This prospective study aimed to compare the diagnostic performance of (18)F-fluorocholine and (18)F-FDG for detecting and staging hepatocellular carcinoma (HCC) in patients with chronic liver disease and suspected liver nodules.
Methods: Whole-body PET/CT was performed in a random order at 10 min after injection of 4 MBq of (18)F-fluorocholine per kilogram and at 1 h after injection of 5 MBq of (18)F-FDG per kilogram. PET/CT results were read in a masked manner by 2 specialists, and diagnostic performance was assessed from the results of consensus masked reading. Those focal lesions appearing with increased or decreased activity, compared with background, on (18)F-fluorocholine PET/CT were considered positive for malignancy. The standard of truth was determined on a per-site basis using data from a histologic examination and a follow-up period of more than 6 mo; on a per-patient basis, the Barcelona criteria were also accepted as a proof of HCC in 5 patients.
Results: Eighty-one patients were recruited; standard of truth was determined in 59 cases. HCC was diagnosed in 34 patients. Therefore, sensitivity was 88% for (18)F-fluorocholine and 68% for (18)F-FDG (P = 0.07), and in 70 sites, sensitivity was 84% for (18)F-fluorocholine, significantly better than the 67% for (18)F-FDG (P = 0.01). Of the 11 patients with well-differentiated HCC, 6 had a positive result with (18)F-fluorocholine alone, whereas (18)F-FDG was never positive alone; corresponding site-based sensitivity was 94% for (18)F-fluorocholine and 59% for (18)F-FDG (P = 0.001). The detection rate of 18 sites corresponding to other malignancies was 78% for (18)F-fluorocholine and 89% for (18)F-FDG. In nonmalignant sites, (18)F-fluorocholine appeared less specific than (18)F-FDG (62% vs. 91% P < 0.01) because of uptake by focal nodular hyperplasia.
Conclusion: (18)F-fluorocholine was significantly more sensitive than (18)F-FDG at detecting HCC, in particular in well-differentiated forms. In contrast, (18)F-FDG appeared somewhat more sensitive at detecting other malignancies and was negative in focal nodular hyperplasia. Thus (18)F-fluorocholine appears to be a useful PET/CT tracer for the detection and surveillance of HCC; however, performing PET/CT with both radiopharmaceuticals seems to be the best option.