A phase one, single-dose, open-label, clinical safety and PET/MR imaging study of 68Ga-DOTATOC in healthy volunteers.

This prospective pilot study provides a dynamic whole body PET/MR image database, clinical safety, biodistribution profile and dosimetry of 68Ga-DOTATOC in healthy subjects, to establish a baseline and standard reference for its use in diagnosis and treatment response evaluation among patients with somatostatin receptor expressing neoplastic diseases. Dynamic whole body PET/MR imaging was performed in 12 healthy subjects (male/female: 8/4) after injection of 242.39 ± 53.38 MBq (mean ± SD) 68Ga-DOTATOC. Images were acquired 15, 60, 120, and 240 minutes post injection. Subjects were assessed at baseline and after 68Ga-DOTATOC PET/MR by monitoring vital signs, 12-lead electrocardiograms, complete blood count, comprehensive metabolic panel, and urinalysis. Adverse events were monitored for one week after injection. Organ dosimetry was estimated using OLINDA/EXM 1.1 software. Radiotracer was exclusively eliminated via urinary tract (18.8 ± 1.0% of injected dose within 4 hours) and no redistribution was observed. Bladder wall, spleen and kidneys received the highest radiation exposure (0.64 ± 0.1 mSv/MBq, 0.29 ± 0.14 mSv/MBq, and 0.1 ± 0.02 mSv/MBq, respectively). Mean effective dose yielded 0.048 ± 0.007 mSv/MBq. No adverse events were reported during the one-week follow-up period. Follow-up laboratory tests and electrocardiograms showed no changes compared to the baseline. The use of MRI provided valuable anatomical information and eliminated the risk of radiation exposure compared to CT.