A case report of continuous glucose monitoring for a radiographer working in a 1.5T MR Linac

This case report details the first in-vivo use of continuous glucose monitoring (CGM) technology by a therapeutic radiographer working in magnetic resonance image (MRI) guided radiotherapy with type 1 diabetes (T1D) at our institution. As adoption rates of this device increase, understanding how they perform in MR environments is important for staff working in MR specific roles.

For a single member of an MRI guided radiotherapy team with type I diabetes, daily CGM readings in mmol/L were recorded for 4 months when working in all areas of an Elekta Unity MR Linac (Elekta AB, Sweden). These measurements were compared to the mean daily self-monitoring blood glucose (SMBG) readings taken at 2-hour intervals whilst in work over a 4-month testing period. A cloud-based diabetes management system demonstrated successful data transmission as 96% of BG readings had been received from the CGM across all areas of working. A Pearson correlation coefficient of CGM and SMBG readings showed a positive correlation (r = 0.70) and a paired T-Test indicated no significant differences (p = 0.63), indicating CGM reliability in this MR Linac environments across 122 days of testing.

This case highlights the feasibility and safety of using the Freestyle Libre 2 CGM (FreeStyle Libre 2, Abbott Diabetes Care) for an individual with T1D working in an MR Linac. The data presented here is specific to this scenario and serves as informative guidance for healthcare professionals. Further research and standardisation efforts are needed to enhance the compatibility of non-invasive CGMs in MRI environments.