Communication is key: Nuclear medicine departments fail diabetes patients preparing for 18-FDG PET/CT

Nuclear medicine departments are not communicating proper pre-scan instructions to diabetes mellitus management patients for optimizing fluoride-18 fluorodeoxyglucose (FDG) PET/CT imaging, according to new research published in the Journal of the American College of Radiology.

“Our primary finding is that relevant diabetes-specific information is commonly withheld by nuclear medicine call centers throughout the United States when discussing oncologic FDG PET/CT, despite local and national policies indicating its importance,” wrote lead author Andrew Kaiser, MD, with the University of Michigan in Ann Arbor, and colleagues.

In this prospective observational study, Kaiser et al. called 65 nuclear medicine scheduling lines posing as a family member of a patient with diabetes and cancer who has little knowledge on the topic. The researchers used a pre-written script and called each center three times a day on three various days to schedule a FDG PET/CT scan.

The team made 195 phone calls which averaged 2.9 minutes. They collected blood glucose threshold for rescheduling an exam; when or if to stop medications; fasting requirement; and preferred time of day.

Kaiser and colleagues found diabetes-specific information was “often” withheld, and physicians were never involved in explaining the usual method for communicating FDG PET/CT exam details.

More than 90 percent of the time, no preferred exam time was recommended, despite 2016 American College of Radiology (ACR) practice paramaters suggesting imaging should be scheduled early in the morning, if possible. Additional results were as follows:

Glucose threshold: This was specified in 29 percent of contacts, and the mean stated maximum level was 195 mg/ dL. ACR recommendations state if that level is above 200 mg/dL the exam should be rescheduled.

“Patients with diabetes mellitus who arrive unaware of this policy may lose money, time off work, and personal time only to have their examination be rescheduled; therefore, effective communication of this need is important,” the authors wrote.

Fasting: Sixty-three percent recommended a fasting duration, with 10 percent suggesting to do so after midnight—in-line with ACR recommendations.

Medication instruction: Information was withheld in 88 percent of calls for metformin, 30 percent for short-acting insulin and 99 percent for long-acting insulin. The ACR recommends withholding all insulin and oral diabetic medication after midnight. With regard to holding metoformin, instructions varied widely by center with one percent specifically stating not to hold metformin and 10 percent suggesting holding short-acting insulin after midnight.

“Our results show that the national guidelines are heterogeneously followed and, more importantly, are rarely completely explained,” the authors wrote. “If patients are unaware of these policies, they are much less likely to be in compliance at the time of scanning.”

They concluded by calling for advocacy on a national level to implement exam preparation instructions and reduce harm to diabetes patients.