TY - JOUR T1 - <strong>In vivo assessment of CXCR4 receptor expression in High-grade Glioma using [68 Ga] Ga-Pentixafor PET/CT</strong> JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 3112 LP - 3112 VL - 63 IS - supplement 2 AU - Hessamoddin Roustaei AU - Habibeh Vosoughi AU - Nasim Norouzbeigi AU - Kazem Anvari AU - Susan Shafiei AU - Kamran Aryana Y1 - 2022/06/01 UR - http://jnm.snmjournals.org/content/63/supplement_2/3112.abstract N2 - 3112 Introduction: The tumor microenvironment determines various impacts on cancer biology. C-X-C chemokine receptor type 4 (CXCR4) signaling pathway has a crucial role between cancer cells and stroma. CXCR4 is a&amp;nbsp;G protein-coupled receptor generally localized on the cell surface. It is vital for cellular trafficking and tissue homeostasis. Although Low or absent levels of CXCR4 expression are observed in much healthy tissue, CXCR4 upregulation is identified in many malignancies. Invivo investigation by [68 Ga] Ga-labeled CXCR4 as a novel&amp;nbsp;probe using PET/CT has been investigated for tracing various kinds of solid and hematopoietic malignancies. As the most prevalent primary brain malignancy, high-grade gliomas are classified as WHO grade III and IV and have an unfavorable response-to-treatment and outcome. High-grade Glioma shows higher CXCR4 expression in in-vitro evaluation. This study aims to visually and semi-quantitatively invivo assessment of CXCR4 expression using 68Ga-Pentixafor (Pars-CixaforTM)&amp;nbsp;PET/CT and a possible relationship between CXCR4&amp;nbsp;density (uptake) and tumor grade.Methods: In this ongoing preliminary study, we investigated&amp;nbsp;a cohort trial of 22 treatment-na&amp;iuml;ve (neither radiotherapy nor chemotherapy) patients presented with high-grade anaplastic glioma using [68 Ga] Ga-CXCR4 (Pars-CixaforTM)&amp;nbsp;molecular imaging modality. The patients were&amp;nbsp;either resected or stereotactic biopsy-proven. All procedures in human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Written Informed consent was obtained from our patients.&amp;nbsp;Imaging was performed on a 6-slice dedicated PET/CT scanner 60 minutes post-injection of the tracer. Radio-labeling was done under GMP regulations via a fully-automated labeling module with 68Ga eluted from PARS-GalluGEN 68Ge/68Ga generator. Diagnostic CT(120 Kv, 240mAs, slice thickness 3 mm,512&amp;times;512 matrix size, increment of 30 mm/s, rotation time of 0.5s, and pitch index of 0.55) was made with no contrast, followed by one-FOV PET imaging.&amp;nbsp;Demographic data, histological tumor grade, the injected activity, the time interval between administration and acquisition were recorded.&amp;nbsp;Two board-certified nuclear medicine physicians reviewed the images independently and blinded.3D-VOIs were drawn around the lesion, blood pool (same-level sagittal venous sinus), contralateral brain healthy tissue, and SUVmax was generated for all VOIs. Standard MRI images were available for all patients and served as a reference standard.p-value &lt; 0.05 was considered to indicate statistical significance.Results: All patients showed uptake within tumoral lesions. Half of the patients were female (11/22). The mean age of the patients was 54.59 years. The result depicted that 18.18% (4/22) had WHO grade III. Three out of twenty-two participants had Stereotactic biopsy. The findings illustrated that the patients were referred and examined within 14-32 days (mean 21.71) after the biopsy. The mean of injected activity was 150.775±20.72 MBq (4.075±0.56 mCi) of 68Ga-Pentixafor. Mean SUVmax of the grade IV lesions was significantly higher than grade III (3.89±2.03 vs. 1.45±0.55, p=0.0293), respectively. The mean SUVmax of the blood pool activity and contralateral were reported 1.91± 0.70 and 0.13, respectively. While the target-to-blood pool ratio of the grade IV patients was 2.03, all the grade III showed lower lesion uptake than blood pool activity. both grade IV and III gliomas indicated a meaningful tumor-to-contralateral ratio (29.92 &amp;amp;11.15), respectively.Conclusions: Our preliminary analysis implies novel&amp;nbsp;68Ga-Pentixafor has well visual and semi-quantitative&amp;nbsp;characteristics. The present result highlights the possible implication for non-invasive in vivo differentiation within high-grade glioma (grade III vs. IV). It would emphasize other applications, e.g., theragnostic purposes and radiotherapy planning regarding precise tumor delineation ER -