EJNMMI Research (May 2017)

First in-human radiation dosimetry of 68Ga-NODAGA-RGDyK

  • Silvano Gnesin,
  • Periklis Mitsakis,
  • Francesco Cicone,
  • Emmanuel Deshayes,
  • Vincent Dunet,
  • Augusto F. Gallino,
  • Marek Kosinski,
  • Sébastien Baechler,
  • Franz Buchegger,
  • David Viertl,
  • John O. Prior

DOI
https://doi.org/10.1186/s13550-017-0288-x
Journal volume & issue
Vol. 7, no. 1
pp. 1 – 10

Abstract

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Abstract Background Integrin-targeting radiopharmaceuticals have potential broad applications, spanning from cancer theranostics to cardiovascular diseases. We have previously reported preclinical dosimetry results of 68Ga-NODAGA-RGDyK in mice. This study presents the first human dosimetry of 68Ga-NODAGA-RGDyK in the five consecutive patients included in a clinical imaging protocol of carotid atherosclerotic plaques. Five male patients underwent whole-body time-of-flight (TOF) PET/CT scans 10, 60 and 120 min after tracer injection (200 MBq). Quantification of 68Ga activity concentration was first validated by a phantom study. To be used as input in OLINDA/EXM, time-activity curves were derived from manually drawn regions of interest over the following organs: brain, thyroid, lungs, heart, liver, spleen, stomach, kidneys, red marrow, pancreas, small intestine, colon, urinary bladder and whole body. A separate dosimetric analysis was performed for the choroid plexuses. Female dosimetry was extrapolated from male data. Effective doses (EDs) were estimated according to both ICRP60 and ICRP103 assuming 30-min and 1-h voiding cycles. Results The body regions receiving the highest dose were urinary bladder, kidneys and choroid plexuses. For a 30-min voiding cycle, the EDs were 15.7 and 16.5 μSv/MBq according to ICRP60 and ICRP103, respectively. The extrapolation to female dosimetry resulted in organ absorbed doses 17% higher than those of male patients, on average. The 1-h voiding cycle extrapolation resulted in EDs of 19.3 and 19.8 μSv/MBq according to ICRP60 and ICRP103, respectively. A comparison is made with previous mouse dosimetry and with other human studies employing different RGD-based radiopharmaceuticals. Conclusions According to ICRP60/ICRP103 recommendations, an injection of 200 MBq 68Ga-NODAGA-RGDyK leads to an ED in man of 3.86/3.92 mSv. For future therapeutic applications, specific attention should be directed to delivered dose to kidneys and potentially also to the choroid plexuses. Trial registration Clinical trial.gov, NCT01608516

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