111In-cetuximab-F(ab')2 SPECT imaging for quantification of accessible epidermal growth factor receptors (EGFR) in HNSCC xenografts.

摘要: Abstract Background and purpose Immunohistochemical epidermal growth factor receptor (EGFR) expression does not correlate with treatment response in head neck squamous cell carcinomas (HNSCC). Aim was to apply the tracer 111 In-cetuximab-F(ab') 2 for EGFR microSPECT imaging investigate if uptake correlated EGFR-inhibition by cetuximab HNSCC xenografts. Usage of F(ab) fragments allows shorter interval between injection imaging. Materials methods Mice xenografts, SCCNij202, 153, 185 167 were imaged using . Subsequently, tumors analyzed autoradiography immunohistochemistry concentration determined. Tumor previously assessed treatment. Results MicroSPECT showed preferential Tumor-to-liver ratios 3.1±0.2 (SCCNij202), 2.8±0.4 (SCCNij153), 2.0±0.8 (SCCNij185), 2.0±0.4 (SCCNij167). fractions (fEGFR) differed significantly xenografts; 0.77±0.07 0.66±0.11 0.57±0.19 0.16±0.10 (SCCNij167) ( p tumor r =0.6, =0.7, proportionally associated three out four xenograft models. Conclusion good tumor-to-background contrast on imaging, allowing noninvasive assessment vivo , possibly evaluation EGFR-inhibition.