7/30/2011
Summarize some basic strategies that you
already know
Jerry Soen
Talk through these strategies and how
they were applied in two real life projects
MS, Senior Medical Physicist, Advocate Christ Medical Ctr.,
Oak Lawn, Il.

Mark Pankuch

Director and Medical Physics and Dosimetry – CDH
CDH--Proton
Center, Warrenville, Il.
Acceptance and commissioning TPS
Implementation of 44-D CT into the proton
environment
The field of Radiation Oncology is rapidly advancing

New technologies
Advances
Ad
/ upgrade
d tto currentt equipment
i
t

Think back to your training and the basic skills you
acquired and strengthened in school.
Mentally
M t ll switch
it h gears from
f
the
th fast
f t pace off the
th clinic
li i
to the thoughtful processes of research
New process and uses for new and current equipment

Much of the burden for planning and implementation falls
on the Medical Physics Staff
If you hire a consulting physicist, you still need to
know the process, the results and the limitations of
the system.
What does this new system
accomplish?
“ When an we start using ____”
Ability to perform new treatment techniques

Rapid Arc, VMAT, IGRT
I
Improved
d on older
ld ttechniques
h i

Frameless SRS
What are the expectations for use in your
clinic

4-D CT
Prospective, Retrospective, Gating
1
7/30/2011
Take the time to study the
Background
How was it created?
Understand the basic physics involved
Background and White Papers produced by
manufacturer
Who created it?

Vendor, Universityy Group
p
Journal articles referenced by manufacturer
Why was it necessary?

Where we not so good in the past (IGRT)
How will this help my clinic?

What do your Doctors, Administration,
Therapists expect
Get to know your colleges that have
approached the paradigm before
Read manual, actively participate in training
Learn what you new system can and cannot
do. Understand limitations.
Gather data obtained by others
Don’t reinvent the wheel
Through journal articles they’ve written
Through the Manufacturer
University Physicists that have already
developed it
Look at other’s work and
appreciate trends in data
Identify outliers of data
and explain them
AAPM Chapter physicists
Obtain the appropriate equipment
Special phantoms or chambers to gather
information
QA equipment necessary for ongoing
quality assurance of the particular
paradigm.
Include all that you need in the
purchase of the new paradigm.
DON’T CHEAT YOURSELF.
Play the safety card if necessary.
Show your administrator swollen, twisted
pain ridden bodies if necessary – GET
WHAT YOU NEED.
2
7/30/2011
Outline a plan of attack
Work from a simple model that is intuitive but
can be easily verified to a high degree of
accuracy..
accuracy
Make you model more complex and test
Stress the paradigm – Find out what are its
limitations, NOTHING IS PERFECT, There is
no such thing as 100% right. Understand the
error bars.
Plan for enough time
Do not work alone
Attend meetings
Use vendor contacts
Local AAPM Chapters
Initiate outside contacts
Go home and sleep at night.
Equipment fails
Unexpected results
Remain flexible
There will never be enough time
Lets discuss this theory in
practical clinical examples
Commissioning of the CMS Monaco
Treatment planning System
Accelerator and Treatment
planning Commissioning
Implementation of 44-D CT into the proton
therapy environment
Jerry Soen, MS, DABR, FACR
Senior Medical Physicist
Advocate Christ Hospital, Oak Lawn, Il.
3
7/30/2011
What were the Goals to be
accomplished
Our goal here
Not to explain the whole process but to
3. Help you to not see these caveats as brick
walls but opportunities to learn and to either
bust through, leap, or walk around them

Breakdown of tasks
Data acquisition phase
1. Photon data for each accelerator – both
algorithms
•
2. Electron data for each accelerator –
Pencil beam
Acceptance of New Elekta Accelerator
Data input to Xio TPS and commissioning
both
photon and electron algorithms
Send data to CMS for Monaco
commissioning
Calibrate new accelerator
Verify accuracy of Xio data for TPS
•
•
•
•
Things I needed to know
•
•
•
•
•
•
•
•
•
•
Acceptance
p
and Commissioning
g of new Elekta Infinity
y
accelerator
•
Commissioning of CMS Xio for Convolution /
Superposition algorithms
•
Verification with CMS of complete and proper
acquisition of Monte Carlo data for CMS / Monaco
2. Talk about caveats that may appear along
the way

•
•
Data acquisition for Varian 2121-ex and Elekta Infinity
accelerators for both CMS Xio and Monaco TPS
1. Help you think through the whole process

•
•
What will be the end results of my work
New techniques
New ways of doing established techniques
New algorithms
What helps me get there from here
Equipment that I need
Software products that I need to use
What is my time frame for accomplishment
What is the quality that I need to achieve
Some Caveats going in
All scanning had to be performed with the
facilities’ PTW scanner
All scan and nonnon-scan data had to
conform to CMS guidelines for each
algorithm
All Monaco scan data had to be sent to
CMS for verification prior to acceptance
for commissioning by CMS
What will be the end results
of the Work
• VMAT utilizing MONACO (Monte
Carlo) Algorithm
• Moving from Clarkson to Conv/Super
Conv/Super
for 3D planning
• Fit of Conv/Super
Conv/Super for CMS Xio IMRT
planning for Varian
Varian--21ex and Elekta
Infinity
• New Accelerator – Elekta Infinity
4
7/30/2011
What should I know
How can I know
• Do some research
• As much as possible about the history
and the background of these algorithms
and accelerators
• Understand the strengths and
weaknesses of the algorithms
• How do these algorithms deal with
heterogeneities, curved surfaces,
various densities, target volume sizes,
etc.
•
•
•
•
•
Websites – Elekta.com, Varian.com
Technical Reports and ‘White Papers”
from the company – they explain the
history and
reasoning behind their
choice of algorithm
Talk to physicists that are very familiar
with the
productproduct- NEVER ACT ALONE
Research papers that discuss the
implementation of
these products
Web--ex training sessions
Web
Why do I need to know
What else do I need to
know
• YOU ARE THE PHYSICIST!
• You have to be able to troubleshoot
problems
• Good quality assurance necessitates
and
understanding of all
components
• The weaknesses of the systems will
eventually show themselves, you need
to be able to explain them
• The data I need to take for each algorithm and the
format of the data
• How the data is to be taken on the phantom
• How
H
it may h
have tto b
be reformatted
f
tt d for
f exportt to
t
either the TPS or the TPS company
• Read, study, memorize and other wise thoroughly
digest TGTG-106
• Accelerator beam data commissioning equipment
and procedures, Indra J Das, et al, Med Phys
35(9), 9/2008
Beam Data Collection
Sheets
Beam Data Collection
Sheets
•They tell you:
•
•
•
•
•
What data to collect
The extent of data to be collected
Format
Chamber sizes to use
Non-scan data
5
7/30/2011
What else do I need to
know
•
•
•
•
•
Your scanning phantom and your dosimetry
equipment
You should be well schooled in the phantom you
will use – Take time to practice how to take data
Know what you can change and how to setup the
phantom
Know the manual – Most manuals are hard to
understand often because they are translated
Establish a preflight check of your equipment
Know what is ‘good’ data and ‘bad’ data
Non--scan Data
Non
Think while you scan
• Put all nonnon-scan data into spreadsheets
• Plot and fit nonnon-scan data where
possible while taking it
• Output factors – Sp,
Sp Sc
Sc, OF
OF, etc.
etc
• Use spreadsheets to accurately
calculate output and wedge factors
and virtual source distances,
etc.
• Take this data when you are fresh
• Compare it against other published
data for comparison
•
•
•
•
Recheck your setup constantly
Does this data make sense?
Follow a checklist
After each set of scans review what you
have to make sure you have it all
• Make electronic copies of all that you
do and put them somewhere else
• Don’t keep your scanning chamber in
water longer than 8 hours
Real time analysis avoids
mistakes
Real time analysis avoids mistakes
23IX 6X Photons Output Factors
Measured @ dmax
OF
6X OF measured @ dMax
Field
Field
Size
nC
Size
OF
2
3.29
2 0.873
3
3.41
3 0.905
4
3.48
4 0.923
5
3.55
5 0.942
6
3.61
6 0.958
7
3.65
7 0.968
8
3.69
8 0.979
10
3.77
10 1.000
12
3.38
12 0.897
15
3.89
15 1.032
20
3.97
20 1.053
25
4.03
25 1.069
30
4.09
30 1.085
35
4.13
35 1.095
40
4.16
40 1.103
1.200
1.200
1.000
1.000
0.800
0.800
0.600
OF
Output Factors
•
‘Good’ Data vs ‘Bad’
Data
Series1
Poly. (Series1)
0.600
y = -0.00000042x4 + 0.00004303x3 - 0.00162797x2 + 0.03009878x + 0.82423954
0.400
0.400
0.200
0.200
0.000
-5
0.000
0
10
20
30
40
0
5
10
15
20
25
Field Size (sq cm)
30
35
40
45
50
6
7/30/2011
Once scanning is
complete
•
Data sent back to TPS
company
Prepare it for either return to the company or consultant or
local beam fitting
Local beam fitting can be difficult.
•
Some p
portions are intuitive
•
Others are nonnon-intuitive and do not seem to make sense –
Don’t be afraid “If man can make it and break it, you can fix
it”
•
Don’t stall out – start asking questions
•
Utilize tools that are given to you, try different things to see
the effects, learn the limits
•
Keep pressing buttons
•
• Two sets of data were reviewed by two
different physicists
•
1. One showed comparative data from other
facilities and requested a retake of some
data
2. The other did not understand the process
well and as a result there were major
portions that had to be reacquired in formats
different from what was specified
•
Local Commissioning
Local Commissioning
• Remember
• Utilize helps given to you by the
company
•
•
Elekta-CMS provides commissioning
Elektaguides on their website
website.. It provides
•
•
•
•
Accelerator specific information
Steps of action
Documentation Warnings (Do not avoid these)
Help desk
•
•
•
•
Varian provides
•
•
•Photons – Preconfigured beam data, technical guides
•Electron (PB) & (MC) have technical guides and
‘cookbooks’
•Excellent help desk
•
Verification
•
•
•
•
•
•
Start from the intuitive and simple
Have the right equipment – today’s new
paradigms require the latest quality assurance
equipment
q p
Administrators are now attuned to safety
concerns
Learn to trust your equipment
Establish a plan of verification before you start
Do not try to be exhaustive – TPS are no longer
table lookup they are calculation engines
Not everything will fit perfectly – there are
reasonable limits
Tighten your fits where most of your
plans will be used – 4x4 to
treatment p
20x20
IMRT planning – 1x1 to 10x10
Wedges – 5x5 to 15x15
Find someone who can review what you
are doing
Your verification will find any errors that
need to be corrected
Verification





Read, memorize and otherwise digest the
following Task Groups and
subcommittees – 53,114, 142, and IMRT
Subcommittee
Quality Assurance for clinical radiotherapy treatment planning –TG 53, B.
Frass,, et.al, Med Phys 25, 10/1998
Frass
Verification of monitor unit calculations for nonnon-IMRT clinical radiotherapy
–Report of AAPM Task Group 114, Robin Stern, et.al. Med Phys 38,
01/2011
Quality assurance of medical accelerators – TG 142, E. Klein, et.al. Med
Phys, 10/2009
Guidance document on delivery, treatment planning, and clinical
implementation of IMRT: Report of the IMRT subcommittee, G. Ezzell
Ezzell,,
et.al, Med Phys, 30, 08/2003
7
7/30/2011
This is not intuitive
Simple Verification tools
Eclipse Monitor Units to
deliver 100 cGy
Field Size
Depth
1.5
5
10
5
105
115
143
10
99
107
128
15
96
103
120
20
94
100
116
15
178
155
144
136
20
224
193
174
163
5
10
15
20
Monitor Unit difference Eclipse vs RadCalc
5
10
15
20
5
10
15
20
1.5
-2
-1
-1
-2
5
-2
-1
-1
-1
10
0
1
0
1
Enhanced Dynamic Wedge Check
23IX
Depth of 5 cm
10x10
6 MV
@dmax
wedge
Mu to
Del.
100cgy
Open 10 x 10
Degree Reading
1.75
10
1.53
114
1.75
15
1.49
117
1.75
20
1.45
121
1.75
25
1.41
124
30
1.36
129
45
1 23
1.23
142
60
1.04
168
20x20
wedge
Degree Reading
10
1.5
15
1.4
20
1.32
25
1.24
30
1.16
45
0.94
60
0.71
Mu to
Del.
100cgy
117
125
133
141
151
186
246
Oct-08
Eclipse
AAA-MU
113
116
119
122
126
139
163
Average error
-1.21
-1.23
-1.40
-1.70
-2.08
-2.30
2 30
-3.13
-1.87
Eclipse
AAA-MU
115
122
130
138
147
181
240
Average Error
-1.43
-2.40
-1.94
-2.22
-2.56
-2.78
-2.63
-2.28
IMRT or Complex Paradigm
Verification
20
4
5
2
2
Potential % Differences in Dose Delievered
RadCalc vs Measured
1.5
5
10
15
20
0.94
0.86
0.00
-0.56 -1.79
0.00
0.93
-0.78 -1.28 -1.57
0.00
0.97
0.00
0.00
-0.58
1.05
0.00
-0.86
0.00
-1.23
Oveall average
error
-0.1943
Simple Verification tools
15
1
1
1
1
5
10
15
20
5
10
15
20
5
10
15
20
RadCalc Calculated Monitor
Units
Normalized to 10 cm
1.5
5
10
15
107
117
143
177
100
108
127
154
97
104
120
143
96
101
115
135
20
220
188
172
161
Measured vs. Eclipse calculated MU
Open Fields
1.5
5
10
15
20
3.57
3.25
2.64
2.12
1.69
3.78
3.52
2.96
2.43
1.98
3.91
3.66
3.15
2.64
2.18
3.99
3.76
3.27
2.79
2.32
1.5
5
10
15
20
106
116
143
178
224
100
107
128
156
191
97
103
120
143
173
95
101
116
135
163
1.5
5
10
15
20
0.95
0.87
0.00
0.00
0.00
1.01
0.00
0.00
0.65
-1.04
1.04
0.00
0.00
-0.69 -0.57
1.06
1.00
0.00
-0.74
0.00
OAE
0.18
-0.03
Simple Verification tools
6 MV % Diff. Measured vs CMS Calculated
Upper 15deg 30deg 45deg 60deg 23IX
5*5
0.50
1.14
0.69
0.85
10*10
0.56
0.43
0.39
0.00
15*15
0.60
0.93
0.00
0.34
20*20
0.63
0.98
0.43
30*30
0.00 -1.61
OAE
0.40
20 MV % Diff. Measured vs CMS
Calculated
Upper 15deg 30deg 45deg 60deg
5*5
-1.97
0.00 -0.86 -0.35
10*10
0.00
0.00
0.00
0.00
15*15
0.74
0.61
0.00
0.00
20*20
0.00
0.00 -0.51
30*30
-0.80 -0.67
OAE
-0.22
IMRT or Complex Paradigm Verification
•Start with a simple plan
•Utilize your simple Solid Water QA phantom as
your patient
•Move to an anthropomorphic phantom if
available
•Transfer plans to electronic quality assurance
devices and perform quality assurance
•These quality assurance measurements should
have very good results
•If simple plans do not have good verification
results, begin to check the items which
can most influence the plan first
•Dosimetric leaf gap
•Radiation output specification
•MLC transmission
•If all else fails, begin to ask questions
•Step back for a period of time
•Remember it is intended to work correctly
•If they do, move to more complicated plans
8
7/30/2011
In Conclusion
•Take time to discover what you need to know
•Try to have someone work with you
•Utilize spreadsheets and graphs to help you look at
data
published data to compare
p
•Utilize other p
•Have someone who has done this before help to
review your data
•Do not try and force error bars to something
unachievable
•Document, Document, Document
Implementation of 4
4--D CT into
the proton therapy environment
Why 44-D CT for Protons?
In Proton Therapy, there is a sharp fall off
at the distal edge of the treatment field
g is moving,
g, the equivalent
q
If the target
path--length of the protons can vary
path
Incorrect calculations of the path
path--length
can lead to extreme under dosing of
targets or extreme overdosing of critical
structures.
What are we trying to achieve
with 4
4--D CT?
Target have the potential to move as a
result of the respiratory cycle
Current imaging methods were obtained
on static target or a blurred moving target
Blurring of a moving target would not yield
correct depth measurements
Gather Information
Task Group 76 : The management of respiratory motion
in radiation oncology Med. Phys. 33 (10), 2006.
Knopf et al. Workshop on 4D4D-treatment planning in
actively scanned therapy
therapy. Med
Med. Phys
Phys. 37 (9)
(9), 2010
2010. Europe
Y Kang et al. 4D Proton Tretment Planning Strategy For
Mobile Lung Tumors. Int. J Rad Onc Biol Phys 67 (3)
2007 - MD Anderson
9
7/30/2011
Talk to those with experience
“Active 44-D Lung Treatment Gating and
Tumor Tracking” Anil Sethi
Sethi,, Iris Rusu –
Loyola University
University, Chicago
Chicago, IL
Thoracic Workshop Program
ProCure Proton Therapy Center, Oklahmoma City; August 20 - 21, 2010
Date: August 20 – Friday
16:00 ‐ 17:00 pm:
17:00 – 17:15 pm:
17:15 – 17:45 pm:
17:45 – 18:30 pm:
18:30 – 19:15 pm:
19:15 – 19:45 am:
19:45 – 20:45 pm:
20:45 – 21:00 pm:
21:00 – 21:15 pm:
21:15 pm
ProCure Thoracic Workshop, OKC, Ok.
What are the limitations of the systems?
Reconstruction Pattern



Prospective
Retrospective
Breath Hold,
Hold Gating
What limits capability?


CT scanner
Treatment delivery system
Active scattered vs. passive
Understand the process
Vendor Training
Arrival + Tour of ProCure Center + ICIO
Sameer Keole + Niek Schreuder
The OKC facility
The OKC patient population and the need to treat lung tumors
Sameer Keole + Kiran Prabhu Avril
The MDA way of treating lung cancers – Case mix and protocols
Richard Amos + Joe Chang
Dinner Break
Larry Kestin
Lung treatments in a general perspective
What’s done in photon world and the role of protons in lung treatments
The technical challenges of treating lung tumors with protons
Using Passive scattering – 4D CT + Margins etc
Richard Amos
Using Uniform Scanning
Omar Zeidan + Anthony Mascia
Some clinical cases from the first Chicago CDH treatments Mark Pankuch
The initial results on Ridge filter based US for lung treatments
Niek Schreuder
Using respiration management
Jerry Jesseph
Short summary + Wrap‐up for the day
Niek + Sameer
Date: August 21 – Saturday morning
8:30 – 9:15 am:
The UFPTI way of treating lung cancers – Case mix and protocols
9:15 – 10:15 am:
What shall ProCure treat in OKC: general discussions
1. The Short term focus
2. The long term focus
10:15 – 10:30 am:
Break
10:30 – 11:30 am:
What lung protocols shall PCG open or Join
11:30 – 12:30 am:
Next steps and action items
Zuofeng Li + Brad Hoppe
Sameer + Niek + others
Larry Kestin + Sameer
Niek
Get the equipment you need
CT Phantoms


Acrylic Head Phantom
Home made 4
4--D Phantom
Number, Location and Space for 44-D Work
Stations
System to review proton doses in different
phases of the cycle \ Auto contouring tool
Address any Regulatory
Considerations
Additional Shielding needed in CT room
due to higher usage factors
Calibration Phantom / 44-D Home Phantom
Patient Dose measurements
D
Documentation
t ti off MSAD ffor St
State
t
regulations
Experiment with techniques/parameters to
better understand the system
Evaluation of larger CT dose from
Radiation Safety / ALARA
10
7/30/2011
Work--out Work
Work
Work--Flow
Organize the implementation
4-D would be used for Lung patients
Contour using MIP and Mean
Due to clinical limitations at the start, lung
treatment would be considered lower priority
Develop a method to produce dose
calculations on all ten phases Contouring
Tools
Goal was to Begin Simple
First cases were not Lung
Colleges from ProCure Thoratic
symposium
i
h d shared
had
h d th
their
i concerns with
ith
prone treatments of spine target
Had unexpected needs for 44-D Imaging


Simple 4
4--D Opportunity
Prone Spine
Prone CSI
Adapt as you learn more
4-D Scan would give us information on the
magnitude of movement of spine
MIP vs Ave
Test movie loops to verify dose
Have a physicist and dosimetrist present
att the
th time
ti
off simulation
i l ti
Imaging dose would be higher than without 44 -D

Physicians agreed risk worth the benefit
After contouring on MIP, preferred to
review contours on movie loop before
planning
Excellent Candidates
11
7/30/2011
Work--Flow Modifications
Work
Where are we now?
All Prone spine fields use 44 -D
Lung cases have begun

Limited to <1.0cm of motion
Abdominal cases being reviewed
Dose optimization and adaptive planning
In Conclusion
In Conclusion
Your Centers will ask you to implement
new technology.
Reiterated what your advisors taught you
on proper scientific technique
It will be your responsibility to ensure it is
done correctly and is determined safe for
the patients
Medical Physics is a community with a
unified goal to provide better, safer care.
Embody the “team” approach, even if you
are alone.
12