Feasibility of 18F-FDG combination with 68Ga-citrate PET/CT in the diagnosis of inflammatory bowel disease - First results

Objectives Inflammatory bowel disease, including Crohn's disease and Ulcerative colitis, is mainly detected by the invasive endoscopy in clinical. 68Ga-citrate, an imaging agent towards inflammation used recently, is used in osteomyelitis. The purpose of this study was to detect the feasibility of 18F-FDG PET/CT combination with 68Ga-citrate PET/CT in the diagnosis of Inflammatory Bowel Disease.

Methods After giving informed consent, 16 patients with suspected inflammatory bowel disease were prospectively evaluated. 18F- FDG PET/CT was performed at 45min after i.v. injection of 18F- FDG. 68Ga-citrate PET/CT was acquired at 90min after injection of 68Ga-citrate. We evaluated 18F- FDG and 68Ga-citrate uptake visually and semiquantitatively using standardized uptake values (SUVmax). Meanwhile endoscopy and biopsy was performed.

Results Nine of 16 patients were confirmed histologically: 5 Crohn's disease, 3 ulcerative colitis, 1 lymphoma. Both the lesion of ulcerative colitis and Crohn's disease showed moderate- high uptake of 18F-FDG. The mean±SD of standardized uptake values was 7.83±3.56.The lesion of Crohn's disease presented mild uptake of 68Ga-citrate. The mean±SD of standardized uptake values was 2.76±0.28; The lesion of ulcerative colitis showed moderate uptake of 68Ga-citrate. The mean±SD of standardized uptake values was 4.47±1.10.

Conclusions The result of this clinical study suggest that18F-FDG PET/CT can detect the lesion of colon, while 68Ga-citrate PET/CT may distinguish between Crohn's disease and ulcerative colitis. Further exploration of this modality should be performed.