PET Phantom Program
CTN oncology chest phantom scan demonstrating how lesions appear in the chest. Image shows a single slice rendering of the phantom.
Courtesy, Paul E. Christian, Huntsman Cancer Institute, University of Utah.
When pharmaceutical companies apply to the Food and Drug Administration (FDA) for approval of a new product, they must first demonstrate a certain level of disease detectability as evidenced by some imaging measurement. Many of the denials of new drugs are based on a rejection of data compiled from poor-quality images or images that don't appear to match those from another similar study.
A key component of the SNM Clinical Trials Network (the Network) registry will be to ascertain and sustain the qualification of each of the many centers involved through a demonstration of the ability to acquire high-quality images as well as interpret them. Toward this end, SNM will rely on its long-established imaging Phantom Program. Phantoms, with a known quantity and distribution of activity, will be used to evaluate each site's imaging capabilities and ensure standardization and compliance with defined protocols in order to assure consistency across multiple centers in a single trial.
A goal of the Network is to be able to ensure that all participating sites in a particular trial meet the necessary image quality and ability to detect disease. An important aspect of any multicenter clinical trial involving an imaging modality is ensuring that the equipment used in the various locations is capable of acquiring images in a standardized fashion that is similar to the other locations participating in the trial.
Prior to participating in one of SNM's multicenter clinical trials, sites will be required to demonstrate their ability to provide evidence of image quality and disease detectability. Once they follow the phantom-imaging instructions and electronically forward their results to SNM, an evaluation will be made based on image quality and the correct findings; for example, the correct number and location of lesions. If a center doesn't meet criteria, they will be given an opportunity to recalibrate and try again.
For the Network registry, the Quality Assurance Committee (QAC) has designed a PET chest phantom that contains simulated lesions in a variety of locations. Sites will image the phantom and return these to the QAC for evaluation. The SNM Phantom Program provides a distinct advantage in that it is made up of a group of experts who know what to look for when evaluating a center's image quality and can recommend adjustments in the image acquisition parameters to produce images of a very high quality.
SNM has a long history of testing nuclear medicine imaging quality by designing clinical simulators (phantoms) and evaluating how an imaging center acquires, processes and displays images, as well as how successfully physicians interpret them. SNM has provided phantoms for site certification for a number of years and currently make phantoms available to the U.S. Department of Veterans Affairs to evaluate more than 135 VA hospitals and pinpoint equipment and procedure problems. SNM experts then offer these hospitals and laboratories solutions to improve and meet credentialing requirements.
Standardization of adherence to protocols and harmonization of results is critical to compiling a body of significant data and, ultimately, to obtaining FDA approval. SNM's Phantom Program is already demonstrating its ability to establish compatibility in image quality and, therefore, present significant results.
SNM's Phantom Program offers a substantial enhancement toward ensuring that the FDA will accept the Network's data, which is a major hurdle in drug approval.
Frequently Asked Questions
Q. I note that participation of centers outside North America is encouraged. How is their participation in the phantom program being envisioned?
A. The current plans are to run the phantom program in the same way for Europe and the U.S. Essentially, the process is that the phantom will be shipped to a site with clear filling and imaging protocol instructions. The site will image the phantom and return the images to a review committee for either approval or further recommendations. Final details as to whether there will be a single review committee, or more than one – with one based solely in Europe – have not been decided at this time.
Q. Is there a purchase cost, or a rental cost, for the performance phantom that is required for all registered members of the Clinical Trials Network?
A. The phantom program is made available to all sites who register for the Network. There is no requirement to purchase the phantom. It will be provided to your site for qualification tests, and then you will return it to SNM. The SNM phantom is not for sale. Currently, there are no plans to charge for participation in the SNM Clinical Trials Network phantom program.
LAST UPDATED: 6/29/2010