PT  - JOURNAL ARTICLE
AU  - Ken Herrmann
AU  - Constantin Lapa
AU  - Hans-Juergen Wester
AU  - Margret Schottelius
AU  - Christiaan Schiepers
AU  - Uta Eberlein
AU  - Christina Bluemel
AU  - Ulrich Keller
AU  - Stefan Knop
AU  - Saskia Kropf
AU  - Andreas Schirbel
AU  - Andreas K. Buck
AU  - Michael Lassmann
TI  - Biodistribution and Radiation Dosimetry for the Chemokine Receptor CXCR4-Targeting Probe <sup>68</sup>Ga-Pentixafor
AID  - 10.2967/jnumed.114.151647
DP  - 2015 Mar 01
TA  - Journal of Nuclear Medicine
PG  - 410--416
VI  - 56
IP  - 3
4099  - http://jnm.snmjournals.org/content/56/3/410.short
4100  - http://jnm.snmjournals.org/content/56/3/410.full
SO  - J Nucl Med2015 Mar 01; 56
AB  - 68Ga-pentixafor is a promising PET tracer for imaging the expression of the human chemokine receptor 4 (CXCR4) in vivo. The whole-body distribution and radiation dosimetry of 68Ga-pentixafor were evaluated. Methods: Five multiple-myeloma patients were injected intravenously with 90–158 MBq of 68Ga-pentixafor (mean ± SD, 134 ± 25 MBq), and a series of 3 rapid multiple-bed-position whole-body scans were acquired immediately afterward. Subsequently, 4 static whole-body scans followed at 30 min, 1 h, 2 h, and 4 h after administration of the radiopharmaceutical. Venous blood samples were obtained. Time-integrated activity coefficients were determined from multiexponential regression of organ region-of-interest data normalized to the administered activity, for example, the time-dependent percentages of the injected activity per organ. Mean organ-absorbed doses and effective doses were calculated using OLINDA/EXM. Results: The effective dose based on 150 MBq of 68Ga-pentixafor was 2.3 mSv. The highest organ-absorbed doses (for 150 MBq injected) were found in the urinary bladder wall (12.2 mGy), spleen (8.1 mGy), kidneys (5.3 mGy), and heart wall (4.0 mGy). Other organ mean absorbed doses were as follows: 2.7 mGy, liver; 2.1 mGy, red marrow; 1.7 mGy, testes; and 1.9 mGy, ovaries. Conclusion: 68Ga-pentixafor exhibits a favorable dosimetry, delivering absorbed doses to organs that are lower than those delivered by 18F-FDG– or 68Ga-labeled somatostatin receptor ligands.