clinical experience with incise™ mlc: a new cyberknife ... · prostate 45 fx- 81.0 gy example...
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Clinical Experience with InCise™ MLC:
A New CyberKnife® Multileaf Collimator
Tewfik Bichay, PhD, ABMP
Director of Medical Physics
Mercy Health, Saint Mary’s
Grand Rapids, MI, USA
Physicist: Chen Chen
Resident: Alan Mayville
Physician: Gil Padula
Therapists: Stewart Davis
Monica Patton
Disclaimer:
• “The views expressed in this presentation are those of the presenters
and do not necessarily reflect the views or policies of Accuray
Incorporated or its subsidiaries. No official endorsement by Accuray
Incorporated or any of its subsidiaries of any vendor, products or
services contained in this presentation is intended or should be
inferred.”
Disclaimer
Disclosure:
• Partial financial support by Accuray Incorporated
Disclosure
Mercy Health
Grand Rapids
San Antonio
Outline: CyberKnife® M6™System-InCise™ MLC
• InCise™ MLC Configuration
– Overall design, field size
• Tests Performed
– Commissioning
– Testing, E2E, AQA, etc.
– Dosimetric validation
• Clinical Results
– Comparison of Fixed/IrisTM with MLC for clinical cases
• Discussion
Outline
Introduction: CyberKnife® Conventional Collimators
• Two Current Configurations
– Fixed
5 mm-60 mm, 5,7.5,10,12.5,15,20,25,30,35,40,50,
and 60 mm
Either automatic (G4) or manual (M6™)
replacement
Current Cyberknife
• Two Current Configurations
– Fixed
5 mm-60 mm, 5,7.5,10,12.5,15,20,25,30,35,40,50,
and 60 mm
Either automatic (G4) or manual (M6) replacement
– Iris™
5 mm-60 mm, 5,7.5,10,12.5,15,20,25,30,35,40,50,
and 60 mm
Automatic diaghragm
Only 10% of beams allowed at 5 mm and 7.5 mm
Current Cyberknife
What does this mean?
Introduction: CyberKnife® Conventional Collimators
Introduction: CyberKnife® Collimators
Cyberknife Collimators
Simple
Fixed
Complex
MLC
Intermediate
Iris™
Introduction: CyberKnife® M6™System-MLC
•Phase 1: M6™ Program “Go Live” June 2014
– Fixed and Iris™ collimators only
– Clinical experience: cranium, lung, prostate, spine, liver
•Phase 2: InCise™ MLC commissioning October 2014
– Non-clinical MLC validation agreement with Accuray
•Phase 3: Testing Nov 2014-January 2015
– Goal was to carry out hundreds of tests during “extreme”
treatments
Introduction
Introduction: CyberKnife® M6™System-MLC
•Phase 4: MLC “Go Live” March 2, 2015
– Lacks Cancer Center treated 2nd patient
– Current experience: Cranium, prostate, spine, liver
Introduction
501044.B
INCISE™ MULTILEAF COLLIMATOR (MLC) OVERVIEW Field Size: 10.0cm x 12.0cm*(10 x 10)
82 tungsten leaves (41 leaf pairs)
Full leaf inter-digitation
Full leaf over-travel
Single focus MLC
• 2.5mm thickness*
• 90.0mm leaf height
• 0.5mm leaf positioning accuracy*
• 0.2mm mechanical reproducibility
* = Manufacturers specification at 800mm SAD
MLC Overview
MLC overview
•Leaves tilted through 0.5°
Tool plate Patient-plane shield
Fixed Tungsten side-plates
MLC Overview
501044.B
HOW INCISE™ MLC TREATMENTS WORK Every treatment consists of multiple, individually targeted, non-isocentric, non-coplanar beams
Each beam may consist of one or more MLC segments
Dose shaping and modulation achieved by step-and-shoot process
• Each unique robot position and tumor intersect point = 1 beam
• Each unique MLC shape = 1 segment
MLC Overview
MLC Overview
MLC Overview
MLC Overview
MLC Overview
SCD = 400mm
30mm
30mm
30mm Angled 4.30 to vertical
MLC overview: 3-sided design
MLC Overview
MLC Overview
CyberKnife® M6™ System Tests Performed
MLC Tests
Test Number
Commissioning 1
Initialization 65
Laser Alignment 65
Picket Fence 65
AQA 65
Garden Fence 26
E2E 3
Beam Data Spot Check 3
Leakage Test (film/chamber) 3
Patient QA (Dosimetric) 11
Non-Dosimetric Delivery 50
End to End (E2E) Test
MLC Tests
End To End (E2E) Test
MLC Tests
AQA Test
MLC Tests
Commissioning Profiles
0
10
20
30
40
50
60
70
80
90
100
-100 -80 -60 -40 -20 0 20 40 60 80 100
Off Axis Distance (mm)
7.5-Y
52.5-Y
97.5-Y
MLC Tests
Results: CyberKnife® M6™ System Garden Fence
Mean Error
Date X1 X2 Pass?
mm mm Y/N
1 0.04010 -0.00168 YES
2 -0.10800 -0.26700 YES
3 -0.17400 -0.40100 YES
4 0.00873 -0.16600 YES
5 -0.02850 -0.24400 YES
6 0.10100 -0.12600 YES
7 0.15400 -0.10500 YES
8 0.01390 -0.16600 YES
9 -0.01240 -0.21800 YES
10 0.01890 -0.21500 YES
11 -0.01390 -0.22500 YES
12 -0.15900 -0.04320 YES
13 -0.22900 -0.11400 YES
14 -0.10300 -0.02270 YES
15 -0.02540 0.09640 YES
16 -0.17000 -0.06250 YES
17 0.02330 0.03670 YES
18 -0.01910 -0.21300 YES
19 -0.06410 -0.18900 YES
20 -0.06490 -0.21200 YES
21 -0.08450 -0.19400 YES
22 0.20300 0.03780 YES
23 0.03250 -0.06500 YES
24 0.17300 0.04400 YES
25 0.05660 -0.02000 YES
26 0.08960 -0.02100 YES
MLC Tests
Cranial 1 Fx- 18.0 Gy example
Planning Examples
Cranial 5 Fx- 25.0 Gy example
Planning Examples
Cranial 5 Fx- 25.0 Gy example
Planning Examples
Prostate 5 Fx- 36.25 Gy example
Planning Examples
Prostate 5 Fx- 36.25 Gy example
Planning Examples
Prostate 5 Fx- 36.25 Gy example
Planning Examples
Liver 5 Fx- 33.0 Gy example
Planning Examples
Spine 1 Fx- 16.0 Gy example
Planning Examples
Spine 1 Fx- 16.0 Gy example
Planning Examples
Spine 1 Fx- 16.0 Gy example
Planning Examples
Cranial 25 Fx- 50.4 Gy example
Planning Examples
Prostate 45 Fx- 81.0 Gy example
Planning Examples
Examples of Prostate, Cranium and Spine
Planning Summary
Patient Site %Norm Vol Dose Min Mean Max Body
Integral CI %Cov-1 %Cov-2 Bladder Rectum Time Beams
PTV Rx Mean % vol covered by Rx mean Mean
mm3 cGy cGy cGy cGy cGy PTV CTV cGy cGy min
CA Iris Prostate 78 71360 3625 2792 4146 4647 256 1.11 96.1 99.4 1135 1015 40 235
MLC 82 3012 4045 4421 121 1.21 96 100 831 1149 25 50
52.7% 37.5% 78.7%
Bladder Rectum
DA Iris Prostate 74 118617 3625 3327 4201 4899 396.6 1.13 95.7 99.8 2623 1569 26 139
MLC 74 2635 4302 4899 269.1 1.15 94.6 99.9 2040 1224 18 40
32.1% 30.8% 71.2%
Bladder Rectum
MA Iris Prostate 77 97781 3625 3241 4159 4708 256.4 1.08 95.6 95.9 2760 1521 33 151
MLC 79 3066 4036 4589 197.2 1.10 94.6 99.5 2616 1433 24 64
23.1% 27.3% 57.6%
Bladder Rectum
WI Iris Prostate 85 162400 8100 7501 8656 9529 812.5 1.15 96.4 98.8 4956 4566 44 336
MLC 87 7435 8634 9529 514.5 1.16 94.8 99.9 3425 3824 22 137
36.7% 50.0% 59.2%
Wbrain Bstem Opath
HE Iris Cranium 77 24968 2500 1918 2891 3247 288.3 1.11 95.2 99.8 52.7 104.7 29 135
MLC 86 2160 2660 2941 306.8 1.19 96.6 99.9 152.5 184.8 20 42
-6.4% 31.0% 68.9%
Bstem Opath
PI Iris Cranium 80 11712 2500 2296 2741 3125 114.8 1.47 94.8 98.8 127.5 52.1 21 88
MLC 81 2187 2730 3086 89.7 1.53 95.3 98.3 102.5 131.7 18 17
21.9% 14.3% 80.7%
Bstem Opath
BR Iris Cranium 75 39646 2500 1818 2864 3333 166 1.18 95.5 98.4 139.4 37.9 40 143
MLC 77 2060 2786 3247 157.9 1.30 97.2 97.5 190.5 73.8 27 51
4.9% 32.5% 64.3%
Cord Cord+5mm
BE Iris Spine 77 20142 1600 815 1839 2078 53.8 2.16 89.4 na 391 474 38 131
MLC 77 995 1923 2222 36.9 1.86 90.6 na 503 594 32 55
31.4% 15.8% 58.0%
Summary of Prostate, Cranium and Spine
Planning Summary
CI PTV (%) CTV (%) Body (cGy) T (min) Beams (#)
Iris 1.30 94.8 98.7 293.1 33.9 169.8
MLC 1.31 95.0 99.3 211.6 23.3 57.0
Reduction 27.8% 31.4% 66.4%
ID Time
(min) Volume
PTV
(cc)
Nodes Beams Segments Mean
Dose
(cGy)
Measured
(cGy) Difference
(%)
1 17 112.2_ 35 40 69 1391.77 1401.06 0.67%
2 15 23.6 31 31 35 1527.31 1539.14 0.77%
3 23 23.8 49 55 86 620.76 619.16 -0.26%
4 26 11.2 61 61 73 1570.52 1576.48 0.38%
5 19 16.0 26 26 53 1506.5 1513.6 0.47%
6 22 60.6 60 101 122 1430.67 1444.64 0.98%
7 27 112.5_ 56 56 150 1457.49 1471.17 0.94%
8 18 51.5 39 39 67 1368.59 1388.89 1.48%
9 41 89.1 50 50 167 2685.77 2695.88 0.38%
10 20 12.7 40 40 68 487.92 502.87 3.06%
Mean 22.8 51.3 44.7 49.9 89 1405 1415 0.89%
Dosimetric Validation
Dosimetric Validation
Conclusion
•Evaluation demonstrated that the MLC is a reliable device,
capable of accurate treatments – No modifications were required
•The second patient treatment worldwide utilizing the
CyberKnife® MLC was at Lacks Cancer Center on
March 2, 2015 – Approx 25 patients planned, and 15 treated with MLC
Cranial, Prostate, Spine, Liver
•Benefits of MLC compared to Iris™/Fixed: – Approximately 30% faster treatment
– Integral dose reduced by 28% (over a limited volume)
– Number of beams reduced by 66%
Conclusion
Discussion
CK-MLC Discussion