commercial Siemens
Varian OBI kV Cone Beam CTElekta Synergy Mobile C-arm
Varian OBIElekta SynergySiemens In-Line
Related TechnologiesRPM gating/4DCTOptical-guided Approaches
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
• New Department• New Cancer Center• New Staff
Chair, MDs, Physicists, RTTs, Administrators, etc
• New Varian LinacsIncluding a Trilogy
• “Ideal setting” for implementing new technologies
UCSD
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Many Other Changes…• Large ↑ in daily census requiring addition of
new vaults and linacs• Busy SRS programs (brain, spine, and
body) using the frameless Trilogy system• ↑ Volume of labor-intensive techniques:
IMRT, pediatrics, brachytherapy, etc.• Opening of satellites• Transition to Paperless Department
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
IGRT at UCSD• Elected to do a staged implementation• Initially focused on planar (kV) IGRT
Anatomy-based (various sites)Fiducial (seed)-based (prostate cancer)
• Straight-forward, less time-intensive • Now introducing volumetric (CBCT) IGRT
Predominantly prostate pts without seedsOther selected sites
• Plan to ↑ CBCT use, introduce 4DCT/gating and, in future, adaptive RT
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
IGRT at UCSD• Majority of IGRT cases
Prostate CA with kV planar IGRT & fiducials• Involve the referring urologists
Seed placement (2 laterally, 1 apex)Foster a team approach
• Simulate 1 week after seed placement• Do not place seeds and simulate until after
neoadjuvant hormonal therapy• Develop a Process Flow
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Process FlowPlanar IGRT (Prostate Cancer)
Day 1MD and RTTs meet at console
Discuss seed positions, alignments and couch shifts
Day 2 thru Completion
All shifts ≤ 1 mm LR shift > 5 mmSI or AP shift > 15 mm
Seeds drift
Other shifts
Make no shiftsand treat Call MD
Make all shiftsand treat
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Prostate Seed MatchingProstate Seed Matching
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Process FlowVolumetric IGRT (Prostate Cancer)
Day 1MD and RTTs meet at console
Identify mid-prostate images (axial, sagittal, coronal) and shifts
Day 2 thru Completion
All shifts ≤ 1 mm LR shift > 5 mmSI or AP shift > 15 mmDifficulty interpreting
anatomy
Other shifts
Make no shiftsand treat
Call MD
Make all shiftsand treat
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Volumetric kV CBCT Images
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Gynecology
• Another potentially important IGRT site
• All gynecology pts at UCSD treated with IGRT
• Highly conformal IMRT plans make IGRT important
Notoriously difficult to setup patients
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Gynecology• IGRT also crucial since
we are trying to spare the pelvic bone marrow
• Difficult since it is important to reduce the low receiving low doses (V10 and V20)
• All gynecology pts thus undergo on-line kV IGRT setup (boney matching)
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Gynecologic IG-IMRT
• To evaluate the benefit of volumetric IGRT approaches in gynecology, a CBCT is also obtained daily
• Unlike kV imaging, it is obtained post-RT and analyzed off-line
• Ensure target coverage and evaluate impact of re-planning (adaptation)
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Process FlowIGRT (Gynecology)
Day 1MD and RTTs meet at console
Discuss anatomy and shifts
Day 2 thru Completion
All shifts ≤ 1 mm Any Shift > 10 mm Other shifts
Make no shiftsand treat
Call MD Make all shiftsand treat
CBCT
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Gynecologic IGRT
• CBCT will eventually replace planar kV imaging for setup evaluation
• CBCT will also be used for adaptive treatment planning
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Bladder
Rectum
Tumor
Bladder
Tumor
Rectum
PrescriptionIsodoseWeek 1 Week 3
TumorsShrink
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
• 14 cervical cancer pts undergoing RT• MRI before RT and after 30 Gy• Used to generate 2 IMRT plans• Assessed impact of re-planning on
target coverage and normal tissue sparing
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
• GTV decreases on average by 46%• Re-planning improved rectal sparing• If >30cc GTV reduction, re-planning also
improved sparing of the small bowel
Pre-RT 30 Gy
GTV
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Currently use CBCT for daily setup and adaptive RT in re-irradiation patients56 yr old stage IIIB cervical cancer pt56 yr old stage IIIB cervical cancer ptRecurs 3 yrs following definitive chemoradiotherapyRecurs 3 yrs following definitive chemoradiotherapyIsolated recurrence in PA node at L4Isolated recurrence in PA node at L4--L5 (L5 (½½ in old field)in old field)IMRT 59.4 Gy in 1.8 Gy fractions plus CDDPIMRT 59.4 Gy in 1.8 Gy fractions plus CDDP
Excellent palliative response, minimal toxicityExcellent palliative response, minimal toxicity
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
IGRT A Physicist’s Perspective
• Image-guided radiotherapy is being overvalued as a clinical tool in radiation therapy
• Presented as a Point/CounterpointMed Phys (33) Oct 2006Howard I. Amols, Ph.D.David A. Jaffray, Ph.D.
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
IGRT in Radiotherapy
0.0
0.2
0.4
0.6
0.8
40.0 50.0 60.0 70.0 80.0
Dose (Gy)
0.00
0.05
0.10
0.15
0.20RT Failure Function (F)Quality Distribution
Expected Failures E<F>
Figure 2
F = 1 − [TCP·(1−NTCP)]
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
IGRT in Radiotherapy
0.0%
2.0%
4.0%
6.0%
8.0%
10.0%
12.0%
14.0%
16.0%
18.0%
-6.0% -4.0% -2.0% 0.0% 2.0% 4.0% 6.0% 8.0%
Per cent deviation from prescription dose
Expe
cted
radi
othe
rapy
failu
re
0.5Gy SD1.0Gy SD2.0Gy SD3.0Gy SD4.0Gy SD
Figure 3
0.5 σ
4.0 σ
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
IGRT in Radiotherapy
• Theoretical evidence – Improving quality and precision may increase survival and decrease complications
• 1988 Publication – Effects of dosimetric and clinical uncertainty on complication-free local tumor control
Boyer AL, Schultheiss T. Radiother Oncol. 1988 Jan;11(1):65-71.
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
IGRT A Physicist’s Perspective
• How can one use IGRT today?Precise and accurate imagingTreatment monitoring
• Quality AssuranceWhat and how?
• Training on image interpretation • What is exciting about IGRT for physics?
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Daily Prostate Localization
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Treatment Monitoring
• Easy to import into Eclipse
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
OBI Clinac HW ModificationsSupervisor
GeneratorIn 480 VOut 125kV
Auxiliary electronicsCarousel cntrlGantry encoder
kV HV cable takeupIAS3 DU A-to-DPower shelf
MV Detector
Exact Arm
Laser GuardMtn
CntrlRack
RPM Gating Camera
SRS/SRT 6x filter
SRS Collimator
X1/X2 CollSPRO
Lat, Long, VrtSPRO
Rotation SPRO
kV Source
kV Detector
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
IGRT QAThings to consider when implementing IGRT
• Safety and functionality• MV/kV isocenter coincidence• Geometrical accuracy (arm position)• Shift calculation (MV/kV, kV/kV, CBCT)• OBI isocenter vs gantry angle• Image quality (kV, CBCT)• CBCT image uniformity• CBCT HU constancy
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
QA on the Trilogy• Safety and functionality• MV/kV isocenter coincidence• Geometrical accuracy (arm position)• Shift calculation (MV/kV, kV/kV, CBCT)• OBI isocenter vs gantry angle• Image quality (kV, CBCT)• CBCT image uniformity• CBCT HU constancy
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
kV/MV Isocenter Coincidence
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
kV/MV Isocenter Coincidence
Sua Yoo et al. A quality assurance program for the on-board imager.Accepted for publication in Med Phys.
Collaborative effort: Duke, Emory, Henry Ford, Stanford, and Varian
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
IGRT Is Not Done Evolving
Picture courtesy of Steve Jiang, PhD; MGH
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
IGRT A Therapist’s Perspective
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
How kV/kV impacts the schedule
• Until staff is comfortableSchedule half hour for kV/kV matching
• Evaluating the images takes time• After a few months
kV/kV matching only adds about 5 min to a patients total treatment time
• Comfort with the softwareHardware takes 2-3 months for each therapist
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
How CBCT impacts the schedule
• 45 min time slots until staff is comfortable
• 30 min schedule for CBCT patients
• Some patients are CBCT once a week, some daily
• Patients must be able to hold still at least 30 min
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
A typical day on the TrilogykV/kV
Anatomy40%
non-IGRT15%
CBCT Prostate
19%
CBCT Other
6%
kV/kV Seeds20%
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
How do we use kV/kV
• Manually match• Fiducials for prostate• Bony anatomy
PelvisHead and neckThorax (though this is more difficult)Any difficult setup
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
How do we use CBCT
• Prostate without fiducialsManually match the borders of the prostate with the contours from Eclipse
• Other selected patients (GYN, etc.)
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
What patients think about kV/kV
• Patients are curious • Patients request kV/kV• Patients are rarely concerned about the
length of time on the table• Patients are reluctant to be treated
without kV/kV
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
What patients think about CBCT
• Patients initially unhappy about time on treatment table
• Once patients understand CBCT More than happy to be on the table for 30 min
• Prostate patients with a full bladder are sometimes uncomfortable
• Non-compliant patients might not be great candidates
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Difficulties with kV/kV and CBCT
• Considerable training is needed• Interaction between software programs
Troubleshooting errors • Evaluating images can be difficult • Spending less time with the patients
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
What do RTTs like about kV/kV
• Effective and reproducibleInternal anatomy or seeds are localized daily
• Less “chasing” external marks• Easy to analyze with training• Time efficient
15 min time slot possible
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
What do RTTs like about CBCT
• It’s interesting technologyImagingAnatomyQA
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
QA for kV/kV and CBCT
• Daily warm-upkV source must be warmedCoincidence check between kV and MV
• Practice, practice, practiceCBCT a phantom early on to practice:
Hardware and software usage
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
In a perfect world…
• Set up an IGRT protocol before clinical routine clinical use
Cases/Sites, imaging frequency, procedures, thresholds, etc.
• Physicians – Please educate RTTs on image interpretation
• Physicists – Please be near by to troubleshoot problems
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Where’s the BEEF?!
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
A Business PerspectiveA Business Perspective
• Goal is to differentiate yourself in the marketplaceImage guided therapies are becoming the new standard of care
• Clinical Program Development• Educate referring physicians
Most significant impact• Public education
Website design• Advertising
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Determine impact on the business• New equipment or upgrade to existing
technology?• Determine implications on existing capacity
Do we have excess capacity?How will we accommodate increased treatment time?
• What will be the impact on the treatment schedule?
• Training issues
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Prepare the business• Billing setup
Update hospital charge masterUpdate Varis/Aria procedure detail masterCheck interface to ensure information is being transmitted and accepted accuratelyEducate billing & collection staff of new procedure codes
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Reimbursement Issues• On Board Imaging (OBI) - 77421
Stereoscopic x-ray guidance for localization of target volume for the delivery of radiation therapy – used for positioning of the patient
Must use kV or MV x-rays onlyHas both a technical and professional componentAPC 1502 – payment rate $75.00
2007 proposed change to APC 0257 & payment reduction to $60.14
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Reimbursement IssuesReimbursement Issues• Cone beam CT (CBCT) – 76370
Computed tomography for placement of radiation therapy fields – use for daily CT for planning.Technical charge only – for both hospitals and freestanding centersMust have case by case orders from the MD as to why the procedure is being done and frequency of useAPC 0282 - $94.82
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Source – James Hugh III- AMAC
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Website
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
AdvertisingAdvertising• Newspaper• Billboards• Advertorials• Brochures• Radio• Television
AdsHealth related talk shows
Varian Users Meeting at ASTRO 2006November 4th, 2006. Philadelphia, PA
Perspectives Perspectives on IGRTon IGRT
QUESTIONS??