kv-& mv-cbct imaging for daily localization: · pdf filemoyed miften, phd. dept of...
TRANSCRIPT
![Page 1: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/1.jpg)
Moyed Miften, PhDDept of Radiation Oncology
University of Colorado Denver
kV-& MV-CBCT Imaging for Daily Localization: Commissioning, QA,
Clinical Use, & Limitations
![Page 2: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/2.jpg)
Questions• Disease Stage (local, regional, metastatic)• Tumor location• Edge of the tumor volume• Nodes involvement• Tumor within Rx fields
– Respiratory Motion• OARs location• Modulate the intensity to maximize the
therapeutic ratio
![Page 3: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/3.jpg)
In-Room Imaging Technologies
CT on rails2D kV Imaging
kV CB ImagingkV & MV CB Imaging
kV CB Imaging MV-CT Imaging
![Page 4: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/4.jpg)
Mega-Voltage CBCT• MV-CBCT features & characteristics• The image quality vs. exposure challenge…• … and an elegant workaround• MV-CBCT as a localization system• Thinking outside the box• QA• Clinical experience• Conclusions
![Page 5: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/5.jpg)
MV-CBCT Basics
3, 5, 8, 10, 12, & 15 MU delivery protocols(0.01-0.1 MU per projection)
270o
110o
![Page 6: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/6.jpg)
Features of MV-CBCT• Volumetric patient image using a 6x beam• High sensitivity a-Si panel• Synchronization of beam pulse & panel read
out • Gantry rotation of 200 degrees • Time: acquisition ~ 50 sec & recon. ~ 1 min• 27 cm3 max FOV (FS 27.4 x 27.4 cm & SID
@ 145 cm)• Slice thickness range: 1 mm to 5 mm• CT image sizes: 1282, 2562 or 5122 pixels• Dose delivered 3 cGy – 12 cGy
![Page 7: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/7.jpg)
MV-CBCT ConfigurationCB Protocol Name
MUs (1-200)4, 10, 15 MU
Slice Size: 128x128, 256x256, 512x512
Slice Thickness0.5 to 10 mm
Reconstructing Kernel:Smoothing,
Smoothing H&N,Smoothing pelvis
![Page 8: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/8.jpg)
MV-CBCT Localization
Reconstruction
RegistrationTable offsets
4-6 minutes
Acquisition
An Integrated System
![Page 9: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/9.jpg)
Image Contrast vs. Exposure
Image Quality Phantom
![Page 10: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/10.jpg)
CNR vs. Dose for 7 MU Protocols and 3 Materials
0 10 20 30 40 50 600
2
4
6
8
10
Dose (cGy)
CN
R
ρ = 1.5
ρ = 1.2
ρ = 1.09
35%
15%
CNR ~ √dose
![Page 11: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/11.jpg)
Resolution vs. Exposure
• Smallest visible bar group was 0.3 lp/mm for the 3 & 5 MU protocols
• 0.4 lp/mm for all other protocols. • kV-CT was 0.6 lp/mm
kV-CT MV-CBCT
12 cGY
![Page 12: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/12.jpg)
Improved Contrast & Resolution at Higher Doses But…
2.5 cGy 9 cGy
Better Soft Tissue Contrast
Sufficient bony anatomy at 2.5 cGy
kV-CT MV-CBCT MV-CBCT
Bony Structures
![Page 13: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/13.jpg)
Week 1 Week 2 Week 3 Week 4
Patient Imaged w/ 10 cGy
![Page 14: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/14.jpg)
Dose Verification & Simulation
TLD Measurements
Chamber Measurements
Phantom Diam.
16 cm 32 cm
MU Protocol
10 MU 15 MU
Method Meas Calc Meas CalcIsocenter 7.9 8.1 9.2 9.3
0o 10.3 10.2 12.1 11.690o 8.9 8.7 9.7 9.5180o 6.9 7.1 4.1 4.1270o 8.3 8.3 8.2 8.1
Measurements and calculations are within 0.5 cGy
Gayou, Parda, Johnson, and Miften, Med Phys 34, 499-506 (2007)
![Page 15: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/15.jpg)
Imaging CB Dose Distributions
15 MU Protocol
1614
12108
64
Dose in cGy
Model the CB imaging beam as an arc beam
![Page 16: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/16.jpg)
IMRT Incorporating Dose from MV-CBCT
77.4 60 40 20 10 5 GyPlan with CB
Plan without CB
![Page 17: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/17.jpg)
DVHs w & w/o MV-CBCTIMRT Plan w/o CB IMRT Plan w/CB
Patient A Patient BMiften, Gayou, Reitz, et al, Med Phys 34, 3760-3766 (2007)
![Page 18: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/18.jpg)
US vs. MV-CBCT vs. FM for Prostate
US: 696 couch alignments for 19 patients
CBCT: 598 couch alignments for 17 patients
FM: 393 couch alignments for 12 patients
![Page 19: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/19.jpg)
US vs. MV-CBCT vs. FM for Prostate
US
CB
FM
![Page 20: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/20.jpg)
Shift Histogram Distribution
US MV-CBCT FM
![Page 21: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/21.jpg)
Prostate Systematic & Random Errors
Localization method
AP (mm) LR (mm) SI (mm)
US -1.0 ± 5.9 -1.2 ± 6.8 -2.8 ± 5.1
MV-CBCT -0.3 ± 3.9 1.0 ± 3.9 -1.3 ± 2.5
FM 0.5 ± 4.1 -1.0 ± 3.4 0.0 ± 3.4
![Page 22: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/22.jpg)
Percentage of Shifts Greater than 5 mm
Localization Method
AP LR SI
US 38% 34% 31%MV-CBCT 16% 18% 6%
FM 20% 14% 10%
van-Herk formula: M=2.5Σ+0.7σ
Prostate PTV Margins
US data: 12.4 mmCB data: 8.2 mmFM data: 8.5 mm
Gayou and Miften, Med Phys 35, 531-538 (2007)
![Page 23: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/23.jpg)
MV-CBCT: Ave Scan Over Time
• NSCLC, right Upper Lobe, Stage IIIA T2 N2 M0• MV-CBCT well suited for localization of tumor,
but does NOT show tumor motion
CT MV-CBCT
![Page 24: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/24.jpg)
Checking Motion MV-Cine
1 cm peripheral lung massPatient treated w/3DCRT
5 cm lung massPTV Margin: 5mm, 10mmPatient treated w/ IMRT
Motion in LR, AP, & SI can be seen
Reitz, Gayou, Parda, and Miften PMB 53, 823-836 (2007)
![Page 25: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/25.jpg)
Procedure Daily Monthly 2x/yr Device
Position calibration PI, reticuleGain calibration PI
Dead pixel map PIEPID image quality Vegas, PIPSproHorizontal pos. accuracy PI, reticuleVertical pos. accuracy RulerGeometry calibration George phantomCB gain calibration CB 15, 60 MU3D image quality Ema phantomReconstr. & Registration Ema phantomDose Ion chamber
QA Procedures & Frequency
Gayou and Miften, Med Phys 34, 3183-3192 (2007)
![Page 26: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/26.jpg)
Which Patients Should be Imaged with CB?• Tumors adjacent to critical structures• Tumors prone to inter-fractional motion• Tumors with intra-fractional motion-
(Preference: 4-D planning)• Tumors prone to deformation• Compliant patients
![Page 27: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/27.jpg)
CBCT: Clinical Responsibilities• Physician
Determine clinical indication(s)Order CBCTDetermine frequency Review images (day 1, twice/weeks, daily??)Define primary ROI for physicist/therapistDefine set up parametersReview daily shifts
![Page 28: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/28.jpg)
• Physicist-- Available to review images & shifts daily - QA, calibration, output, image quality…etc
• Dosimetrist –- Dose compensation or incorporation
• Therapist -- Review images - Make appropriate table shifts
CBCT: Clinical Responsibilities
![Page 29: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/29.jpg)
Ordering a CB for a Patient
Daily, twice/wk, weekly
Soft-tissue or bony anatomy
Imaging protocol4 MU or 8-15 MU
Physician by machine console for 1st Rx
Frequency
Registration
Exposure
Review & Thresholds
Physician
Physician
PhysicistTherapist
Physicist
![Page 30: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/30.jpg)
Workflow: Physician EMR Order
![Page 31: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/31.jpg)
• Therapist oversight and competencies • Hybrid imaging schedules• Improve immobilization and patient
marking processes• Additional CBCT devices are needed to
handle clinical needs• Use CBCT to implement more
sophisticated ART techniques• Decrease PTV• Improve clinical outcomes
IGRT at the Clinic Practice Level
![Page 32: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/32.jpg)
Conclusions• MVision is a viable tool for treatment
localization
• Observed inter-fractional variations are patient specific and site-dependent
• Application of MV-CBCT for daily localization with good-image quality
• Application of MV-CBCT for verification of intra-fractional motion immediately prior to Tx
![Page 33: kV-& MV-CBCT Imaging for Daily Localization: · PDF fileMoyed Miften, PhD. Dept of Radiation Oncology. University of Colorado Denver . kV-& MV-CBCT Imaging for Daily Localization:](https://reader031.vdocuments.us/reader031/viewer/2022030403/5a7944427f8b9af91c8c2e32/html5/thumbnails/33.jpg)
Acknowledgment
UC DenverAnschutz Medical Campus
Olivier Gayou, PhDBodo Reitz, PhDQuentin Diot, PhDTeam at Allegheny General HospitalTeam at Univ. of Colorado HospitalSiemens Medical Solutions Hospital