GLP-1 agonists pose emerging challenge for PET-CT imaging, study finds

Researchers from Alliance Medical Ltd. performed a retrospective case series review of oncologic FDG PET-CT scans in patients taking GLP-1 agonists. They observed several atypical patterns of tracer uptake that could be misinterpreted as pathology if a patient’s medication history is not considered.

“We noticed unusual uptake in one of our patients on a GLP-1 agonist, which prompted a wider review across our network,” explained lead author Dr Peter Strouhal, Medical Director at Alliance Medical Ltd. “We found that these altered patterns are increasingly common, yet there is currently no national or international guidance in the UK addressing this emerging issue.”

Misinterpreting these uptake patterns can lead to unnecessary investigations, inappropriate cancer staging and delays in treatment, which may cause stress and uncertainty for patients. “Recognising the characteristic uptake associated with GLP-1 agonists helps avoid unnecessary anxiety and interventions, ensuring patients receive the right care, at the right time, without detours or doubt,” Dr Strouhal added.

At present, the researchers do not recommend altering patient preparation or stopping GLP-1 agonists prior to FDG PET-CT scans. Instead, they advise that imaging teams carefully document patients’ medication histories to inform interpretation while formal guidance is developed. Current UK guidelines do not address this issue, although Australian guidance suggests continuing treatment, fasting from midnight, scheduling morning scans and ensuring good glucose control.5

The research group intends to extend their data collection across additional imaging centres to provide a stronger evidence base for future national guidance. They also aim to establish international collaborations so that patients everywhere benefit from consistent and reliable PET-CT interpretation.

Reference:

GLP-1 agonists pose emerging challenge for PET-CT imaging, study finds, Beyond, Meeting: 38th Annual Congress of the European Association of Nuclear Medicine (EANM'25).