TY - JOUR T1 - Imaging of Experimental Colitis with a Radiolabeled Leukotriene B<sub>4</sub> Antagonist JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 89 LP - 93 VL - 45 IS - 1 AU - Julliëtte E.M. van Eerd AU - Peter Laverman AU - Wim J.G. Oyen AU - Thomas D. Harris AU - D. Scott Edwards AU - Charles E. Ellars AU - Frans H.M. Corstens AU - Otto C. Boerman Y1 - 2004/01/01 UR - http://jnm.snmjournals.org/content/45/1/89.abstract N2 - The use of radiolabeled leukocytes is considered the gold standard for scintigraphic imaging of inflammatory bowel disease. The disadvantages of 99mTc-hexamethylpropyleneamine oxime (HMPAO)-leukocytes, however, encourage the search for new imaging agents with at least similar diagnostic accuracy but without the laborious preparation and subsequent risk of contamination. In this study we investigated the imaging characteristics of a new imaging agent that specifically binds to the leukotriene B4 (LTB4) receptors expressed on neutrophils. Imaging characteristics of the 111In-labeled LTB4 antagonist (DPC11870) were compared with those of 18F-FDG and 99mTc-HMPAO-granulocytes in a rabbit model of experimental colitis. Methods: Acute colitis was induced in New Zealand White (NZW) rabbits by infusion of trinitrobenzene sulfonic acid in the descending colon. Forty-eight hours after induction of colitis, all animals were injected intravenously with 99mTc-granulocytes, 18F-FDG, or 111In-DPC11870. The pharmacokinetics and biodistribution were studied by serial scintigraphic imaging and by ex vivo counting of dissected tissues. Results: All 3 radiopharmaceuticals showed the inflamed colon as early as 1 h after injection. However, compared with 99mTc-granulocytes, both 111In-DPC11870 and 18F-FDG were superior in revealing the inflamed lesions. The biodistribution data showed that uptake of 111In-DPC11870 in the inflamed colon was highest (0.72 ± 0.18 percentage injected dose per gram [%ID/g]), followed by uptake of 99mTc-granulocytes (0.40 ± 0.11 %ID/g) and of 18F-FDG (0.16 ± 0.04 %ID/g). Because of low activity concentrations in the noninflamed colon, the radiolabeled LTB4 antagonist also revealed the highest ratio of affected colon to unaffected colon (11.6 for 111In-DPC11870, 5.5 for 99mTc-granulocytes, and 4.1 for 18F-FDG). Conclusion: The radiolabeled LTB4 antagonist DPC11870 clearly delineated acute colitis lesions in NZW rabbits within 1 h after injection. Because of high uptake in the inflamed lesions and a low activity concentration in the noninflamed colon, images acquired with 111In-DPC11870 were better than those acquired with 99mTc-granulocytes or 18F-FDG. ER -