18 F-FDG and 68 Ga-FAPI-04 PET/CT Imaging in a Patient With Hepatocellular Carcinoma After 90 Y-SIRT

Area of Science:

• Nuclear Medicine
• Oncology
• Radiology

Background:

• Hepatocellular carcinoma (HCC) is a primary liver cancer.
• Yttrium-90 selective internal radiation therapy (90Y-SIRT) is a treatment for HCC.
• Monitoring treatment response is crucial for HCC management.

Purpose of the Study:

• To compare 18F-FDG PET/CT and 68Ga-FAPI-04 PET/CT for monitoring HCC after 90Y-SIRT.
• To evaluate the utility of each radiotracer in assessing treatment efficacy and tumor viability.

Main Methods:

• A single patient with HCC underwent 18F-FDG PET/CT and 68Ga-FAPI-04 PET/CT three weeks post-90Y-SIRT.
• Findings were correlated with 90Y SPECT/CT to assess radiotracer distribution.

Main Results:

• 18F-FDG PET/CT showed mild-to-moderate uptake in viable HCC and tumor thrombus.
• 68Ga-FAPI-04 PET/CT demonstrated high uptake in peritumoral tissues, aligning with 90Y distribution.
• 18F-FDG PET/CT identified viable tumor, while 68Ga-FAPI-04 PET/CT delineated the SIRT area.

Conclusions:

• 18F-FDG PET/CT is superior for early detection of viable HCC during 90Y-SIRT monitoring.
• 68Ga-FAPI-04 PET/CT indirectly visualizes the 90Y-SIRT treatment field.
• Combined or sequential imaging may offer comprehensive assessment of HCC treatment response.