First-in-human imaging using [11C]MDTC: a radiotracer targeting the cannabinoid receptor type 2

Yong Du, Jennifer M. Coughlin, Mary Katherine Brosnan, Allen Chen, Laura K. Shinehouse, Rehab Abdallah, Martin A. Lodge, William B. Mathews, Chen Liu, Yunkou Wu, Il Minn, Paige Finley, Andrew W. Hall, Wojciech G. Lesniak, Robert F. Dannals, Andrew G. Horti, Martin G. Pomper

Research output: Contribution to journalArticlepeer-review


Purpose: We report findings from the first-in-human study of [11C]MDTC, a radiotracer developed to image the cannabinoid receptor type 2 (CB2R) with positron emission tomography (PET). Methods: Ten healthy adults were imaged according to a 90-min dynamic PET protocol after bolus intravenous injection of [11C]MDTC. Five participants also completed a second [11C]MDTC PET scan to assess test-retest reproducibility of receptor-binding outcomes. The kinetic behavior of [11C]MDTC in human brain was evaluated using tissue compartmental modeling. Four additional healthy adults completed whole-body [11C]MDTC PET/CT to calculate organ doses and the whole-body effective dose. Results: [11C]MDTC brain PET and [11C]MDTC whole-body PET/CT was well-tolerated. A murine study found evidence of brain-penetrant radiometabolites. The model of choice for fitting the time activity curves (TACs) across brain regions of interest was a three-tissue compartment model that includes a separate input function and compartment for the brain-penetrant metabolites. Regional distribution volume (VT) values were low, indicating low CB2R expression in the brain. Test-retest reliability of VT demonstrated a mean absolute variability of 9.91%. The measured effective dose of [11C]MDTC was 5.29 μSv/MBq. Conclusion: These data demonstrate the safety and pharmacokinetic behavior of [11C]MDTC with PET in healthy human brain. Future studies identifying radiometabolites of [11C]MDTC are recommended before applying [11C]MDTC PET to assess the high expression of the CB2R by activated microglia in human brain.

Original languageEnglish (US)
Pages (from-to)2386-2393
Number of pages8
JournalEuropean Journal of Nuclear Medicine and Molecular Imaging
Issue number8
StatePublished - Jul 2023


  • Cannabinoid receptor type 2
  • Dosimetry
  • Human
  • Pharmacokinetic
  • Positron emission tomography

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging


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