X-ray durability of continuous glucose monitoring sensors during pseudo-measurement

Purpose Although continuous glucose monitoring is a valuable tool for diabetes care, removal of its sensor is recommended for safety reasons when X-ray beams are applied. This study aimed to examine whether the sensor (FreeStyle Libre system) develops a tendency to fail due to X-ray beams when the glucose value is constantly read. Methods A method for uninterruptedly reading a glucose value by the sensor without adhering to the human body was developed as a pseudo-measurement by placing it in hydrogen peroxide. Malfunction in an electronic device caused by X-ray beams was assumed to be due to neutrons, dose rate, and accumulated dose. Six sensors were irradiated by X-ray beams at a dose rate of 18–300 cGy/min, with an accumulated dose of 0.18–35 Gy. Low-energy kV X-ray beams were employed to rule out the possibility of malfunction caused by neutrons. Results All sensors worked normally during and after the irradiations, indicating their safety in terms of accumulated dose. The glucose values were within the acceptance criterion during the irradiations, indicating the safety in terms of dose rate. Although disconnection of the system occurred in two sensors some days after the irradiation, the causes were considered to be a result of instability of the pseudo-measurement rather than radiation. Conclusion It was suggested that the Libre sensor can bear X-ray beams with kV energy in terms of dose rate and accumulated dose, and that patients can continue to wear and use their sensors while undergoing irradiation in usual clinical situations.