⁶⁸Ga-PSMA PET/CT Versus ¹⁸F-FDG PET/CT for Imaging of Hepatocellular Carcinoma

Abstract

Objectives: This study aimed to compare the metabolic parameters obtained from 18 fluorine-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) and gallium-68 ( 68 Ga)-prostate-specific membrane antigen (PSMA) PET/CT and investigate the relationship between serum alpha-fetoprotein and PET scan parameters in patients with hepatocellular carcinoma. Methods: Fourteen patients were recruited after dynamic magnetic resonance imaging (MRI) of the upper abdomen, and 18 F-FDG and 68 Ga-PSMA PET/CT imaging studies were conducted. Regions of interest (ROIs) were drawn from lesion-free liver tissue, abdominal aorta (A), and right medial gluteal muscle (G) for the background activity. Maximum standard uptake value (SUV max ) of these regions were compared with the SUV max of primary tumor (T). Results: On visual assessment, five patients (36%) experienced low 18 F-FDG uptake in the primary lesion, three patients (21%) experienced moderate uptake, and six patients (43%) experienced high uptake. However, only one patient (7%) showed low 68 Ga-PSMA uptake, two patients (14%) showed moderate uptake, and 11 patients (79%) showed high uptake. Four patients with a low 18 F-FDG uptake showed high 68 Ga-PSMA uptake, while one patient exhibited low uptake with both 18 F-FDG and 68 Ga-PSMA. The number of lesions on 68 Ga-PSMA PET/CT and MRI was significantly higher than 18 F-FDG PET/CT (p=0.042 and 0.026, respectively). T/A and T/G values were significantly higher in 68 Ga-PSMA than 18 F-FDG (p=0.002 and 0.002, respectively). Conclusion: 68 Ga-PSMA PET/CT is superior to 18 F-FDG PET/CT in the staging of hepatocellular carcinoma. High 68 Ga-PSMA uptake could be promising for PSMA-targeted radionuclide treatments.

PSMA Radioligand Uptake as a Biomarker of Neoangiogenesis in Solid Tumours: Diagnostic or Theragnostic Factor?

“…Five full-text papers assessing the potential role of PSMA radioligands in the diagnostics of hepatocellular carcinoma (HCC) were reviewed [ 64 , 65 , 66 , 67 , 68 ]. Out of the five included studies, four had a prospective design [ 64 , 65 , 66 , 68 ]. The sample size varied from 7 to 40 and from 37 to 142 for patient and lesion analyses, respectively.…”

“…In all studies, PET/CT was performed using 68 Ga-PSMA-11 as the diagnostic radiopharmaceutical [ 64 , 65 , 66 , 67 , 68 ].…”

“…With regard to the clinical setting in which PSMA radioligand imaging was employed, in all studies PET/CT had the purpose both to stage untreated HCC patients and to restage after at least one line of treatment (transarterial chemoembolization, surgery, radiofrequency or transarterial radioembolization) [ 64 , 65 , 66 , 67 , 68 ].…”

PET-CT in Clinical Adult Oncology: III. Gastrointestinal Malignancies

“…Other PET tracers, such as 18 F choline, have been shown to have improved performance over FDG PET for well-differentiated HCC [ 34 , 35 ]. Several recent reports support that PSMA PET ligands may be of value in imaging HCC, including well-differentiated forms [ 36 , 37 , 38 , 39 ]. PSMA PET-CT, typically used in prostate cancer, is potential marker of neovascularity in the HCC and a potential future theragnostic target for HCC.…”

Role of Peptides in Diagnostics

“…Nevertheless, several PET and SPECT studies with radiolabeled PSMAPET radiotracers were also performed in patients with thyroid cancer [83], hepatocellular carcinoma [84], prostate adenocarcinoma [85], glioblastoma [86], myeloma [87], sinonasal glomangioperi-cytoma [88], Sjögren syndrome [89], and bladder cancer [90], which shows PSMA-targeted radiotracers are now playing an increasing role in the diagnostic imaging of patients.…”