An Exploration of Gated and Non-Gated Dynamic PET/CT Imaging
Phase: NA
Conditions: Dynamic PET/CT Imaging
Sponsor: Washington University School of Medicine

Protocol Title:   
An Exploration of Gated and Non-Gated Dynamic PET/CT Imaging 
 
NCT#:  
 
NCT04283552 
 
Version Date:  
11/20/2020 

 
 
 
An Exploration of Gated and Non-Gated Dynamic PET/CT 
Imaging 
 
Protocol Version: 1.2 
HRPO #: 201910076 
Version Date: 11/20/2020 
 
 
Principal Investigator 
Richard L Wahl, MD 
Professor of Radiology and Radiation Oncology 
Chairman: Department of Radiology 
Director: Mallinckrodt Institute of Radiology 
Washington University School of Medicine  
Telephone: (314) 362-7100 
Email: rwahl@wustl.edu  
 
Sub-Investigators 
Tyler J Fraum, MD 
Assistant Professor of Radiology 
Mallinckrodt Institute of Radiology 
Washington University School of Medicine  
Telephone: (314) 362-2928 
Email: tylerjfraum@wustl.edu  
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
I. 
Background 
Positron emission tomography / computed tomography (PET/CT) imaging has 
become a crucial tool in the diagnosis, staging, and restaging of cancer 
patients (1,2,3). PET/CT imaging is generally performed by imaging a patient, 
following an uptake phase, after administration of a radiotracer, most 
commonly 18F-fluorodeoxyglucose (FDG) (4). This 'uptake' period allows time 
for the radiotracer to accumulate in areas of interest and for a reduction in the 
ratio of normal tissue uptake to the uptake in tissue with disease. However, 
the uptake periods used in clinical protocols are somewhat arbitrary and are 
not expected to be optimal for all clinical cases. Dynamic tracer imaging 
during the uptake phase can provide considerably more information by 
delineating both the temporal and spatial pattern of tracer uptake. Dynamic 
imaging allows calculation of tissue uptake rate, whereas from static imaging 
only magnitude of tissue uptake can be calculated. In addition, several 
potential sources of error that occur in static imaging may be mitigated (5). 
 
In order to fully assess the utility of dynamic PET imaging, an understanding 
of the test-retest repeatability of dynamic imaging is necessary. Generally, the 
standardized uptake value (SUV), a semi-quantitative measure of PET 
radiotracer uptake, has been shown to be a highly repeatable imaging 
biomarker (6). In recurrent ovarian cancer patients, one study found FDG 
uptake measurements to have repeatability coefficients of 16.3% and 17.3% 
for SUVmean and SUVmax, respectively (7). Using a mouse model, 
Whisenant et al found kinetic parameters extracted from dynamic PET 
images were sufficiently repeatable to be used for therapy response 
assessment (8). While several human studies have indicated PET metrics 
extracted from dynamic PET images also show a high degree of test-retest 
reliability, a complete evaluation of dynamic PET repeatability remains 
incomplete (9, 10, 11). 
 
Since PET/CT imaging (dynamic or static) is performed over an extended 
period of time, patient motion (particularly respiratory motion) is inevitable and 
can cause significant image artifacts (12). Volume and SUVmax (vital metrics 
in PET/CT imaging) have been shown to be significantly impacted by 
movement during imaging. Motion has been shown to cause an 
underestimation of SUVmax by as much as 28% and an overestimation of 
volume by up to 130% (13). Different methods have been developed to 
manage the respiratory motion problem including breathhold procedures (14), 
respiratory gating (15), and other post-processing techniques (16). 
Respiratory gating involves sorting the PET data into different bins with 
respect to the respiratory status. Each bin thus contains only a part of total 
motion and will have reduced motion artifacts. Unfortunately, the bins contain 
only a part of the total number of events detected in the scanner, which leads 
to more noise. OncoFreeze is a novel approach to PET motion correction that 
utilizes 100% of events, which are corrected to an optimal gate image utilizing 

 
 
 
an optical flow algorithm, creating the potential for motion corrected images 
without increasing image noise.  
 
 
II. 
Objectives 
 
1. Assess the technical feasibility of dynamic, whole-body multiparametic PET 
imaging 
2. Assess the quantitative and clinical impacts of a novel approach to PET 
data motion correction (OncoFreeze), relative to more conventional static and 
respiratory-gated PET images. 
3. Quantify the test-retest repeatability of quantitative metrics extracted from 
dynamic PET images. 
4. Comparision of the early and late Patlak images to determine the optimal 
post-injection time period for dynamic PET imaging for Patlak analysis. 
 
 
III. 
Eligibility 
 
Main Cohort: Any patient 18 years of age or older, scheduled to undergo a 
clinical PET/CT scan with any clinically prescribed radiotracer* for known or 
suspected malignancy (pathologic confirmation not required), and able to 
provide informed consent is eligible to participate in this study.  
 
Repeatability Cohort: Any patient 18 years of age or older, scheduled to 
undergo a clinical PET/CT scan with FDG or 68Ga- DOTA-0-Tyr3-Octreotate 
(DOTATATE) for known or suspected malignancy (pathologic confirmation 
not required), and able to provide informed consent is eligible to participate in 
this study. 
 
*NOTE: Some patients are evaluated clinically with multiple radiotracers prior 
to therapy. Patients scheduled to undergo multiple PET/CT imaging 
procedures will be eligible to have dynamic imaging performed during each of 
these procedures. However, these patients would only be eligible to have 1 
repeat imaging procedure for research purposes. 
 
IV. 
Patient Registration 
Patients must not start any protocol intervention prior to registration through 
the Siteman Cancer Center.  
The following steps must be taken before registering patients to this study:  
1. Confirmation of patient eligibility  
2. Registration of patient in the Siteman Cancer Center database  
3. Assignment of unique patient number (UPN)  

 
 
 
 
Confirmation of Patient Eligibility  
Confirm patient eligibility by collecting the information listed below:  
1. Registering MD’s name  
2. Patient’s race, sex, and DOB  
3. Three letters (or two letters and a dash) for the patient’s initials  
4. Copy of signed consent form  
5. Completed eligibility checklist, signed and dated by a member of the study 
team  
6. Copy of appropriate source documentation confirming patient eligibility  
 
Patient Registration in the Siteman Cancer Center Database  
All patients must be registered through the Siteman Cancer Center database.  
 
Assignment of UPN  
Each patient will be identified with a unique patient number (UPN) for this 
study. All data will be recorded with this identification number on the 
appropriate CRFs. 
 
V. 
Patient Compensation 
Patients will be compensated for their participation in this study. Upon 
successful completion of the study, patients will be paid $50.00 and given a 
parking voucher, if necessary, for research imaging performed on the day of 
their clinical scan. Patients who participate in a retest imaging session will be 
paid an additional $150.00, as well as a parking voucher, if they drove to 
campus. 
 
 
VI. 
Methods 
Main and Repeatability Cohorts 
 
This protocol seeks to evaluate: (1) Metrics derived from dynamic positron 
emission tomography / computed tomography (PET/CT) imaging, (2) methods 
for achieving motion correction of PET/CT images, and (3) the repeatability of 
dynamic imaging. Clinical PET/CT imaging is normally performed by injecting 
a patient with a radiopharmaceutical (most commonly FDG) and collecting 
images using a PET scanner (preceded by a brief CT scan) after an uptake 
phase, which varies in duration depending on radiotracer. The data for this 
study will mostly be collected by asking patients to have PET images 
collected during the uptake phase (preceded by a low-dose research CT 
scan) in addition to the normal clinical images. We will also ask them to 
remain in the scanner for up to 20 minutes following the clinical scan in order 
to perform additional research PET imaging. The normal clinical scan 
(including radiation dose) will not be impacted by this study. However, the 
low-dose CT performed prior to the dynamic imaging will result in additional 
radiation exposure. All scans will be performed on a Siemens Vision scanner. 

 
 
 
Ideally, participants will be positioned in the same way they’ll be positioned for 
their clinical scan. However, as the research imaging takes a considerable 
amount of time, patients may be positioned differently (e.g. with arms by their 
sides) if the clinically-indicated position would prove too difficult. 
 
Repeatability Cohort Only 
 
A subset of patients (up to 30 scheduled to undergo FDG or DOTATATE 
PET/CT imaging) will be asked to return to the CCIR within 7 days for a 
repeat imaging study. This time-point will involve the same procedures 
performed during the initial imaging visit.  
 
Study Procedures 
 
Following the consent process, patients will be escorted to the PET/CT 
imaging suite where they will be positioned on the imaging bed. As part of the 
routine clinical PET/CT procedure, an IV will be placed. A low-dose CT will 
then be performed, followed by the administration of the [clinically-prescribed] 
radiotracer. Immediately following the tracer administration, PET imaging will 
begin and continue for approximately 40 - 60 minutes at which point the 
clinical PET/CT procedure will be performed. Patients will be asked to use the 
bathroom between the research and clinical imaging. 
 
 
Specific Dynamic Imaging Procedure 
1) Upon arrival, patients will be taken to a preparation room where they will 
be kept warm and they will have time to review the consent form and ask 
any questions they might have about the dynamic imaging study. 
2) Patients will be asked to void immediately prior to the start of PET/CT 
imaging. 
3) Patients will then be escorted to the scanner and have one IV placed.  
4) A low-dose CT will be performed. 
5) A single weight-based dose of a radiotracer will be administered.  
6) Patients should be positioned comfortably so as to reduce the likelihood of 
movement during the scan.  
7) Dynamic PET/CT imaging (utilizing multiple whole-body passes) will begin 
immediately following the radiotracer injection and will continue until 
approximately 10 – 20 minutes prior to the start of the clinical scan. These 
passes will be used to generate early Patlak images. 
8) Upon completion of the dynamic scan, patients will be asked to use the 
bathroom to empty their bladders, and then the clinical scan procedure will 
begin. 
9) During the clinical scan procedure, patients will wear an Anzai belt, a 
device that tracks respiratory motion.  
10) Following the clinical imaging, patients will remain in the scanner for 
approximately 20 minutes while additional research PET images are 

 
 
 
collected. These additional passes will enable the generation of late Patlak 
images for comparison with early Patlak images. 
 
Repeat Dynamic Imaging 
Patients who agree to participate in the repeatability sub-study will be asked 
to return to the CCIR within 7 days for an additional imaging study. This visit 
will involve the same procedures as the initial imaging visit and will be 
performed entirely for research purposes. The repeat visit should include 
approximately the same radiotracer and CT doses. In the case of imaging 
delays (i.e. an uptake time differing significantly from what is clinically 
recommended) during the initial imaging visit, the same delay should be 
incorporated into the repeat imaging visit. 
 
 
 
VII. 
Data Analysis 
The primary endpoint of this prospective study is the feasibility of 
multiparametric PET in a general oncology population. A total of 75 subjects 
will be recruited for the multiparametric PET portion of the study. If we 
observe a successful completion rate of 81.3% (i.e., 61 of 75 subjects), the 
exact 95% confidence interval for that proportion and sample size would be 
71-89%. The lower limit of this confidence interval will effectively indicate that 
the true successful completion rate is highly likely to be ≥70% and that 
multiparametric PET is feasible in a general oncology population.  
 
Primary aim: The feasibility of rapid, whole-body dynamic PET imaging will 
be assessed by evaluating the practicality of acquiring dynamic PET data in 
the clinic. The feasibility of multiparametric PET for oncologic imaging will be 
defined as successful completion of the study imaging component in at least 
70% of cases. Successful completion of the study imaging component will be 
defined as: (1) patient remains on scanner for the full dynamic phase of PET 
imaging prior to the standard-of-care PET/CT and (2) automated scanner 
software is able to successfully generate valid parametric maps (requires at 
least three consecutive whole-body PET acquisitions without substantial 
motion between acquisitions). Feasibility is important to establish due to the 
added demands on patients arising from the long imaging period. In addition, 
novel quantitative metrics derived from dynamic PET acquisitions will be 
compared with standard semiquantitative metrics, such as SUV and 
metabolic tumor volume (MTV), obtained from the clinical PET/CT scan. 
 
Secondary aim #1: The quantitative and clinical impacts of OncoFreeze 
(specifically, on semi-quantitative SUV metrics and on the number of 
detectable lesions) will be assessed by comparing motion-corrected images 
derived from OncoFreeze with standard static non-gated PET images and 
conventionally gated PET images. Two independent readers blinded to the 

 
 
 
reconstruction approach will score image quality utilizing a standard Likert-
type scale and will extract quantitative metrics (e.g., SUV-max, SUV-peak) for 
any apparent FDG-avid lesions. Results will be compared for (1) motion-
corrected images derived from OncoFreeze, (2) standard static non-gated 
PET images, and (3) conventionally gated PET images. 
 
Secondary aim #2: The repeatability of dynamic imaging will be evaluated by 
calculating the measurement agreement and relative differences in semi-
quantitative PET metrics between test and retest dynamic images. Imaging 
metric agreement will be measured using Bland-Altman analysis. Groupwise 
differences between imaging time-points will also be assessed using t-tests or 
Mann-Whitney U tests, depending on normality. 
 
Secondary aim #3: The early and late Patlak images (specifically: metabolic 
rate [slope] and volume of distribution [intercept] images) will be compared in 
a head-to-head fashion, both qualitatively and quantitatively. This aim will 
help to determine the optimal post-injection time period for dynamic PET 
imaging for Patlak analysis. 
 
 
VIII. 
Study Risks and Benefits 
1) IV Risks: 
The risks from IV placement include bruising, pain, or infection at the 
injection site and possible leaking of IV fluid into nearby tissues. The risk 
of infection is quite low. There is a moderate risk of pain or bruising. 
Intravenous injections will be performed only by experienced staff and a 
physician will be available throughout the procedure in case of any 
infusion side effects. 
2) FDG Risks: 
FDG is FDA-approved and known to be very safe. There are few known 
side-effects associated with FDG.  In a large cohort, less than 1% or less 
of patients experienced transient hypotension, hypo- or hyperglycemia, or 
transient increases in alkaline phosphatase. The package insert for FDG 
lists no warnings, interactions, or precautions. A review of the literature 
reveals no adverse effects.  
3) DOTATATE Risks: 
Risks associated with DOTATATE were assessed in 3 clinical trials and 
no serious adverse events were reported. In a small percentage of 
patients, nausea and/or vomiting have been reported following the 
administration of DOTATATE. 

 
 
 
4) Radiation Risks: 
This research involves exposure to radiation from PET/CT imaging.  As 
part of the repeatability cohort, patients will receive 1 radiotracer dose 
(either FDG or DOTATATE) and 3 low-dose CTs as part of the research 
procedures. The risk from the radiation exposure in this study is too small 
to be measured.  It is not a big risk when compared with other risks you 
take every day.  For more information about radiation exposure, please 
see the “Radiation Fact Sheet” at 
https://hrpo.wustl.edu/participants/radiation-fact-sheet. 
5) PET/CT Imaging Risks: 
Patients may experience some discomfort having to lie still for an 
extended period of time. Patients who dislike small spaces may also find 
the PET/CT scanner uncomfortable. 
 
IX. 
Regulatory and Reporting Requirements 
The Principal Investigator is responsible for ensuring the safety of subjects who 
have enrolled in the study.  The PI will monitor the study for adverse events 
directly attributable to participation in this study (i.e. events associated with the 
additional research PET/CT imaging, not events associated with the clinical 
PET/CT imaging, including radiopharmaceutical administration).  If any breach 
of confidentiality were to occur, it would be reported according to the HRPO-
recommended guidelines. 
 
Reporting 
Based on the half-lives of the tracers involved in this study, adverse event 
tracking will be performed for 24 hours starting at the time of radiotracer 
administration. Any reported events, anticipated or unanticipated, will be 
reviewed by the PI and reported per the WUSTL HRPO guidelines.  These 
events will be followed until resolution. 
 
Study deviations will be tracked and recorded throughout the study.  Any 
serious deviations will be reported immediately to the IRB.  Otherwise, study 
deviations will be reviewed by the PI and reported on an annual basis. 
 
X. 
Data and Safety Monitoring Plan 
The principal investigator will review all patient data at least every six months, 
and provide an annual report to the QASM Committee. This report will include 
1. the protocol title, IRB protocol number, and the activation date of the study. 
2. the number of patients enrolled to date 3. the date of first and most recent 

 
 
 
patient enrollment 4. a summary of all adverse events regardless of grade 
and attribution 5. a response evaluation for evaluable patients 6. a summary 
of any recent literature that may affect the ethics of the study. The study 
principal investigator and clinical research associate will monitor for serious 
toxicities on an ongoing basis. Once the principal investigator or clinical 
research associate becomes aware of a serious adverse event, the SAE will 
be reported to the HRPO and QASM Committee [add other reporting 
requirements here if applicable, e.g. sponsor, FDA, collaborating institutions] 
within 10 working days. 
 
Adverse Events 
For the purposes of this protocol, an adverse event (AE) is any untoward 
medical occurrence within 24 hours of radiotracer administration (e.g., sign, 
symptom, disease, syndrome, intercurrent illness, abnormal laboratory 
finding) that emerges or worsens relative to pre-imaging baseline.  The 
Investigators will monitor the occurrence of adverse events during the course 
of the study.  The Investigators need to assess whether there is a reasonable 
possibility that the study imaging agent caused or contributed to an AE using 
the following criteria as a guide: 
  
Definite:  The adverse event is clearly related to the imaging procedure. 
Probable:  There is a clinically plausible time sequence between the onset of 
the AE and administration of imaging tracer.  The AE is unlikely to be caused 
by the concurrent/underlying illness, other drugs, or procedures.  
Possible:  There is a clinically plausible time sequence between the onset of 
the AE and administration of imaging tracer, but the AE could also be 
attributed to the concurrent/underlying disease, other drugs, or procedures.  
“Possibly” should be used when the administration of the study imaging tracer 
is one of several biologically plausible causes of the AE. 
Unlikely:  The adverse event is doubtfully related to the imaging procedure. 

 
 
 
• Not Related:  Another cause of the AE is the most plausible and/or a 
clinically plausible temporal sequence is inconsistent with the onset of 
the AE and the imaging procedure; and/or a causal relationship is 
considered biologically implausible. 
If any adverse event is considered to be definitely, possibly or probably 
related to the investigational imaging tracer, that event will be followed 
until resolution or until it is deemed chronic or irreversible by the 
Investigator.  If an event is unlikely or not related to the investigational 
imaging tracer, the event will not be reported. 
All adverse effects will be documented and recorded in the medical record 
and will include: 
• Specific reaction according to NCI Common Toxicity Criteria, version 
4.0. 
• Duration of the reaction 
• Severity/grade according to NCI Common Toxicity Criteria, version 4.0. 
If the adverse event is not addressed by the Common Toxicity Criteria, 
the severity should be rated as mild (grade 1), moderate (grade 2), 
severe (grade 3), or life threatening (grade 4). 
• Relation of reaction to study agent 
• Management of reaction, including any interruption or dose 
modification of the study drugs. 
 
Event Types 
The term “adverse event” is defined in the International Conference on 
Harmonization Guideline for Good Clinical Practice as follows:  
“Any untoward medical occurrence in a patient or clinical investigation subject 
administered a pharmaceutical product and which does not necessarily have 
a causal relationship with this treatment.  An adverse event (AE) can 
therefore be any unfavorable and unintended sign (including an abnormal 
laboratory finding), symptom, or disease temporally associated with the use of 
a medicinal (investigational) product whether or not related to the medicinal 
(investigational) product”.  

 
 
 
Medical conditions of a subject that exist prior to receiving the investigational 
imaging tracer will be recorded as medical history.  After administration of the 
investigational imaging tracer, all new medical conditions are considered 
adverse events.  Adverse events occurring in this trial will be recorded in data 
collection forms, regardless of whether or not they are thought to be 
associated with the investigational imaging tracer throughout the study period 
(From the time of consent until the completion of the repeat PET/MR scan).  
However, the Investigator also will assess the possible relationship between 
the adverse event and the investigational imaging tracer. 
Serious Adverse Events 
Any adverse drug experience, occurring at any dose that results in any of the 
following: 
• 
Death 
• 
Is life-threatening (an event in which the patient was at immediate 
risk of death; it does not refer  to an event which hypothetically might have 
caused death if it were more severe) 
• 
Requires or prolongs inpatient hospitalization  
• 
Results in a persistent or significant disability/incapacity 
• 
Is a congenital anomaly/birth defect 
• 
Important medical events that may not result in death, be life-
threatening, or require hospitalization may be considered serious 
when, based upon appropriate medical judgment, they may jeopardize 
the patient or subject and/or may require intervention to prevent one of 
the outcomes listed. 
All other AEs will be treated as “non-serious” and are described in the final 
study report.  An SAE that is definitely, probably or possibly related to the 
investigational imaging tracer will be reported immediately by telephone or fax 
to the Principle Investigator. 
 
 
XI. 
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