Clinical Trial Details
— Status: Terminated
Administrative data
NCT number |
NCT00633958 |
Other study ID # |
05-303 |
Secondary ID |
|
Status |
Terminated |
Phase |
Phase 1
|
First received |
|
Last updated |
|
Start date |
March 2008 |
Est. completion date |
March 2010 |
Study information
Verified date |
October 2021 |
Source |
Dana-Farber Cancer Institute |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
In spite of numerous advances in neuroimaging techniques, the diagnosis of pediatric brain
tumors relies on the pathologic evaluation of material obtained at the time of the initial
operation. While 18F-FDG-positron emission tomography (PET) helps identify higher-grade
lesions due to their increased glucose metabolism, the high tracer uptake of the normal
adjacent brains makes this modality of limited value. Fluorine-18 fluorothymidine (FLT) is a
new imaging agent that has two significant advantages in the imaging of CNS tumors. First,
this agent detects cellular proliferation directly, and second, the normal brain does not
take up the agent, making a positive area(s) easy to identify. Before embarking on a large
pediatric disease stratified assessment of FLT imaging in pediatric neurooncology patients,
the investigators are proposing a limited patient pilot study to evaluate the
biodistribution, dosimetry and specificity of this compound when compared to
immunohistochemical assessment of mitotic activity in newly diagnosed patients undergoing
surgical resection.
Description:
Patients will undergo standard pre-diagnostic imaging of the sites of disease using standard
MRI techniques. If disease is suspected in both the brain and spine, then both imaging
modalities should be obtained. This imaging should be obtained no more than 21 days before
surgical resection. As close as possible to the completion of the MRI scans, patients will
undergo 18F-FLT imaging using a single administration of tracer, and PET image acquisition at
four different time points (baseline, 1 hr post injection, 2 hrs post injection and 4-6 hours
post injection). A whole body PET scan (top of the head to mid thigh) will be performed
immediately after injection (PET acquisition #1). These data will be acquired with a 2 minute
emission and a 2 minute transmission scan at each bed position. Following this acquisition,
the subject will empty his or her bladder. At 45 minutes post-injection, a brain and/or spine
(body) PET scan will be acquired with a 10 min emission scan and a 5 min transmission scan
(PET acquisition #2). This scan will include all areas of suspected tumor (brain, spine, or
brain and spine). Following PET acquisition #2, a whole body PET scan will be acquired
according to the same protocol as above (PET acquisition #3). If possible, a final whole body
scan will be acquired 4-6 h post-injection (PET acquisition #4). All PET acquisitions will be
acquired in 3D mode and reconstructed with the FORE re-binned OSEM algorithm with measured
attenuation correction. Blood samples will be obtained at the completion of each whole body
scan. Patients will receive the dose of 18F-FLT through a fresh intravenous catheter as per
standard PET procedures. Patients will then undergo maximal surgical resection. Pieces from
different areas of the tumor will be marked for correlation to imaging studies when possible.
Tumor samples will undergo standard immunohistochemical analysis for cellular activation
including mitotic index and MIB-1 proliferation staining.
Serial blood draws will also be obtained at four different time points (baseline, 1 hr post
injection, 2 hrs post injection, and 4-6 hours post injection) to evaluate clearance of
18F-FLT from the blood.
For the biodistribution, the 3D regions of interest (ROIs) will be drawn about each major
organ that is identified on the whole body scans. This will be performed on each of the whole
body scans and a time activity curve will be generated. The residence time for each organ
will be determined. The blood data will be pipetted and counted for estimates of activity in
the blood and bone marrow. For the brain and/or spine images, the PET data will be registered
to the subjects' MRI. The PET scan will be graded on a subjective 4-point scale. 3D ROIs will
be drawn around the tumor. In addition, an analogous ROI will be drawn in normal brain
background and about the whole brain for comparison. For the tumor, tumor-to-background,
tumor-to-whole brain ratios will be determined. In addition, standard uptake values (SUVs)
will be determined for the tumor and background.