TY - JOUR T1 - PET-Based Human Dosimetry of the Dimeric α<sub>v</sub>β<sub>3</sub> Integrin Ligand <sup>68</sup>Ga-DOTA-E-[c(RGDfK)]<sub>2</sub>, a Potential Tracer for Imaging Tumor Angiogenesis JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 404 LP - 409 DO - 10.2967/jnumed.115.161653 VL - 57 IS - 3 AU - Victoria López-Rodríguez AU - Carlos Galindo-Sarco AU - Francisco O. García-Pérez AU - Guillermina Ferro-Flores AU - Oscar Arrieta AU - Miguel A. Ávila-Rodríguez Y1 - 2016/03/01 UR - http://jnm.snmjournals.org/content/57/3/404.abstract N2 - Peptides containing the Arg-Gly-Asp (RGD) sequence have high affinity for αvβ3 integrin receptors overexpressed in tumor cells. The objective of this research was to determine the biodistribution and estimate the radiation dose from 68Ga-DOTA-E-[c(RGDfK)]2 using whole-body PET scans in humans. Methods: Five healthy volunteers (2 women, 3 men; mean age ± SD, 37.2 ± 15.6 y; range, 28–65 y; mean weight, 79.2 ± 21.0 kg; range, 64–115 kg) were included. After intravenous injection of the tracer (198.3 ± 3.3 MBq), 3 successive whole-body (vertex to mid thigh) PET/CT scans at 3 time points (30, 60, and 120 min) were obtained on a 16-slice PET/CT scanner. The subjects did not void the bladder until the entire series of images was completed. Low-dose CT without contrast agent was used for anatomic localization and attenuation correction. OLINDA/EXM software was applied to calculate human radiation doses using the reference adult model. Results: The highest uptake was in the urinary bladder, followed by the liver, kidneys, and spleen, in descending order. The critical organ was the urinary bladder wall. The mean effective doses (all subjects, men and women) were 34.1 ± 4.9, 31.0 ± 2.4, and 20.9 ± 5.2 μSv/MBq for the no-voiding, 2.5-h-voiding, and 1-h-voiding models, respectively. Conclusion: Of particular interest in this research was the visualization of the choroid plexus and ventricular system, which seems to be a characteristic of RGD–dimeric peptides. Measured absorbed doses and effective doses are comparable to other previously reported RGD-based radiopharmaceuticals labeled with 68Ga and 18F. Therefore, 68Ga-DOTA-E-[c(RGDfK)]2 can safely be used for imaging integrin αVβ3 expression. ER -