2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 1
LA TC - 4D CON SISTEMIDI TRACKING OTTICO DI
SUPERFICIE
G.Guidi, L.Binotti, L.Morini, E.Cenacchi, T.CostiMedical Physics Dpt.
M.Amadori, P.Antognoni, M.Parmiggiani, P.Giacobazzi, G.Tolento, F.Bertoni
U.O. Radiation Oncology
Azienda Ospedaliero - Universitaria di Modena - Policlinico
Gabriele GuidiMedical Physics Dpt.Az.Ospedaliero-Universitaria di ModenaEmail: [email protected]: +39 059 422 5699 – ext. 4270
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 2
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4DCT AND GATING/TRACKING DEVICES(TOSHIBA + VISION RT)
Advantages:4DCT Exams (10 CT Dataset – 0-100% Breathing Phases): Very Fast (few minutes) – Retrospective ModeRange Slice thickness for our RT: 0.5 - 3 mm (5mm used for Cranio Spinal Irradiation and TBI)VisionRT detect capability: 1mm of the couch movement (VisionRT can appreciate the ramp up of the couch during the CT scan)Issues:4DCT Images Reconstruction (>1000 Images – 10 CT Datasets – 5/6 Hours of reconstruction)Thickness 0.5mm could be useful for Radiosurgery but few dose problem must be considered during the planning calculationTroubles and investigation:Mismatch image reconstruction due to the couch ramp-up and the breathing signal (Sinogramma Editing in develop by Toshiba)
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 3
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HELICAL PITCH AND COUCH VELOCITY (RAMP EFFECT)
12
34
56
10.5
50
10.5
100
10.5
150
10.5
200
10.5
250
10.5
300
0
50
100
150
200
250
300
Ram
p (m
m)
Ramp vs. Scan Dimension(Breathing 15_4)
Ramp Scan Dimension
CT
Ramp (Couch Acceleration)
Scan Dimension(Constant Velocity)
May be in some other CT the ramp is inside the scan packet and you could not be able to see the effect of the ramp up during the image reconstruction or have “invisible” effect on the
images...Why do I have a different velocity between VisionRT and Toshiba?
VisionRT Couch Velocity (mm/sec) vs. Breathing
0
1
2
3
4
5
6
7
11_5,45 12_5 13_4,61 14_4,28 15_4
Breathing
Hel
ical
Pitc
h (H
P)
Thikness 0.5mm Thikness 1mm Thikness 2mm
Helical Pitch vs. Breathing
1
1.2
1.4
1.6
1.8
2
11_5,45 12_5 13_4,61 14_4,28 15_4
Breathing
Hel
ical
Pitc
h (H
P)
Thikness 0.5mm Thikness 1mm Thikness 2mm
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 4
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PROCESS FOR BREATHING ACQUISITION AND MONITORING
Shift Point of Monitoring vs. Breathing
3.5
4.5
5.5
6.5
7.5
8.5
9.5
10.5
11.5
12.5
13.5
14.5
15.5
11_5,45 12_5 13_4,61 14_4,28 15_4Breathing
Mo
nit
ori
ng
Shift
(m
m)
Thickness 0,5mm Thickness 1,0mm Thickness 2,0mm
Ramp-up vs. Helical Pitch
0
5
10
15
20
25
1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9
HP
Ram
p-u
p (
mm
)
Thickness 0.5mm Thickness 1mm Thickness 2mm
Common Helical Pitch(Tracking Area)
Patient BreathingAcquisition by VisionRT
Detect the optimalHelical Pitch by Toshiba
Define the Monitoring & Respiratory
Point using VisionRT
Send the signalto Toshiba
Run thescan acquisition
Follow the movementof the Monitoring point
during the scanby VisionRT
Monitoring
Respiratory
Critical Issues• 0.5 mm thickness -> Impossible to acquire long volume• 1 mm thickness -> Step into the typical area of the breathing
acquisition• 2 mm thickness -> deformation artifact of the small structures
durin the reconstruction• HP with 1 decimal ->Bad calculation of the monitoring shift by
VisionRT
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 5
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RESPIRATORY SIGNAL REPEATABLE (PHANTOM TESTS)
Respiratory signal seems to be perfect and repeatable
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 6
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TOSHIBA HELICAL PITCH BIAS .... VISIONRT MONITORING BIAS (PATIENTS)
Exams Setup Parameters: one decimals Internal Machine Parameters: two decimals
Shift Point of Monitoring vs. Breathing
3.5
4.5
5.5
6.5
7.5
8.5
9.5
10.5
11.5
12.5
13.5
14.5
15.5
11_5,45 12_5 13_4,61 14_4,28 15_4
Breathing
Mo
nit
ori
ng
Sh
ift
(mm
)
Thickness 0,5mm Thickness 1,0mm Thickness 2,0mmMonitoring Point CalculationVisionRT Couch Velocity= Thickness*HP/Rot Time
One decimal or two decimal could have a big effect on the monitoring point determination
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 7
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VISIONRT VS. TOSHIBA BREATHING SIGNAL RAW DATA
Breathing Raw Data(VisionRT vs. Toshiba)
0
10
20
30
40
50
60
70
80
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Bpm
Vision RT Toshiba Inferior Threshold (2500ms) Superior Threshold (6500ms)
Breathing Raw Data(VisionRT vs. Toshiba)
0
5
10
15
20
25
30
35
40
45
50
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Bpm
Vision RT Toshiba Inferior Threshold (2500ms) Superior Threshold (6500ms)
Cough: rejected by the reconstruction
Mean respiration time
Which is the impact of the respiration time on the image reconstructions?
...I don’t know at the moment....
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 8
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TOSHIBA EDIT DATA TOOLS ... THRESHOLD EFFECTS
Raw data Post Process data
Resample with different breathing Threshold
Spike adjustmentsPerfect Breathing (post-processing)Resample of the breathing
3 different results – Same Images?????? (I do not believe...)
Game: Try to find the differences
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 9
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FREE BREATHING VS. THERMOPLASTIC MASK (PATIENTS)
Period Peak(Free Breathing vs. Termoplastic Mask)
0
4700
4775
4643
4442
4097 43
04
4472
4111
0
4275
4439
4480
4531
4459
4538 4754
5468
0500
10001500200025003000350040004500500055006000
2 3 4 5 6 7 8 9
Tim
e (m
s)
Free Breathing Termoplastic Mask
Phases Peak(Free Breathing vs. Termoplastic Mask)
6.21
29
6.19
51
6.15
69
6.17
74
6.27
79
6.20
03
6.14
1 6.19
23
6.15
66
6.27
06
6.16
72 6.21
23
6.20
06
6.26
94
6.27
29
6.21
37
6.15
2
6.24
33
6
6.1
6.2
6.3
6.4
6.5
4334 8609 13048 17528 22059 26518 31056 35810 41278
Tim
e (m
s)
Free Breathing Termoplastic Mask
Immagini CT con e senza mascheraVideo immagine assiale lesione
Free Breathing vs. Termoplastic Mask
0
1
2
3
4
5
6
7
0 10000 20000 30000 40000 50000 60000 70000 80000
Time (ms)
Phase
Free Breathing Termoplastic Mask
Very similar but the thermoplastic mask seams to help the patients to breathing correctly
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 10
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PHASE AND PERIOD DIFFERENCES
Free Breathing vs. Termoplastic Mask
0
1
2
3
4
5
6
7
0 10000 20000 30000 40000 50000 60000 70000 80000
Time (ms)
Phase
Free Breathing Termoplastic Mask
% Difference(Free Breathing vs. Termoplastic Mask)
-0.9%
0.5%
-0.9% -0
.4%
-1.2%
-1.2%
-1.4%
0.7%
0.1%
0.0%
9.0%
7.0% 3.5%
-8.8%
-5.4%
-33.0%
-6.3%
-2.0%
-5%
5%
Tim
e (m
s)
-40%
-35%
-30%
-25%
-20%
-15%
-10%
-5%
0%
5%
10%
15%
Phase Period
With thermoplastic mask:1. The amplitude phases seams
very similar during a long period of time
2. The period seams to be a limitation dependent by the patients
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 11
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Coordinate Variation ... Which phases?
CORDINATA Z (Th. 2,0mm)
-60.00
-40.00
-20.00
0.00
20.00
40.000
10
20
30
40
50
60
70
80
90
Spigolo 1 Spigolo 2 Spigolo 3 Spigolo 4Spigolo 5 Spigolo 6 Spigolo 7 Spigolo 8
CORDINATA Z (Th. 0,5mm)
-60.00
-40.00
-20.00
0.00
20.00
40.000
10
20
30
40
50
60
70
80
90
Spigolo 1 Spigolo 2 Spigolo 3 Spigolo 4Spigolo 5 Spigolo 6 Spigolo 7 Spigolo 8
CORDINATA X (Th. 2,0mm)
20.00
40.00
60.00
80.00
100.00
120.00
140.000
10
20
30
40
50
60
70
80
90
Spigolo 1 Spigolo 2 Spigolo 3 Spigolo 4Spigolo 5 Spigolo 6 Spigolo 7 Spigolo 8
CORDINATA Y (Th. 2,0mm)
-30.00
-20.00
-10.00
0.00
10.00
20.00
30.000
10
20
30
40
50
60
70
80
90
Spigolo 1 Spigolo 2 Spigolo 3 Spigolo 4Spigolo 5 Spigolo 6 Spigolo 7 Spigolo 8
CORDINATA X (Th. 0,5mm)
20.00
40.00
60.00
80.00
100.00
120.00
140.000.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
Spigolo 1 Spigolo 2 Spigolo 3 Spigolo 4Spigolo 5 Spigolo 6 Spigolo 7 Spigolo 8
CORDINATA Y (Th. 0,5mm)
-30.00
-10.00
10.00
30.000
10
20
30
40
50
60
70
80
90
Spigolo 1 Spigolo 2 Spigolo 3 Spigolo 4Spigolo 5 Spigolo 6 Spigolo 7 Spigolo 8
The best reconstruction....
Phases 20% - 60% seams the most
repeatable
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 12
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Phases vs. HU Variation
HU Variation - Thikness 1mm(Superion Lobe Lung Sx)
-40
-20
0
20
40
60
80
100
0 10 20 30 40 50 60 70 80 90
Phases
HU
Termoplastic Mask
HU Variation - Thikness 3mm(Inferior Lobe Lung Dx)
-50
-40
-30
-20
-10
0
10
20
30
40
0 10 20 30 40 50 60 70 80 90
Phases
HU
Free Breathing
HU Variation - Thikness 3mm(Inferior Lobe Lung Dx)
0
5
10
15
20
25
30
35
40
0 10 20 30 40 50 60 70 80 90
Phases
HU
Free Breathing Termoplastic Mask
HU Variation - Thikness 3mm(Medial Lung Sx Nodule)
-900
-800
-700
-600
-500
-400
-300
-200
-100
00 10 20 30 40 50 60 70 80 90
Phases
HU
Free Breathing Termoplastic Mask
Phantom HU Variation
0
50
100
150
200
250
300
350
400
450
500
0 10 20 30 40 50 60 70 80 90
Phases
HU
Thikness 3mm Thikness 1mm
• Thickness variation means HU variation• Phases variation means HU variation • Position of the lesion means HU variation
• Which dose calculation do I have to do?• Which HU do I have to consider?
• May be a average MIP could be a good compromise
• ....do not believe absolutely to your calculation
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 13
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PATIENTS AT MODENA ....(4 PATIENTS DONE!! BUT MANY QUESTIONS TO SHARE....)
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 14
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4D DOSE RECONSTRUCTION OF THE RESPIRATORY PHASES(Possible!!! But I will be crazy, if it will be a clinical routine (3 days of work)) ... Some open issue about the deformation
4D TOMOTHERAPY DOSE RECONSTRUCTION
Dose Matrix (Phase 20%) +Dose Matrix (Phase 30%) +Dose Matrix (Phase 40%) +Dose Matrix (Phase 50%) +Dose Matrix (Phase 60%) +------------------------------------4D Dose Reconstruction
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 15
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Proton-Therapy.....
Few questions in my mind.....may be I need to change my mind!!!...are we sure about the dose calculation?...we will try to investigate the problems with the mesothelioma group (BRMOTRFI)
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 16
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... Someone better than us...
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 17
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Conclusion.....
1. Enthusiastic time and results about 4D exams2. Toshiba and VisionRT easy way to work with it3. Pulmonary and abdominal tracking can create different results4. Tracking signal must be investigated before to consider a perfect surrogate of the
target and OARs movements and the reconstruction usable for clinical dose calculation
5. Long time for post process and contouring can distort the patient objectives6. Many open issues about the ramp, thickness, HU, reconstructions, etc...
Which protocols?Purpose by Modena.... (Work in Progress)1. 1° Scan : 2mm Thickness (Scan set include minimum the total lungs)2. 2° Scan : 0.5mm Thickness (Scan set to include only the details or tumors)3. Reconstruction of the multiple phases (0% - 90%)4. Threshold respiration between 2500ms and 6500ms (9-25 BPM)5. Use of the 20% -60% phases to evaluate the average CT Dataset for dose
calculation purpose6. Evaluate and contouring the target volume on the best CT Data Set (0.5mm)7. Contouring all the phases and define an envelope target of the multiple phase
(ITV)8. DO NOT REDUCE THE MARGIN EXPANSION LESS THAN DOSE VOXEL DIMENSION
2-3mm9. .......MANY OTHER ISSUES MUST BE INVESTIGATED!!!!!
Can change the results of our treatment the 4D? The word must be passed to the doctors... But if someone want to work with us, it will be
a pleasure!!
2.10.2009 La TC - 4D con sistemi di tracking ottico di superficie - G.Guidi, L.Binotti, et.al. 18
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Acknowledges
“… under the “Ghirlandina” Tower….…..new opportunities and ideas are growing …
…and many people are working on it”
4D
Physicist Doctors
Medical Physics Dpt.Director: T.CostiPhysicist:• E.Cenacchi• B.Franzoni• A.E.Francia• G.Gottardi• G.GuidiDosimetrist• L.Boni• L.MoriniStudent• L.Binotti• P.Ceroni
Doctor:• M.Amadori• P.Antognoni• G.De Marco• P.Giacobazzi• M.Parmiggiani• S.Pratissoli• S.Scicolone• G.Tolento• All thereapist
U.O. Radiation Oncology
Director: F.Bertoni
Special Thanks to Luca, Elisa & Luciano
Will I see a 4D Tomotherapy Treatment?