Preliminary clinical assessment of the relationship between tumor alphavbeta3 integrin and perfusion in patients studied with [(18)F]fluciclatide kinetics and [(15)O]H(2)O PET

BACKGROUND: [(18)F]fluciclatide, a peptide ligand with high affinity for αvβ3/αvβ5 integrins, is a proposed biomarker of tumor angiogenesis. The study rationale was to perform a preliminary evaluation of the relationship between tumor [(18)F]fluciclatide uptake and perfusion by [(15)O]H(2)O PET. METHODS: Patients with non-small cell lung cancer and melanoma underwent dynamic imaging with arterial sampling following injection of [(15)O]H(2)O and [(18)F]fluciclatide. Quantification was performed using a one-tissue compartmental model for [(15)O]H(2)O and a two-tissue model for [(18)F]fluciclatide at volume-of-interest level, and SUV at voxel level. RESULTS: Tumor binding potential (k(3)/k(4) ratio) of [(18)F]fluciclatide tumor was 5.39 ± 1.46, consistent with previous studies in breast cancer metastases. Voxel-by-voxel maps of [(18)F]fluciclatide delivery strongly correlated with [(15)O]H(2)O-based perfusion (p < 10(−4) tumor, 1,794 ± 1,331 voxels). Interestingly, this correlation was lost when retention of [(18)F]fluciclatide at late time-points was compared with perfusion (p > 0.15). CONCLUSIONS: Our study suggests tumor [(18)F]fluciclatide retention is unrelated to tumor perfusion, supporting use of late (60-min) imaging protocols in patients. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13550-014-0030-x) contains supplementary material, which is available to authorized users.