Assessment of PET drug adverse events in the U.S. since the implementation of 21 CFR part 212

Multiple new Positron Emission Tomography (PET) radiopharmaceuticals (RPhs) have recently been approved by the U.S. Food and Drug Administration (FDA). Despite the generally accepted safety profile of PET RPhs supported by millions of doses administered per year, the microdoses used in most injections, and the low incidence of adverse events (AEs), there appear to be elevated concerns from regulatory authorities regarding the safety of PET RPhs in recent years. There have been prior reports on the prevalence of AEs from RPhs, but most of them are outdated and do not reflect the current state-of-the-art and best practices. To address the gap, this retrospective study assesses risks associated with PET RPhs by reviewing AEs reported to the FDA Adverse Events Reporting System (FAERS) since the implementation of the PET good manufacturing practice (GMP) regulations in 21 CFR 212 in 2012. Data for AEs reported for approved PET RPhs were collected from the FAERS database. Data were collected during December 2025 for AEs reported between 2012 and 2024. FDA approved PET RPhs were searched using all known names for each drug. For each RPh, the following tables were downloaded from the database: (a) case count by received year; (b) cases by reaction; and (c) listing of cases. Tables downloaded for each radiopharmaceutical were combined, and duplicated entries removed. AE reports were then categorized based on the manufacturing regulatory oversight and, for the purposes of this report, we focused on AEs reported for 10 PET RPhs manufactured under 21 CFR 212. Almost 24 million adverse event reports for all drug products were transmitted to FDA between 2012 and 2024. Of these, 932 (or 0.0039%) were AEs submitted to FAERS for FDA-approved PET RPhs manufactured in the US. Of these AEs, 451 were reported for PET RPhs manufactured under 21 CFR 212. This represents approximately 7.0 AEs per 10 5 RPh injections performed in 2024 for all PET RPhs or 4.3/10 5 for PET RPhs manufactured under the PET GMP regulations. At least one adverse reaction to the RPh was reported in 237 of the 451 cases recorded, and two-thirds of these (157, 66.2%) were characterized as non-serious. The FAERS data confirm that PET RPhs can be generally recognized as safe and effective. The extremely low numbers of AEs for PET RPhs manufactured according to 21 CFR 212 and the lack of correlation between manufacturing issues and safety AEs overall support a low risk profile for this class of drugs. Moreover, these data do not appear to justify significant changes to the existing regulations, or more stringent regulation of PET drug manufacture beyond those currently in place.