In the world of pharmaceutical drug development, if we were to build the perfect imaging clinical site, what would it be?
From the core lab perspective, the ideal site would have a blend of therapeutic experience, flexibility, and excellent communication
skills.
PAUL BURNS, GETTY IMAGES
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Sites with the most experience in the areas of modality, treatment, target population, and clinical trials are already a step
ahead of the pack. Based on our years of experience, these sites also tend to provide the highest quality data. Sites that
can effectively communicate with all the participating parties (i.e., sponsor, medical imaging personnel, imaging core lab,
and patient volunteers) are able to perform at more consistent levels and meet significant dates related to study timelines.
Not all clinical sites are held to the same rigor, nor should they be. It is difficult to expect an ophthalmology site to
be experts in acquiring ECGs for cardiac safety testing. So much depends on the type of study being conducted. But when a
protocol demands such expertise, it is imperative that the site be as perfect as possible.
For example, a site selected in an oncology clinical study where the Response Evaluation Criteria In Solid Tumors (RECIST)
will be used must be able to acquire imaging data that is usable for consistent measurements and observations by independent
reviewers. According to Janie Petti, assistant director of project management at Biomedical Systems, "Sponsors should select a clinical
site with strong expertise in the patient population of the disease state being targeted for the clinical trial. Asking the
right questions upfront in site surveys can provide sponsors with better information on the experience and capabilities of
sites."
Knowing how to operate the equipment is not enough. "Sites that are associated with imaging centers that have experienced,
registered technologists understand the importance of good image quality," said Petti. "The measures required to attain quality
imaging data defined by the protocol are second nature to them."
Once the data is acquired and transmitted by the site, high-end software programs are used by the reviewers to make the required
measurements per protocol specifications.
According to Ingrid Van Rompaey, PhD, associate director for project management in the Hematology and Oncology Therapeutic
Group for PPD in Brussels, Belgium: "It is essential that the imaging data be of sufficient quality to allow reviewers to
make exactly the same measurement each time the data is evaluated. For this reason it is important to have sites that can
comply with study specific protocols when the independent reviewers are using RECIST criteria."
Necessary criteria
Sites that acquire MRI images and use equipment with a 1.5 to 3.0 strength magnet will produce the highest quality imaging
data. The magnet strength has a direct relation to the pixel size of the data acquired. The smaller pixel size results in
clearer images and allows for more efficient use of the software tools utilized by the independent reviewers.
Sites are strongly recommended to use equipment that is accredited by the American College of Radiology (ACR). ACR accredited
equipment in good working order and operated by experienced technologists can prevent ghosting and other effects, which can
diminish image quality.
Imaging centers should have a radiologist on-site to evaluate the images while the patient is on the premises. For safety
and convenience, any issues with the image data can be quickly resolved and should not require rescheduling of patient(s)
involved in the study. If contrast is being used for MRI data, sites should have a Power Injector on site to facilitate the
protocol requirements. This will avoid any potential time point impacts or patient attrition.
According to Van Rompaey, the perfect site would have calibrated equipment to ensure the data the imaging center is provided
is consistently interpreted by the independent reviewer. To ensure this consistency, it is important that the site uses the
same modality and machine for a clinical trial subject throughout their enrollment in the study.
Computed Tomography (CT) imaging equipment tends to offer a wider spectrum of capabilities. Sites that can meet the stricter
protocol requirements are preferred, as this will reduce variability between independent reviewers. If the protocol calls
for a 5mm slice thickness, the perfect site would be able to acquire image data that meets the specification.
With the availability of newer CT equipment and added experience with clinical trial requirements, imaging centers associated
with academic research sites tend to produce data that is of higher quality. These sites also tend to follow processes that
result in a reduced number of queries, according to Chris Schaefer, director of operations at Biomedical Systems.
So as we continue to build our "perfect" site, it will have the latest generation of CT equipment, follow the imaging protocol,
and deliver the imaging data to the core lab within the time constraints detailed in the protocol.
Electronic imaging data in native DICOM format is important to the transfer and integrity of high-quality CT imaging. DICOM
transferred data will maintain its quality should any postprocessing, 3D or multiplan reconstruction be required. The header
of the DICOM data will reveal the parameters used to create the images.
