TC-99M LEUKOCYTE IMAGING FOR EVALUATING DISEASE SEVERITY AND MONITORING TREATMENT RESPONSE IN ULCERATIVE-COLITIS - COMPARISON WITH COLONOSCOPY

The diagnostic value of Tc-99m leukocyte imaging for evaluating diseas e activity and monitoring treatment response in ulcerative colitis was compared with that of colonoscopy. A total of 48 studies were perform ed in 28 patients with ulcerative colitis. Forty-six studies had both Tc-99m leukocyte imaging and colonoscopy within 2 weeks of each other, and the remaining two studies had only Tc-99m leukocyte imaging. In 4 6 studies, semiquantitative grading of colonic radioactivity by compar ison with iliac crest marrow activity on radionuclide imaging correlat ed well with macroscopic grading based on Matts' criteria on colonosco py, Fourteen (82%) of 17 studies with slight colonoscopic change showe d a negative result on the radionuclide image. In 15 patients treated with glucocorticoids or leukapheresis, radionuclide imaging showed nea rly the same statistical results as colonoscopy in monitoring treatmen t response. Tc-99m leukocyte imaging could be used as an alternative t o colonoscopy to evaluate the disease activity of ulcerative colitis o r to monitor the treatment response, although it is insensitive for de tecting disease with only slight macroscopic changes.