Does Imaging α_vβ₃ Integrin Expression with PET Detect Changes in Angiogenesis During Bevacizumab Therapy?

Approaches to Improve the Pharmacokinetics of Radiolabeled Glucagon-Like Peptide-1 Receptor Ligands Using Antagonistic Tracers

“…Mass spectrometry analysis was performed on an Ultraflex TOFTOF I instrument (Bruker Daltonik GmbH). Radiolabeling with 68 Ga was conducted using a 68 Ge/ 68 Ga generator IGG100 (Eckert and Ziegler) and Modular-Lab PharmTracer module (Eckert and Ziegler) essentially as described previously (28).…”

αvß3-Integrin–Targeted Magnetic Resonance Imaging for the Assessment of Early Antiangiogenic Therapy Effects in Orthotopic Breast Cancer Xenografts

“…[6][7][8] Bevacizumab-mediated VEGF inhibition was shown to significantly reduce endothelial α v ß 3 -integrin expression in solid tumors, hence underlining the potential of α v ß 3 -integrin as possible imaging biomarker of antiangiogenic therapy effects. 9 However, α v ß 3 -integrin-targeted in vivo imaging of tumor xenografts may be limited in the distinction between signal derived from endothelium-bound and signal derived from cell-bound imaging probes, as α v ß 3 -integrin is overexpressed on tumor vessel endothelium as well as on tumor cells. 2 MDA-MB-231 human breast cancer xenografts only have a very low cellular α v ß 3 -integrin expression and may therefore be a favorable tumor model for the in vivo imaging of α v ß 3 -integrinexpressing tumor microvasculature.…”

“…In addition, a 1-week VEGF inhibition proved to reduce α v ß 3 -integrin expression in squamous cell carcinoma xenografts. 9 It is furthermore known that α v ß 3 -integrin expression in breast cancer is activated via the VEGF pathway. 5 Accordingly, we found a significant suppression of α v ß 3 -integrin in the bevacizumabtreated group as compared with the control group.…”

PET/Computed Tomography Using New Radiopharmaceuticals in Targeted Therapy

“…88 However, successful antiangiogenic therapy with bevacizumab did not show any appreciable change in 68 Ga-NODAGAc(RGDfK) uptake on PET. 89 Other tracers evaluated for this purpose include 18 F-galacto-RGD, 18 Falfatide, 68 Ga-2,2',2"-(1,4,7-triazonane-1,4,7-triyl) triacetic acid-arginine-glycine-aspartic acid ( 68 Ga-NOTA-RGD), 68 Ga-triazacyclononanephosphinate-(arginine-glycine-aspartic acid) 3 [ 68 Ga-TRAP-(RGD) 3 ], and 64 Cu-1,4,7-triazacyclononane,1-glutaric acid-4,7-acetic acid-cyclo(ArgGly-Asp-d-Phe-Lys) [ 64 Cu-NODAGA-c(RGDfK)]. 90 Further research in this field is warranted.…”

“…62 Radiolabeled antibodies have slow kinetics and target binding, which necessitates delayed PET imaging. Hence, such tracers are labeled with PET radionuclides with long halflives, such as 64 Cu, 89 72 showed the utility of 89 Zr-cetuximab-PET imaging for EGFR mapping in metastatic colon cancer. Given the large size of monoclonal antibodies, various researchers have also evaluated antibody fragments and affibodies.…”