Role of 68 Ga-FAPI PET/CT in Assessing Hepatobiliary Malignancies : A Prospective Pilot Study

Area of Science:

• Nuclear Medicine
• Oncology
• Diagnostic Imaging

Background:

• Fibroblast activating protein inhibitor (FAPI) shows promise in imaging hepatobiliary malignancies.
• Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are primary liver cancers with significant diagnostic challenges.

Purpose of the Study:

• To evaluate the diagnostic performance of 68Ga-FAPI PET/CT in primary HCC and CC.
• To compare 68Ga-FAPI PET/CT with 18F-FDG PET/CT for diagnosing these malignancies.

Main Methods:

• Prospective recruitment of patients with suspected HCC or CC.
• Concurrent 18F-FDG PET/CT and 68Ga-FAPI PET/CT imaging within one week.
• Diagnosis confirmed by histopathology, cytology, and conventional radiology.

Main Results:

• 68Ga-FAPI PET/CT demonstrated high overall diagnostic accuracy (95.12%) compared to 18F-FDG PET/CT (63.41%) for primary hepatobiliary malignancies.
• FAPI PET/CT significantly outperformed FDG PET/CT in diagnosing CC (accuracy 95.24% vs. 57.14%).
• FAPI PET/CT showed higher lesion detection in primary HCC but questionable performance in metastatic HCC.

Conclusions:

• 68Ga-FAPI PET/CT is a highly effective tool for diagnosing cholangiocarcinoma.
• FAPI PET/CT shows potential for evaluating primary liver cancers, especially mucinous adenocarcinomas.
• Further research is needed to clarify the role of FAPI PET/CT in metastatic settings of HCC.