Development and Implementation of a Radiation Safety Screening Protocol for a Clinical Study Using Amyloid Positron...

Amyloid positron emission tomography (PET) is gaining popularity for clinical and research purposes, particularly since the US Food and Drug Administration approval of anti-amyloid therapies. While the benefits of PET imaging in clinical care outweigh the risks associated with radiation exposure, the risks from elective radiation exposure in research should be carefully considered. Currently, no published or widely used guidelines consider prior radiation exposure as part of the eligibility determination for prospective participants in a clinical trial that includes ionizing radiation exposure.

We reviewed the medical literature and current studies listed on ClinicalTrials.gov for radiation safety criteria and study protocols that include amyloid PET scans. We then developed a safety screening procedure to systematically estimate prior radiation exposure to determine eligibility for participation in an amyloid PET substudy and implemented this procedure in the Successful AGing after Elective Surgery (SAGES) study.

Of the studies including amyloid PET that were listed on ClinicalTrials.gov (n=92), prespecified exclusion criteria with specific amounts of radiation exposure were provided in only 1% of studies; 37% of studies did not report any screening for prior radiation exposure. Using the screening protocol we developed for the SAGES study, 17% of 101 participants were deemed ineligible for the amyloid PET procedure because of prior exposure.

A systematic, standardized screening protocol to determine the prior radiation exposure of potential participants should be used as a tool in clinical studies involving elective radiologic procedures to minimize risk to participants.