feasibility of image-guided srs for trigeminal neuralgia with novalis
DESCRIPTION
Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis. Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis. Physicists (University of Arizona) RJ Hamilton CJ Watchman J Gordon NJ Stanley Radiation Oncologist (University of Arizona) B Stea - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/1.jpg)
Arizona’s First University.
Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis
![Page 2: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/2.jpg)
Physicists (University of Arizona)RJ HamiltonCJ WatchmanJ GordonNJ Stanley
Radiation Oncologist (University of Arizona)B Stea
Neurosurgeon (Center for Neurosciences, Tucson, AZ)A Sanan
Feasibility of Image-Guided SRS forTrigeminal Neuralgia with Novalis
![Page 3: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/3.jpg)
Accuracy of Frame-Based Novalis SRS for TGN
• Rahimian et al (J. Neurosurg S3 101:351-55, 2004)– Image Fusion 0.4 mm– MR 0.2 mm– Gantry 0.3 mm– Couch 0.6 mm– Overall 0.9 mm (0.6 mm w/o couch)
• Target position 0.2 mm• Laser 0.2 mm
• Phantom Radiographic Test 0.7 ± 0.1 mm
![Page 4: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/4.jpg)
Frame-Based SRS for TGN
• Human Issues– Pins fix frame to skull
– Uncomfortable during treatment delivery too
– Patient remains in department for several hours waiting for treatment
– Difficult to abort procedure (machine problems)
– Scheduling: patient, neurosurgeon, radiation oncologist, physicist, treatment time, etc…
![Page 5: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/5.jpg)
Frame-Based SRS for TGN
• Technical Issues– Frame-based systems require that the position of a
patient in the frame is unchanged from application of the pins through treatment completion
– The stereotactic frame (not the patient) is aligned with the machine isocenter for treatment
– Differential torque on the head ring deforms it
– Head ring is bolted to the table assembly, patient may be displaced relative to it.
![Page 6: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/6.jpg)
Image-Based SRS for TGN
• Human Issues
– Plastic mask (BrainLab U-PLAST mask fixation system) helps patient remain still
– Scheduling: specialists (neurosurgeon, radiation oncologist) may work at their convenience, treatment time set for patient
![Page 7: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/7.jpg)
Image-Based SRS for TGN
• Technical Issues
– Positioning accuracy • Depends on the accuracy of the registration of images
between the planning system (DRRs) and imaging system (ExacTrac)
• Depends on the calibration of the imaging system with the mechanical isocenter
– Variations of the position of the patient in the mask (stereotactic coordinate space) are not important provided that the imaging system can correct for it (ExacTrac X-Ray 6D and Robotics)
– Once positioned for treatment, the patient must remain fixed.
![Page 8: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/8.jpg)
Feasibility of Image-Based SRS for TGN
• Demonstrate System Accuracy
– Anthropomorphic Phantom Experiment
• Demonstrate that variations of the patient position in the mask are not important
– Anthropomorphic Phantom Experiment
• Confirm for each patient that deviations of their head within the mask may be corrected by the ExacTrac X-ray 6D and robotics
– Perform planning CT scan plus two addition CT scans. The final scan is performed 1 hour prior to the scheduled treatment time.
• Confirm that the patient does not move during treatment
– Repeat the ExacTrac X-ray positioning 3-4 times (every 3rd couch position) during treatment delivery
![Page 9: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/9.jpg)
Demonstrate System Accuracy
• Anthropomorphic Phantom – 0.25” BB embedded in head
– BrainLab U-PLAST mask constructed
– Axial CT scan (35 cm FOV 1.5mm slice) with BrainLab Head & Neck Localizer
– BrainScan Plan
– ExacTrac 6D X-Ray and Robotics
![Page 10: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/10.jpg)
Anthropomorphic Phantom CT
![Page 11: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/11.jpg)
Anthropomorphic Phantom CT
![Page 12: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/12.jpg)
Anthropomorphic Phantom CT
![Page 13: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/13.jpg)
Anthropomorphic Phantom Plan
![Page 14: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/14.jpg)
Accuracy of Isocenter Determination
• Two planners contoured the BB in the planning system and then placed the isocenter at the center. Repeated the procedure 10 times each.
mean stdev mean stdev difference pixel size
AP -24.93 0.19 -24.65 0.22 -0.28 0.68Lateral -30.34 0.24 -29.93 0.25 -0.41 0.68Vertical 25.09 0.01 25.24 0.10 -0.15 1.50
Planner 1 Planner 2
Isocenter Coordinate Determination
![Page 15: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/15.jpg)
Pixel SizePixel Size = 0.5 mm
![Page 16: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/16.jpg)
Pixel SizePixel Size = 0.5 mm
![Page 17: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/17.jpg)
Pixel SizePixel Size = 0.5 mm
![Page 18: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/18.jpg)
Pixel SizePixel Size = 0.5 mm
0.5 mm
![Page 19: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/19.jpg)
ExacTrac Calibration
![Page 20: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/20.jpg)
ExacTrac Calibration
![Page 21: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/21.jpg)
ExacTrac Calibration
![Page 22: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/22.jpg)
ExacTrac Calibration
![Page 23: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/23.jpg)
ExacTrac Calibration
![Page 24: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/24.jpg)
ExacTrac Calibration
![Page 25: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/25.jpg)
ExacTrac Calibration
![Page 26: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/26.jpg)
ExacTrac Calibration
![Page 27: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/27.jpg)
ExacTrac Calibration
![Page 28: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/28.jpg)
ExacTrac Calibration
![Page 29: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/29.jpg)
ExacTrac Calibration
![Page 30: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/30.jpg)
Anthropomorphic Phantom Treatment
Head Holder
![Page 31: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/31.jpg)
Anthropomorphic Phantom Treatment
![Page 32: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/32.jpg)
Anthropomorphic Phantom Treatment
Select Isocenter
![Page 33: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/33.jpg)
Anthropomorphic Phantom Treatment
Automatic Preposition
![Page 34: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/34.jpg)
Anthropomorphic Phantom Treatment
![Page 35: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/35.jpg)
Anthropomorphic Phantom Treatment
Automatic Preposition Film Verification
Difference = ( 0.3, -0.2 ) = 0.4 mm
10 mm cone
BB shadow
![Page 36: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/36.jpg)
Anthropomorphic Phantom Treatment
![Page 37: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/37.jpg)
Anthropomorphic Phantom Treatment
![Page 38: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/38.jpg)
Anthropomorphic Phantom Treatment
![Page 39: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/39.jpg)
Anthropomorphic Phantom Treatment
![Page 40: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/40.jpg)
Anthropomorphic Phantom Treatment
Film Verification
Difference = ( 0.1, 0.1 ) = 0.1 mm
10 mm cone
BB shadow
![Page 41: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/41.jpg)
Phantom Displacement Experiment
• Phantom moved by exactly 2.0 cm in all three directions as determined by a ruler
• Perform X-ray Alignment with ExacTrac
• Shifts Found by ExacTrac – AP 19.85 mm– Lateral 20.05 mm– Vertical 20.40 mm
![Page 42: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/42.jpg)
Phantom Moved: Not in Mask !!!
Head Rotated
![Page 43: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/43.jpg)
Phantom Moved: Not in Mask !!!
No Head Holder Head Lower and Rotated
Head Holder Removed
![Page 44: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/44.jpg)
Phantom Moved: Not in Mask !!!
Position using standard procedures with array
![Page 45: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/45.jpg)
Phantom Moved: Not in Mask !!!
![Page 46: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/46.jpg)
Phantom Moved: Not in Mask !!!
![Page 47: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/47.jpg)
Phantom Moved: Not in Mask !!!
![Page 48: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/48.jpg)
Phantom Moved: Not in Mask !!!
Film Verification
Difference = ( 0.1, 0.1 ) = 0.1 mm
10 mm cone
BB shadow
![Page 49: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/49.jpg)
Phantom Moved: Not in Mask !!!
Rotation too large for robotics
![Page 50: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/50.jpg)
Phantom Moved: Not in Mask !!!
![Page 51: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/51.jpg)
Uncorrected Rotations
• Isocenter position is still fine
• Uncorrected rotation changes geometry of beams relative to skull and therefore changes the calculated doses
![Page 52: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/52.jpg)
Patient Repeat CT Scans
• Original CT scan includes mask fabrication
• Second CT scan scheduled between date of original scan and treatment day
• Third CT scan obtained one hour prior to scheduled treatment time
![Page 53: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/53.jpg)
Patient Repeat CT Scans Results
• The mean observed isocenter displacements from repeat CT localizations in the mask
– AP 0.9 mm
– Lateral 0.6 mm
– Vertical 1.7 mm
![Page 54: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/54.jpg)
Patient Motion During Treatment
• ExacTrac localization was preformed during treatment every three arcs and at the end of the procedure to evaluate the extent of patient movement in the mask during treatment.
![Page 55: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/55.jpg)
Patient Motion During Treatment: Results
• The mean displacements from isocenter – AP 0.3 mm– Lateral 0.5mm– Vertical 0.3 mm
• The mean rotations were all less than 0.4 degrees.
![Page 56: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/56.jpg)
Dosimetric Effects of Isocenter Misplacement
• Five patients treated to 90 Gy at the isocenter with a 4 mm cone
• Isocenters of original plans were displaced towards the brainstem by 0.5, 1.0, 1.5, and 2.0 mm (worst case scenarios).
• Maximum brainstem and CN5 doses computed
![Page 57: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/57.jpg)
Isocenter Misplacement Results: CN5
Maximum CN5 Dose vs Isocenter Displacement Towards Brainstem
85
86
87
88
89
90
91
0 0.5 1 1.5 2
Displacement Towards Brainstem (mm)
Do
se (G
y)
P1
P2
P3
P4
P5
![Page 58: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/58.jpg)
Isocenter Misplacement Results: Brainstem
Maximum Brainstem Dose vs Isocenter Displacement Towards Brainstem
0
30
60
0 0.5 1 1.5 2
Displacement Towards Brainstem (mm)
Do
se
(G
y)
P1
P2
P3
P4
P5
![Page 59: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/59.jpg)
Conclusions
• Accuracy is better than image pixel size
• Mask reproducibility allows accurate positioning with ExacTrac 6D and Robotics
• Patients move minimally during treatment. Monitoring the position adds little to the overall treatment time and insures accuracy
• Patients tolerate the procedure well and have not experienced complications
![Page 60: Feasibility of Image-Guided SRS for Trigeminal Neuralgia with Novalis](https://reader036.vdocuments.mx/reader036/viewer/2022062500/568152ba550346895dc0dbc3/html5/thumbnails/60.jpg)
Thank You!