PT  - JOURNAL ARTICLE
AU  - Andreas K. Buck
AU  - Alexander Haug
AU  - Niklas Dreher
AU  - Alessandro Lambertini
AU  - Takahiro Higuchi
AU  - Constantin Lapa
AU  - Alexander Weich
AU  - Martin G. Pomper
AU  - Hans-Jürgen Wester
AU  - Anja Zehnder
AU  - Andreas Schirbel
AU  - Samuel Samnick
AU  - Marcus Hacker
AU  - Verena Pichler
AU  - Stefanie Hahner
AU  - Martin Fassnacht
AU  - Hermann Einsele
AU  - Sebastian Serfling
AU  - Rudolf A Werner
TI  - Imaging of C-X-C Motif Chemokine Receptor 4 Expression in 690 Patients with Solid or Hematologic Neoplasms using <sup>68</sup>Ga-PentixaFor PET
AID  - 10.2967/jnumed.121.263693
DP  - 2022 Mar 01
TA  - Journal of Nuclear Medicine
PG  - jnumed.121.263693
4099  - http://jnm.snmjournals.org/content/early/2022/03/03/jnumed.121.263693.short
4100  - http://jnm.snmjournals.org/content/early/2022/03/03/jnumed.121.263693.full
AB  - Background: In recent years, molecular imaging adressing the C-X-C motif chemokine receptor 4 (CXCR4) has increasingly been utilized in various clinical settings. Here, we aimed to assess radiopharmaceutical uptake and image contrast to determine the most relevant clinical applications for CXCR4-directed imaging. We also investigated the impact of specific activity on scan contrast. Methods: 690 patients with a variety of neoplasms underwent a total of 777 PET/CT scans with 68Ga-PentixaFor, serving as CXCR4-specific radioligand. A semiquantitative target lesion (TL) analysis was conducted [providing maximum standardized uptake values (SUVmax) and target-to-blood pool ratio (TBR), defined as SUVmax (from TL) divided by mean SUV (from blood pool)]. The applied specific activity (in MBq/µg) was compared to semi-quantitative assessments. Results: Of the 777 scans, 242 did not show discernible uptake in disease sites, leaving 535 PET scans (68.9%) for further analysis. Very high tracer uptake (SUVmax > 12) was found in multiple myeloma (MM; n = 113), followed by adrenocortical carcinoma (n = 30), mantle cell lymphoma (MCL; n = 20), adrenocortical adenoma (n = 6) and small cell lung cancer (SCLC; n = 12). Providing information on image contrast, comparable results for TBR were recorded, with TBR (>8) in MM, MCL and acute lymphoblastoid leukemia (n = 6). When comparing specific activity with semiquantitative parameters, no significant correlation was found for SUVmax or TBR (P ≥ 0.612). Conclusion: In this large cohort, 68Ga-PentixaFor demonstrated high image contrast in a variety of neoplasms, particularly for hematologic malignancies, SCLC and adrenocortical neoplasms. The present analysis may provide a roadmap to detect patients who may benefit from CXCR4-targeted therapies.