From the Departments of Nuclear Medicine.
Radiodiagnosis and Imaging.
Clin Nucl Med. 2024 Apr 1;49(4):e141-e148. doi: 10.1097/RLU.0000000000005073. Epub 2024 Feb 1.
The aim of this study was to evaluate the diagnostic potential of 68 Ga-pentixafor PET/CT for in vivo CXCR4 receptors imaging in glioma and its possible role in response assessment to radiochemotherapy (R-CT).
Nineteen (12 men, 7 women) patients with glioblastoma multiforme (GBM) underwent 68 Ga-pentixafor PET/CT, contrast-enhanced MR, and MR spectroscopy. Patients were divided in to 2 groups, that is, group I was the presurgical (n = 9) group in which the scanning was done before surgery, and PET findings were correlated with CXCR4 receptors' density. The group II was the postsurgical (n = 10) group in which the scanning was done before and after R-CT and used for treatment response evaluation. The quantitative analysis of 68 Ga-pentixafor PET/CT evaluated the mean SUV max , SUV mean , SUV peak , and T/B values. MR spectroscopy data evaluated the ratios of tumor metabolites (choline, NAA, creatine).
68 Ga-Pentixafor uptake was noted in all (n = 19) the patients. In the group I, the mean SUV max , SUV mean , SUV peak , and T/B values were found to be 4.5 ± 1.6, 0.60 ± 0.26, 1.95 ± 0.8, and 6.9 ± 4.6, respectively. A significant correlation ( P < 0.005) was found between SUV mean and choline/NAA ratio. Immunohistochemistry performed in 7/9 showed CXCR4 receptors' positivity (intensity 3 + ; stained cells >50.0%). In the group II, the mean SUV max at baseline was 4.6 ± 2.1 and did not differ (4.4 ± 1.6) significantly from the value noted at post-R-CT follow-up PET/CT imaging. At 6 months' clinical follow-up, 4 patients showed stable disease. SUV max and T/B ratios at follow-up imaging were lower (3.70 ± 0.90, 2.64 ± 1.35) than the corresponding values (4.40 ± 2.8; 2.91 ± 0.93) noted at baseline. Six (6/10) patients showed disease progression, and the mean SUV max , and T/B ratio in these patients were significantly ( P < 0.05) higher than the corresponding values at baseline and also higher than that noted in the stable patients.
68 Ga-Pentixafor PET/CT can be used for in vivo mapping of CXCR4 receptors in GBM. The technique after validation in a large cohort of patients may have added diagnostic value for the early detection of GBM recurrence and for treatment response evaluation.
本研究旨在评估 68Ga- pentixafor PET/CT 对体内 CXCR4 受体成像的诊断潜力及其在放化疗反应评估中的可能作用。
19 名（男 12 名，女 7 名）多形性胶质母细胞瘤（GBM）患者接受了 68Ga- pentixafor PET/CT、对比增强磁共振和磁共振波谱检查。患者分为两组，即 I 组为术前组（n=9），在手术前进行扫描，PET 发现与 CXCR4 受体密度相关。II 组为术后组（n=10），在放化疗前和后进行扫描，用于治疗反应评估。68Ga- pentixafor PET/CT 的定量分析评估了最大 SUVmax、平均 SUVmean、SUVpeak 和 T/B 值。磁共振波谱数据评估了肿瘤代谢物（胆碱、NAA、肌酸）的比值。
所有（n=19）患者均有 68Ga- pentixafor 摄取。在 I 组中，最大 SUVmax、平均 SUVmean、SUVpeak 和 T/B 值分别为 4.5±1.6、0.60±0.26、1.95±0.8 和 6.9±4.6。SUVmean 与胆碱/NAA 比值之间存在显著相关性（P<0.005）。在 7/9 例中进行了免疫组织化学检查，显示 CXCR4 受体阳性（强度 3+；染色细胞>50.0%）。在 II 组中，基线时最大 SUVmax 为 4.6±2.1，与放化疗后随访 PET/CT 成像时的（4.4±1.6）值无显著差异。在 6 个月的临床随访中，4 例患者病情稳定。随访时的 SUVmax 和 T/B 比值（3.70±0.90、2.64±1.35）低于基线时的相应值（4.40±2.8；2.91±0.93）。6（6/10）例患者病情进展，这些患者的最大 SUVmax 和 T/B 比值明显（P<0.05）高于基线值，也高于稳定患者的值。
68Ga- pentixafor PET/CT 可用于 GBM 中 CXCR4 受体的体内定位。该技术在更大的患者队列中验证后，可能对早期发现 GBM 复发和治疗反应评估具有额外的诊断价值。
