EARL FDG-PET/CT Accreditation Programme: Feasibility, Overview and
Transcript of EARL FDG-PET/CT Accreditation Programme: Feasibility, Overview and
EARL FDG-PET/CT Accreditation Programme: Feasibility, Overview and Results of First 45 55 Successfully
Accredited Sites
_
Overview of presentation
•
Why
do you
need
accreditation?
‐
background on
SUV uncertainties
•
What
has been realized
so
far
by
EARL?
•
How
to get
accreditation?
•
Results
for
the first
55 sites
Standardised Uptake Value
][/][]/[
kgweightMBqDosemlkBqcSUV t
TBW
SUV ‘is’
activity concentration ratio
Weight is sometimes replaced by BSA, LBM, BMI…
Use of SUV in response assessment studies
Absolute SUV:-Patient
eligibility
-Patient
stratification-Lesion
selection
(PERCIST)
-Residual
SUV
Relative
of % SUV changes-% change
of the same
lesions
(EORTC)
-% change
of the (5) hottest lesions
per scan + ΔSUV=0.9 (PERCIST)
For all applications
absolute SUV and SUV changes
are used
PET imaging / SUV uncertaintiesTechnical factors–
Relative calibration between PET scanner and dose calibrator (10%)–
Residual activity in syringe (5%)–
Incorrect synchronisation
of clocks (10%)–
Injection vs
calibration time (10%)–
Quality of administration (50%)
Physics related factors–
Scan acquisition parameters (15%)–
Image reconstruction parameters (30%)–
Use of contrast agents (15%)–
ROI (50%)
Biological factors–
Uptake period (15%)–
Patient motion and breathing (30%)–
Blood glucose levels (15%)
R. Boellaard
2009, J Nucl
Med Supplement Issue 50: 11S
Impact of blood
glucose level
Glu
200 mg% Glu
79 mg%Karoline Spaepen-Sigrid Stroobants
Department of Nuclear MedicineUniversity Hospital Gasthuisberg
Leuven, Belgium
Factors affecting SUV biological factors –
uptake period
Lowe VJ et al. Optimum scanning protocol?for
FDG-PET evaluation of pulmonary malignancy. J Nucl
Med. 1995, image taken from Shankar et al. JNM 2006
Outcome of quantitative FDG-PET studies using standardised
uptake values depend on many biological and technical (physics) factors
*Example of one of the many small
factors: effects of different number of OSEM iterations, as seen in the Netherlands, on SUV
SUVmax
= 4.0
5.9
6.4
8.6SUV 50%= 3.0
4.1
4.6
5.9
Types of standards
/ recommendations
•
Minimal performance standards:–
“Focus”
on
accuracy
–
Lower
threshold
•
Harmonizing
performance standards–
“Focus”
on
reducing
inter‐institute, ‐scanner, ‐
patient
variability
–’precision’–
Lower
and
upper limits
Scanner validation
program
Need
for
harmonisation
of resolution-dependent quantitation, rather
than
minimal performance standards0 1 2 3
Hospital
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Site
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rage
SU
V
FDG PET standardisation
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Site
Ave
rage
SU
V
W/o standardisation
and
with standardisation
(today)
Primary
aim
of EARL harmonising
QC
program: Reducing
inter
and intra institute
variability
in SUV results
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2
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V
FDG PET standardisationWith standardisation
today and……………………….tomorrow
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2
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Site
Ave
rage
SU
VPrimary
aim
of EARL QC program (NOW): Reducing
inter
and intra institute
variability
in SUV results
Secondary
aim
(NEXT)Enhance
a common
harmonized
standard
Overview of presentation
•
Why
do you
need
accreditation?
‐
background on
SUV uncertainties
•
What
has been realized
so
far
by
EARL?
•
How
to get
accreditation?
•
Results
for
the first
55 sites
FDG PET and PET/CT: EANM Procedure Guidelines for Tumour
PET Imaging:
version 1.0
Eur.J.Nucl.Med.Mol.Imag. 2010
The EANM guideline for FDG PET and PET/CT
provides recommendations for:
•
Minimising
physiological or biological effects
by patient preparation guidelines
•
Procedures to ensure accurate FDG administration
•
Matching of PET study statistics (‘image quality’)
by prescribing FDG dosage as
function of patient weight, type of scanner, acquisition mode and scan duration
•
Matching of image resolution
by specifying image reconstruction settings and
providing activity concentration recovery coefficients specifications (QC
experiment)
•
Standardisation
of data analysis
by prescribing region of interest strategies and
SUV measures
•
Multi‐center QC/QA
procedures for PET and PET/CT scanners
Multi‐center QC and calibration
•
Daily QC conform standard procedure of system /
manufacturer
•
Calibration QC using (cylindrical) phantom (15‐30cm
diameter)
• “Adjusted”
NEMA NU 2‐2001 Image Quality
procedure/measurement to measure recovery coefficients
as function of sphere size (= ‘effective image resolution’)
•
CT‐QC cf
recommendations of ESR/national law
•
Misc. QC (e.g. for scales, alignment etc)
Based on the QC experiments as described in the EANM guideline
published in EJNMMI 2010
Manuals, SOPs, online questionnaire completed in August 2010
Training of EARL coordinator (S. Ettinger) September 2010,phyiscs
and scientific
support provided
by
T.Sera
& R.Boellaard
Pilot program (in collaboration with EORTC, trail EORTC 22071‐
24071) began in October 2010
European accreditation program EARL, EANM, EORTC
Accreditation: current
status..
•
Web portal for
uploading
QC data established
•
SW tools for
semi‐automated
analysis
of results
•
Semi‐automated
storage
of results
in dbase
•
First pilot
(n=12) succesfully
completed
in March
2011
•
At present more than
50 sites accredited
•
Accredited
sites will
be
listed
on
EARL site
•
Signet:
•
Program formally
endorsed
by
EORTC
Overview of presentation
•
Why
do you
need
accreditation?
‐
background on
SUV uncertainties
•
What
has been realized
so
far
by
EARL?
•
How
to get
accreditation?
•
Results
for
the first
55 sites
Accreditation: website & submission
portal
How to get accredited (1) ?
• Express interest through
EARL website
• Sign
written
agreement
to comply
with
guideline
(GL)
• Fill
out online questionnaireinformation
on
PET/CT systems, DC, wellcounters, SW etc
• Perform
QC experiments
as described
in GL• Manual• SOP for
calibration
QC
• SOP for
image quality/SUV recovery
QC
How to get accredited (3) ?
• Calibration
QC specification:•
maximum allowable
calibration
deviation
= + or
–
10%
(global)
• SUV recovery
specifications:• for
SUVmax
(focus –as SUVmax
is used
clinically!)
• for
SUVmean
0.0
5000.0
10000.0
15000.0
20000.0
[BQ
ML]
VOI A50%, new limits
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0.1 1 10 100
Sphere volume (mL)
SUV
reco
very
coe
ffici
ent
VOI A50%, new limits
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0.1 1 10 100
Sphere volume (mL)
SUV
reco
very
coe
ffici
ent
Standardised
software tools for analysis and interpretation of
QC experiments were developed:
European accreditation program EARL, EANM, EORTC
Calibration QC:-
Automatic VOI placement- Verification of calibration- Verification of inter-&intra-plane uniformity
IQ QC- Recovery coefficients (volume & act.conc.)- Cold spot recovery using central insert (scatter)- Verification of calibration using back ground VOI
Multicenter
FDG PET/CT quantification
0 1 2 3
Hospital
4.00000
8.00000
12.00000
16.00000
SUV
51-6
1 m
in n
orm
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wei
ght s
can
1
Need
for
harmonization
of resolution-dependent quantitation, rather
than
minimal performance standards
Overview of presentation
•
Why
do you
need
accreditation?
‐
background on
SUV uncertainties
•
What
has been realized
so
far
by
EARL?
•
How
to get
accreditation?
•
Results
for
the first
55 sites
Multi‐center
harmonization
of quantification
• Occasionally
it
takes
1-4 iterations
before
IQ-RC is within
specs•
RC harmonizing
specs
‘centered’
around
RC=1 for
SUVmax
for
spheres
larger
than
2.5 mL
0.0
5000.0
10000.0
15000.0
20000.0
[BQ
ML]
Results pooled over all experiments
0
0.25
0.5
0.75
1
1.25
1.5
1.75
2
0.1 1 10 100
Sphere volume (mL)
Rec
over
y co
effic
ient
GE=blue, Philips=red, Siemens=green
0
0.25
0.5
0.75
1
1.25
1.5
1.75
2
0.1 1 10 100Sphere volume (mL)
SUV
RC
Some
‘typical’
image artefacts
Edge
or
ring (Gibbs) artefacts:
•
Nearly
always
seen
with
PSF based
reconstructions
•
Frequently
on
specific
TF systems
(>50% of cases)
Some
‘typical’
image artefacts
75 kg patient, 120 MBq, 3 min/bed(BG = ~1kBq/cc)
0.25
0.5
0.75
1
1.25
1.5
0.1 1 10 100
Sphere volume (mL)
Rec
over
y co
effic
ient
VOI & EANM VOI & PSF+TOFMAX & EANM MAX & PSF+TOF
Ring artefacts
give
upward
bias in SUVmaxR. Boellaard, JNM 2011 +Many
pres @eanm2012
Use
of PSF-recon
requires
change
of data analysis
(i.e. SUVmean)-
VOI based-
No std
VOI method
yet
(CT, PET)
- SUVmax
is usually
used
clinically
Use
of SUVmax
–
EANM -STD
Why
do we use
SUVmax
SUVmax
suffers fromupward
bias due
to noise
(Boellaard
et al, JNM 1996, 2011, Lodge
et al, JNM 201poor
reproducibility
and accuracy
for
PSF (HD) reconstructions
(Boellaard
et al., JNM 2011, Tong, IEEE TNS 2011)
Despite
these limitions:• May represent
metabolically
most active
part of tumor
• VOIs
are not
standardized• CT and PET based
manual
segmentation
suffer
from
observer
variability• PET based
automated
delineation
methods:• variability
of methods• variability
in implementation
of same
method•
performance depend
strongly
on
underlying
image characteristics
(Cheebsumon
et al. JNM2011, EJNMMI 2011)• cannot
deal well
with
tracer
uptake
heterogeneity•Therefore, need
to optimize
image quality
for
use
of SUVmax
RC specifications for SUVmax
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0.1 1 10 100
Sphere volume (mL)
SUV
RC
Multi‐center
harmonization
of quantification
0.0
5000.0
10000.0
15000.0
20000.0
[BQ
ML]
-15
-10
-5
0
5
10
15
0 1 2 3 4
1=GE, 2=Philips, 3=Siemens
% c
alib
ratio
n er
ror i
n N
EMA
BG
Comparable
calibration
accuracy
and SUV recovery
among
sites and vendors is feasible
(n=55)
Multi‐center
harmonization
of quantification
Scanner performance harmonization
is feasible
on
a large
scale, but
long term sustainability
requires
support and service from
vendors –goal of SNM-CTN & EANM/EARL
VENDORS could:- Include
EARL accreditation
in acceptance
testing
OR
-
Setup
EARL compliant
protocol during
application
training- HD-TOF reconstruction
for
visual
inspection
+ 2nd online EARL recon- HD-TOF reconstruction
for
visual
inspection
+ EARL compliant
postprocessing- either
of these 2 are saved
as EARL STD protocol
Multi‐center
harmonization
of quantification
Main
principles
of EANM GL and EARL accreditation• Standardisation
of PET examinination
–procedure• Quantification
is combination
of:• image resolution• image noise• data analysis
methods
(SUVmax
de facto
the standard
in practice)
• EARL QC’s
s based
on
exploration
to find
highest
common
denominator
in • performance of scanner calibration• SUV-RCs
–
SUVmax
!!
•
Scanner performance harmonization
is feasible
on
a large
scale, but
long term sustainability
requires
support and service from
vendors –goal of SNM-CTN & EANM/EARL
Why do we need a guideline for quantitative FDG PET ?
0 1 2 3
Hospital
4.00000
8.00000
12.00000
16.00000
SUV
51-6
1 m
in n
orm
alis
ed to
wei
ght s
can
1
Recent (2009) observation on site differences in SUV-Site 1 & 2 closely followed NL standardised
protocol-Site 3 did not –
almost a factor of 2 lower SUV on average
FDG PET and PET/CT: EANM Procedure Guidelines for Tumour
PET Imaging: version 1.0
Ronald Boellaard, Mike O’Doherty, Wolfgang A. Weber, Felix M. Mottaghy, Markus N. Lonsdale, Sigrid G. Stroobants, Wim
J.G. Oyen, Joerg
Kotzerke, Otto S. Hoekstra, Jan Pruim, Paul K. Marsden, Klaus Tatsch, Corneline
J. Hoekstra, Eric.P. Visser, Bertjan
Arends, Fred J. Verzijlbergen, Josee
M. Zijlstra, Emile FI Comans, Adriaan
A. Lammertsma, Anne M. Paans, Antoon
T. Willemsen, Thomas Beyer, Andreas Bockisch, Cornelia Schaefer-Prokop, Dominique Delbeke, Richard P. Baum, Arturo Chiti, Bernd J. Krause.
Eur.J.Nucl.Med.Mol.Imag. 2010
Thank
you
for
your
attention
!