N A GRADING SCHEME FOR COMBINED SOMATOSTATIN RECEPTOR (SSR) & FDG IMAGING Dale L Bailey David LH...
-
Upload
mariah-hensley -
Category
Documents
-
view
220 -
download
4
Transcript of N A GRADING SCHEME FOR COMBINED SOMATOSTATIN RECEPTOR (SSR) & FDG IMAGING Dale L Bailey David LH...
N
A GRADING SCHEME FOR COMBINED SOMATOSTATIN
RECEPTOR (SSR) & FDG IMAGING
Dale L BaileyDavid LH ChanGeoffrey P SchembriElizabeth J BernardNick PavlakisPaul J Roach
ANZNET
Departments of Nuclear Medicine & Medical Oncology Royal North Shore HospitalFaculty of Health Sciences & Sydney Medical School University of Sydney
Sydney Vital (Northern Translational Cancer Research Centre)Sydney AUSTRALIA
ANZNET[68Ga]-DOTA-Octreotate
(“DOTATATE”)[18F]-FDG
COMBINED SSR & FDG PETSCANNING IN NETs
ANZNET
[18F]-FDG
EXAMPLE SCAN REPORTS
SCANNED 1 DAY APART
REPORTED BY SAME SPECIALIST
NO MENTION OF OTHER SCAN IN EITHER REPORT
NO INDICATION IF THE SAME LESIONS ARE BEING CONSIDERED
NO MENTION OF HOW UPTAKE CORRELATES SPATIALLY
REPORT SUGGESTIVE OF PARTIAL RESPONSE - IS THE DISEASE CHANGING?
[68Ga]-DOTA-Octreotate(“DOTATATE”)
ANZNET
COMBINED SSR & FDG IMAGING
SSR (DOTATATE) +ve IMAGING
• Reflects well-differentiated disease
• Well suited to targetting with radiolabelled SSR therapy
• What is the significance of the degree of uptake (e.g., SUVmax)?
• What is the reproducibility of uptake?
• Is uptake affected by competing agents?
• Role in reflecting likely rate of disease progression?
FDG +ve IMAGING
• Reflects degree of de-differentiation / Ki67
• Often invoked when Ki67 from the primary lesion or a biopsy exceeds a threshold (3%, 5%, 10%, 20%, etc) – based on NET Grading (G1, G2, G3)
• High FDG uptake with low SSR uptake indicates disease may be less amenable to radiolabelled SSR therapy - chemo/biologics may be more suitable
• Represents more aggressive disease & poorer prognosis
• Pathology may not reflect varying disease differentiation throughout the body
ANZNET
The NETPET Grading Scheme - AIMS
› To summarise the results of the two scans in a single score which captures the joint information available – especially to assist referrers;
› To grade the scans by spatial concordance and relative uptake;
› To develop a grading scheme for combined SSR and FDG PET imaging that gives an indication of the subject’s suitability for radionuclide SSR-based therapy based on the scan findings;
› To try to improve consistency and standardisation of reporting of the two scans:- between contemporaneous SSR and FDG scans;- over time;
› To recognise the complementary intrinsic biological signals present in each scan;
› To allow for easier summarising of scan results for data mining in translational research;
› To see whether the grading scheme has a role in prognosis.
NETPET Grading Scheme*
P0 P1 P2 P3 P4 P5
SSR -ve
FDG -ve
SSR +ve
FDG -ve
SSR -ve
FDG +ve
SSR +ve
FDG +ve
FDG uptake < SSR uptake
FDG uptake SSR uptake
FDG uptake > SSR uptake
SSR +ve
FDG +ve
SSR +ve
FDG +ve
ANZNET
*With image display thresholds set at: SUVmax(DOTATATE) = 15SUVmax(FDG) = 7
ANZNETANZNET
ANZNETANZNET
METHODS
› In the period 2011-2015 we performed n=186 [68Ga]-DOTATATE and [18F]-FDG scans on the same individuals (n=125) within 28 days;
› All scans acquired on Siemens Biograph mCT with Time-of-Flight capability and resolution recovery software using an iterative OSEM reconstruction;
› A cohort of subjects diagnosed as having primary pancreatic NET (pNET) were selected for pilot evaluation (n=30):
- these are the results being presented today;
› Two experienced NM physicians independently scored the DOTATATE/FDG scan pairs, with all clinical information available, & graded them according to the flowchart;
› After the scans were read independently the two reporters conferred to check each other’s gradings.
[68Ga]-DOTA-Octreotate [18F]-FDG
RS 1578506
P1 P2 P3 P4 P5P0
SSR -ve
FDG -ve
[68Ga]-DOTA-Octreotate [18F]-FDG
SB 1624411
P1 P2 P3 P4 P5P0
SSR +ve
FDG -ve
More likely to benefit from
Lutate Rx
[68Ga]-DOTA-Octreotate [18F]-FDG
LB 0393073
SSR -ve
FDG +ve
Less likely to benefit from
Lutate Rx
[68Ga]-DOTA-Octreotate [18F]-FDG
MU 1694996
P1 P2 P3 P4 P5P0
P2aFDG uptake < SSR uptake
1-2 lesionsFDG < SSR
More likely to benefit from
Lutate Rx
[68Ga]-DOTA-Octreotate [18F]-FDG
SF 0351903
P2b3 lesions
FDG < SSR
More likely to benefit from
Lutate Rx
SSR scan +veFDG scan +ve
No lesionsFDG +veSSR -ve
[68Ga]-DOTA-Octreotate [18F]-FDG
DC 1687299
P1 P2 P3 P4 P5P0
P3aFDG uptake SSR uptake
1-2 lesionsFDG SSR
More likely to benefit from
Lutate Rx
[68Ga]-DOTA-Octreotate [18F]-FDG
RB 1678868
P3b3 lesions
FDG SSR
More likely to benefit from
Lutate Rx
SSR scan +veFDG scan +ve
No lesionsFDG +veSSR -ve
[68Ga]-DOTA-Octreotate [18F]-FDG
GM 1062450
P1 P2 P3 P4 P5P0
P4aFDG uptake > SSR uptake
1-2 lesionsFDG > SSR
More likely to benefit from
Lutate Rx
[68Ga]-DOTA-Octreotate [18F]-FDG
XW 1644491
P4b3 lesions
FDG > SSR
Less likely to benefit from
Lutate Rx
SSR scan +veFDG scan +ve
No lesionsFDG +veSSR -ve
[68Ga]-DOTA-Octreotate [18F]-FDG
P1 P2 P3 P4 P5P0
JP 0314628
2 lesionsFDG +ve / SSR -ve
Lesions present includeFDG +veDOTA -ve
Less likely to benefit from
Lutate Rx
RESULTS – pNETs ONLY
Grade Number Lutate Rx?
P0 4 0
P1 3 0
P2a 2 0
P2b 9 1
P3a 2 1
P3b 1 1
P4a 3 2
P4b 2 1
P5 4 0
TOTAL 30 6
(XW)
RESULTS – pNETs ONLY
n=4
n=22
n=4
Survival (months)0 16 32 48
P=0.014 by logrank test for trend (Bland JM & Altman DG. The logrank test. BMJ. 2004;328:1073)
Grade Changing
[68Ga]-DOTA-Octreotate [18F]-FDG [68Ga]-DOTA-Octreotate [18F]-FDG
Mar 2015 - P4a July 2015 - P2a 2 cycles Lutate
KG 1487636
DISCUSSION
› Only small numbers to date and limited follow-up period;
› Does the grading scheme adequately reflect the burden of disease?;
› Do we know the significance of SUV (or uptake level) for SSR imaging?:
- for the present should [68Ga]-DOTATATE be graded with a binary score (Y/N)?;
› Do we need to add more information regarding the bulk of disease for the primary lesion? Or perhaps include a TNM system?
ACKNOWLEDGEMENTS• David Chan is a research fellow funded in part by Sydney Vital (Cancer Institute NSW);• Nick Pavlakis & Dale Bailey are co-leaders of the “NETwork” flagship project of Sydney Vital which receives funding from Cancer Institute NSW.
› How to deal with intra-lesional heterogeneity;
› Dos the classification scheme predict for Lutate efficacy?
› Will the classification scheme have prognostic value?
› How will the classification compare with other grading schema?
FDG
DOTATATE
GM 1062450