JNM: PET/CT + 18F-fluorocholine bests 18F-FDG for hepatocellular carcinoma detection
PET/CT with 18F-fluorocholine was significantly more sensitive than 18F-FDG at detecting hepatocellular carcinoma in well-differentiated forms in patients with cirrhosis or chronic liver disease, according to study results published in the November issue of the Journal of Nuclear Medicine.

Jean-Noël MD, PhD, from the department of nuclear medicine, Hopital Tenon, AP-HP and Universite´ Pierre et Maris Curie in Paris, and colleagues performed the prospective study to compare the diagnostic performance of PET/CT with 18F-fluorocholine and 18F-FDG for detecting and staging hepatocellular carcinoma in patients with chronic liver disease and suspected liver nodules.

Noël and colleaues performed whole-body PET/CT in a random order at 10 minutes after injection of 4 MBq of 18F-fluorocholine per kilogram and at one hour after injection of 5 MBq of 18F-FDG per kilogram.

Eighty-one patients were recruited for the study and standard of truth was determined in 59 cases. Hepatocellular carcinoma was diagnosed in 34 patients. Therefore, sensitivity was 88 percent for 18F-fluorocholine and 68 percent for 18F-FDG, and in 70 sites, sensitivity was 84 percent for 18F-fluorocholine, significantly better than the 67 percent for 18F-FDG, according to Noël and colleagues.

Of the 11 patients with well-differentiated hepatocellular carcinoma, six had a positive result with 18F-fluorocholine alone, whereas 18F-FDG never produced stand-alone positive results; corresponding site-based sensitivity was 94 percent for 18F-fluorocholine and 59 percent for 18F-FDG.

The researchers also found that the detection rate of 18 sites corresponding to other malignancies was 78 percent for 18F-fluorocholine and 89 percent for 18F-FDG. In nonmalignant sites, 18F-fluorocholine appeared less specific than 18F-FDG (62 vs. 91 percent) because of uptake by focal nodular hyperplasia.

The study confirmed that 18F-fluorocholine PET/CT was able to detect hepatocellular carcinoma in liver nodules, even of subcentimeter size, and demonstrated that 18F-fluorocholine was more sensitive than 18F-FDG for detecting well-differentiated hepatocellular carcinoma. In contrast, the sensitivity of 18F-fluorocholine and 18F-FDG PET/CT was not significantly different in the case of less differentiated hepatocellular carcinoma.

Thus 18F-fluorocholine appears to be a useful PET/CT tracer for the detection and surveillance of hepatocellular carcinoma; however, performing PET/CT with both radiopharmaceuticals seems to be the best option, concluded Noël and colleagues.