Real-World Accuracy of a Continuous Glucose Monitoring System after Radiologic Exposure

Area of Science:

• Endocrinology
• Medical Imaging
• Biomedical Engineering

Background:

• Continuous glucose monitor (CGM) use is increasing, but manufacturer guidelines recommend removal during diagnostic imaging (X-ray, CT).
• This removal imposes financial, clinical, and psychosocial burdens, particularly for pediatric patients undergoing total pancreatectomy with islet autotransplantation (TPIAT).
• Interruptions in CGM use can hinder optimal diabetes management.

Purpose of the Study:

• To evaluate the impact of scatter radiation dose exposure on CGM accuracy.
• To assess if leaving CGMs in place during diagnostic imaging, outside the field of view, affects accuracy.
• To determine if this practice mitigates interruptions and burdens for TPIAT patients.

Main Methods:

• 14 pediatric TPIAT patients using insulin pumps and CGMs were monitored for 3 months post-surgery.
• CGMs were unshielded during routine X-ray or CT procedures.
• Absolute differences between CGM and glucometer values were analyzed using mixed models; Clarke error grid analyses (EGA) were performed.
• Scatter dose exposure was calculated retrospectively using anthropomorphic phantoms.

Main Results:

• Patients received a median of five imaging procedures with a median cumulative scatter dose of 559 µGy.
• No significant association was found between scatter dose exposure and the absolute difference between CGM and glucometer values (p=0.17).
• Over 98% of glucose values fell within clinically acceptable zones (A and B) on EGA, irrespective of scatter dose or time from TPIAT.

Conclusions:

• Scatter dose exposure from diagnostic imaging does not clinically impact CGM accuracy.
• Leaving CGM components in place when outside the field of view during imaging is safe and effective.
• This practice reduces interruptions, burdens, and costs for patients, improving diabetes management.