In vivo assessment of safety, biodistribution, and radiation dosimetry of the [¹⁸F]Me4FDG PET-radiotracer in adults

Background: Approaches targeting the sodium-glucose cotransporter (SGLT) could represent a promising future therapeutic strategy for numerous oncological and metabolic diseases. In this study, we evaluated the safety, biodistribution and radiation dosimetry of the glucose analogue positron emission tomography (PET) agent [¹⁸F] labeled alpha-methyl-4-deoxy-4-[¹⁸F]fluoro-D-glucopyranoside ([¹⁸F]Me4FDG) with high sodium-glucose cotransporter and low glucose transporter (GLUT) affinity. For this purpose, five healthy volunteers (1 man, 4 women) underwent multiple whole-body PET/computed tomography (CT) examinations starting with injection and up to 4 h after injection of averaged (2.4 ± 0.1) MBq/kg (range: 2.3-2.5 MBq/kg) administered activity. The PET/CT scans were conducted in 5 separate sessions, blood pressure and temperature were measured, and blood and urine samples were collected before the scans and one hour after injection to assess toxicity. Measurements of [¹⁸F]Me4FDG radioactivity in organs of interest were determined from the PET/CT scans at 5 time points. Internal dosimetry was performed on voxel level using a fast Monte Carlo approach.

Results: All studied volunteers could well tolerate the [¹⁸F]Me4FDG and no adverse event was reported. The calculated effective dose was (0.013 ± 0.003) mSv/MBq. The organs with the highest absorbed dose were the kidneys with 0.05 mSv/MBq per kidney. The brain showed almost no uptake. After 60 min, (12 ± 15) % of the administered dose was excreted into the bladder.

Conclusion: Featuring an effective dose of only 0.013 ± 0.003 mSv/MBq and no occurrence of side effects, the glucose analogue [¹⁸F]Me4FDG seems to be a safe radio-tracer with a favorable biodistribution for PET imaging and also within several consecutive scans.

Trial registration number: NCT03557138, Registered 22 February 2017, https://ichgcp.net/clinical-trials-registry/NCT03557138 .