From the Department of Otorhinolaryngology & Head and Neck Surgery.
Therapeutic Nuclear Medicine, Department of Nuclear Medicine.
Clin Nucl Med. 2020 Mar;45(3):195-199. doi: 10.1097/RLU.0000000000002928.
Prostate-specific membrane antigen (PSMA) is highly expressed in prostate cancer cells and is exploited for imaging and treatment of patients with prostate cancer. Prostate-specific membrane antigen expression is also demonstrated in the tumor-associated neovasculature endothelium. Juvenile nasal angiofibroma (JNA), being a similar highly vascular tumor, may also demonstrate significant PSMA expression, which may be utilized for its imaging and treatment.
In this prospective study, 25 clinicoradiologically diagnosed primary JNA patients underwent PSMA PET/CT scan. The scan was performed after 45 to 60 minutes of intravenous injection of 2 to 3 mCi (74-111 MBq) of Ga-PSMA-HBED-CC on a dedicated PET/CT scanner. Low-dose CT scan was acquired from vertex to sternoclavicular joint (100 mA, 20 kVp, 3-mm slice thickness, 0.8 pitch). Images were reconstructed with iterative reconstruction technique (4 iterations, 24 subsets). The objective was to assess the intensity and pattern of PSMA uptake in primary JNA patients.
All cases (n = 25) of primary JNA showed PSMA expression in the tumor (100%). The median PSMA SUVmax ratio of tumor to background was 4.57 (range, 2.08-7.27). Intracranial extension in 14 of 25 patients was prominently visualized because of absence of background uptake in the brain. Advanced stage tumors demonstrated greater uptake than early tumors (P = 0.011). A statistically nonsignificant trend was noted for decreasing uptake with increasing age after normalizing for stage (Spearman correlation coefficient r = -0.08).
Assessment of PSMA expression in JNA by PSMA PET/CT opens up a new window of opportunity with respect to its radiological staging, vascularity assessment, and molecular characterization. A potential role in identification of the difficult residual-recurrent disease is anticipated and perhaps also in radioligand therapy for residual/recurrent JNA.Clinical Trials Registry of India (CTRI/2018/08/015479).
前列腺特异性膜抗原（PSMA）在前列腺癌细胞中高度表达，可用于前列腺癌患者的成像和治疗。PSMA 表达也在肿瘤相关新生血管内皮细胞中表现出来。青少年鼻血管纤维瘤（JNA）是一种类似的高血管肿瘤，也可能表现出明显的 PSMA 表达，这可能用于其成像和治疗。
在这项前瞻性研究中，25 例临床和放射学诊断为原发性 JNA 的患者接受了 PSMA PET/CT 扫描。在静脉注射 2 至 3mCi（74-111MBq）Ga-PSMA-HBED-CC 后 45 至 60 分钟，在专用的 PET/CT 扫描仪上进行扫描。低剂量 CT 扫描从头顶到胸锁关节（100mA、20kVp、3mm 层厚、0.8 螺距）进行。图像采用迭代重建技术（4 次迭代，24 个子集）重建。目的是评估原发性 JNA 患者 PSMA 摄取的强度和模式。
所有 25 例原发性 JNA 病例（n=25）的肿瘤均显示 PSMA 表达（100%）。肿瘤与背景的 PSMA SUVmax 比值中位数为 4.57（范围，2.08-7.27）。14 例 25 例颅内延伸的患者，由于大脑无背景摄取而明显显示。晚期肿瘤的摄取量大于早期肿瘤（P=0.011）。在按阶段进行标准化后，年龄与摄取量之间存在统计学上无意义的下降趋势（Spearman 相关系数 r=-0.08）。
PSMA PET/CT 评估 JNA 中的 PSMA 表达为其放射学分期、血管评估和分子特征开辟了一个新的机会。预计在识别困难的残留/复发性疾病方面将发挥潜在作用，也许在残留/复发性 JNA 的放射性配体治疗中也将发挥作用。印度临床试验注册中心（CTRI/2018/08/015479）。
