RT Journal Article SR Electronic T1 Evaluation of CXCR4 expression of pancreatic cancer with 68Ga-Pentixafor PET/MRI - initial experience JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 496 OP 496 VO 58 IS supplement 1 A1 Leisser, Asha A1 Nejabat, Marzieh A1 Ba-Ssalamah, Ahmed A1 Schindl, Martin A1 Prager, Gerald A1 Wadsak, Wolfgang A1 Mitterhauser, Markus A1 Pfaff, Sarah A1 Kropf, S A1 Wester, Hans A1 Hacker, Marcus A1 Hartenbach, Markus A1 Haug, Alexander YR 2017 UL http://jnm.snmjournals.org/content/58/supplement_1/496.abstract AB 496Objectives: Previous histopathological studies report that a high expression of CXCR4 is prognostic for growth, invasion, development of metastases, and survival in pancreatic cancer, thus leading to significantly worse outcome. Furthermore an overexpression of CXCR4 was associated with resistance to the chemotherapeutic drug Gemcitabine.Methods: This study was approved by the local ethical committee. We prospectively included 10 of intended 92 patients with histologically verified pancreatic cancer in this pilot study (6 male, mean age 68). Precursor for 68Ga-Pentixafor synthesis was provided by Scintomics in GMP grade. 60 minutes after application of mean 172 MBq 68Ga-Pentixafor whole-body PET images were acquired with 5 minutes per bed position. Simultaneously the following MRI sequences were acquired: axial T1 vibe Dixon, coronal T2 haste, axial diffusion weighted images (ADC, b_50, b_800), DCE. We evaluated the uptake (SUVmax, SUVmean, SUVpeak), volume of the primary tumor and the SUVmax of the metastases. Background activity was measured in the liver. Treatment response and disease progress were determined in standard of care follow-up. Correlations were evaluated using Pearson’s correlation coefficient (PCC).Results: In 7/10 patients uptake of 68Ga-Pentixafor was higher than the median and thus graded as a strong CXCR4 expression. Mean SUVmax was 5.5 (range 4.1-9.3), SUVmean 3.4 (range 2.9-5.3), and SUVpeak 4.2 (range 3.3-6.8). The mean SUVmax of the liver was 1.2. The tumor-to-background ratio was satisfactorily with mean SUVmax of 2.4 (range 1.8-3.1). The mean tumor volume was 29.9 ml (range 11.7-76.1). Median follow-up was 11 months. All patients received chemotherapy (3 FOLFIRINOX, 1 FOLFOX, 3 Gemcitabine, 1 Cisplatin/Gemcitabine). In the correlation analysis only tumor volume correlated significantly with SUVmax (PCC=0.7) and SUVmean (PCC=0.7) at level 0.05. No significant correlations between uptake, treatment, and response and disease stage were found in this preliminary analysis.Conclusion: In the present study 7/10 tumors showed strong CXCR4 expression as assessed with 68Ga-Pentixafor. The correlation with treatment response and survival has yet to be analysed in a larger patient population. Research Support: Scintomics GmbH