Clinical Application of 68Ga-PSMA PET/MR for Diagnosis and Staging in Hepatocellular Carcinoma

A Prospective Study of Clinical Application of 68Ga-PSMA PET/MR for Diagnosis and Staging in Hepatocellular Carcinoma

In this prospective study, 68Ga-PSMA integrated PET/MR imaging was applied for the diagnosis and staging of hepatocellular carcinoma (HCC). The detection and diagnostic performance of 68Ga-PSMA PET/MR for HCC was evaluated in comparison with the gold standard of puncture biopsy or postoperative pathology. The aim is to make up for the deficiency in FDG PET imaging in the diagnosis and staging of HCC.

Hepatocellular carcinoma (HCC) is one of the most dangerous malignancies in human health, with the sixth highest incidence of malignant tumors. However, early diagnosis of HCC is difficult. The currently used glucose metabolism imaging agent, 18F-FDG, also accumulates in large amounts in normal liver tissue, which affects the diagnosis of HCC lesions. Prostate specific membrane antigen (PSMA), a type II transmembrane glycoprotein encoded by the FOLH1 gene, is highly expressed in prostate epithelial cells and has been widely used in the study of prostate cancer. Further studies have found that it is involved in tumor angiogenesis in a variety of solid tumors of non-prostate tissue origin. It is also overexpressed in neovascular endothelial cells of hepatocellular carcinoma, which is significantly associated with tumor grading, staging and prognosis. Moreover, PSMA also has great potential as a target for anti-vascular therapy. The integrated PET/MR is currently the most advanced imaging device, combining the advantages of PET and MR, with the high sensitivity of PET and the high soft tissue contrast of MR. It has significant advantages over PET/CT in head and neck, abdominopelvic lesions. And MR imaging has no additional radiation and a higher biosafety profile. In view of the potential of 68Ga-PSMA for HCC imaging, this prospective study proposes to apply 68Ga-PSMA integrated PET/MR imaging for diagnosis and staging of HCC. The detection and diagnostic performance of 68Ga-PSMA PET/MR for HCC was evaluated in comparison with the gold standard of biopsy or postoperative pathology. The aim is to make up for the deficiency in FDG PET imaging in the diagnosis and staging of HCC.

The investigators selected patients with a high clinical suspicion of HCC, or patients with confirmed HCC without tumour-related treatment who were to be biopsied or surgically resected to obtain pathological results. Patients signed an informed consent form and underwent 68Ga-PSMA PET/MR imaging (or PET/CT imaging if the patient had a contraindication to MR imaging).

Intravenous access is established in advance, intravenous bolus injection, 68Ga-PSMA dose is about 1.85-3.7 MBq/kg body weight (0.05-0.1 mCi/kg). Patients were encouraged to drink water after injection and asked to empty their bladder before PET scan.

Sensitivity and specificity of 68Ga-PSMA PET/MR for diagnosis and staging in hepatocellular carcinoma.

For patients without any treatment, the initial diagnosis and staging results of 68Ga-PSMA PET/MR (PET/CT) will be compared with pathological, clinical and follow-up results.

PSMA-related immunohistochemical staining and quantification of PSMA expression was performed on biopsy/surgical tissue sections from patients. The investigators analysed the correlation between HCC 68Ga-PSMA uptake and PSMA expression levels in tissues.

Inclusion Criteria: Each subject must meet all the inclusion criteria to be eligible for the study. Subjects or their legal representatives are able to sign an informed consent form Subjects are committed to comply with the study procedures and cooperate with the implementation of the full study Subjects are 18 years of age or older, regardless of gender Subjects with high suspicion of HCC, or diagnosed HCC without tumour-related treatment (supporting evidence including serum AFP, MRI, CT and other imaging data and histopathology), and in good general condition Subjects intend to obtain pathological results by biopsy or surgical resection Exclusion Criteria: All patients meeting any of the exclusion criteria will be excluded from the study. Patients or their legal representatives are unable or unwilling to sign the informed consent form Patients are unable to cooperate in the conduct of the full study Patients with acute systemic illness and electrolyte disturbances Patients with other previous malignancies or a combination of other malignancies Patients who are pregnant or lactating women