Purpose

Radiolabeled probes targeting prostate-specific membrane antigen (PSMA) have been used in prostate cancer. Moreover, PSMA is also overexpressed on neovessels in hepatocellular carcinoma (HCC). This study aimed to preliminarily evaluate the diagnostic effectiveness of [⁶⁸Ga]Ga-PSMA-617 PET/MRI for HCC.

Methods

Patients suspected of HCC were prospectively enrolled in this single-center study (NCT05006326, 2021-08-16) to perform [⁶⁸Ga]Ga-PSMA-617 PET/MRI, along with contrast enhanced CT (ceCT) or ceMRI. The main suspicious intrahepatic lesions were resected and pathologically verified. Visual evaluation of [⁶⁸Ga]Ga-PSMA-617 PET/MRI images was performed on all lesions. Maximum standard uptake value (SUVmax), mean standard uptake value (SUVmean), tumor-to-liver ratio (TLR), tumor-to-blood ratio (TBR), and tumor-to-parotid ratio (TPR) were measured or calculated. The diagnostic efficiency of different modalities was summarized. PSMA expression was evaluated by immunohistochemistry and the correlation of PSMA expression and [⁶⁸Ga]Ga-PSMA-617 uptake in HCC primary tumors was quantitatively analyzed.

Results

A total of 12 patients (ten men and two women; mean age 58.75 ± 12.08 years) were included. Ten patients were diagnosed with HCC, 2 with intrahepatic cholangiocarcinoma (ICC), and 4 with hemangioma. The SUVmax, TLR, TBR, and TPR of HCC primary tumors were higher than those of ICC and hemangioma. The diagnostic accuracy of [⁶⁸Ga]Ga-PSMA-617 PET/MRI for primary HCC was 82.4%. When combined with ceCT or ceMRI, the accuracy increased to 88.2%. A moderate correlation was observed between SUVmax and mean PSMA expression in HCC primary tumors (R = 0.788).

Conclusion

Utilizing a hybrid PET/MRI system to combine [⁶⁸Ga]Ga-PSMA-617 PET/MRI with ceMRI is a promising one-stop solution for the accurate diagnosis of HCC.

Trial Registration

NCT05006326. Registered August 16, 2021, https://clinicaltrials.gov/study/NCT05006326.

中文翻译：

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[68Ga]Ga-PSMA-617 PET/MRI 用于疑似肝细胞癌患者的影像学检查

 目的

靶向前列腺特异性膜抗原 （PSMA） 的放射性标记探针已用于前列腺癌。此外，PSMA 在肝细胞癌 （HCC） 的新血管上也过表达。本研究旨在初步评价 [⁶⁸Ga]Ga-PSMA-617 PET/MRI 对 HCC 的诊断效果。

 方法

疑似 HCC 的患者前瞻性纳入这项单中心研究 （NCT05006326,2021-08-16），以进行 [⁶⁸Ga]Ga-PSMA-617 PET/MRI，以及对比增强 CT （ceCT） 或 ceMRI。切除主要可疑的肝内病灶并进行病理验证。对所有病灶进行 [⁶⁸Ga]Ga-PSMA-617 PET/MRI 图像的视觉评估。测量或计算最大标准摄取值 （SUVmax） 、平均标准摄取值 （SUVmean） 、肿瘤与肝脏比值 （TLR） 、肿瘤与血液比值 （TBR） 和肿瘤与腮腺比值 （TPR）。总结了不同模式的诊断效果。通过免疫组化评估 PSMA 表达，定量分析 HCC 原发肿瘤中 PSMA 表达与 [⁶⁸Ga]Ga-PSMA-617 摄取的相关性。

 结果

共纳入 12 例患者 （10 名男性和 2 名女性;平均年龄 58.75 ± 12.08 岁）。10 例患者诊断为 HCC，2 例肝内胆管癌 （ICC），4 例血管瘤。HCC 原发肿瘤的 SUVmax 、 TLR 、 TBR 和 TPR 高于 ICC 和血管瘤。[⁶⁸Ga]Ga-PSMA-617 PET/MRI 对原发性 HCC 的诊断准确率为 82.4%。当与 ceCT 或 ceMRI 联合时，准确率提高到 88.2%。在 HCC 原发肿瘤中观察到 SUVmax 和平均 PSMA 表达之间有中等相关性 （R = 0.788）。

 结论

利用混合 PET/MRI 系统将 [⁶⁸Ga]Ga-PSMA-617 PET/MRI 与 ceMRI 相结合，是准确诊断 HCC 的有前途的一站式解决方案。

 试用注册

NCT05006326。2021 年 8 月 16 日注册，https://clinicaltrials.gov/study/NCT05006326。