Indium 111-labeled leukocyte scintigraphy in evaluating head and neck infections

This retrospective study looked at the role of indium 111-labeled white blood cell (111In WBC) scintigraphy in head and neck infections. The efficacy of 111In WBCs was compared to gallium 67 citrate (67Ga) and technetium Tc99m methylene diphosphonate (99mTc MDP) scintigraphy in detecting and monitoring the resolution of infection. For 22 active infections, the sensitivities for 111In WBC, 67Ga, and 99mTc MDP scintigraphy were 94%, 56%, and 86%, respectively, and the specificities for 111In WBC, 67Ga, and 99mTc MDP scintigraphy were 100%, 43%, and 0%, respectively. For 8 successfully treated infections, all seven 111In WBC studies became negative after therapy, in as short an interval as 1 month. In contrast, all seven 99mTc MDP images remained positive for as long as 6 months after therapy. The seven 67Ga studies had variable results, with four (57%) remaining positive, including two (28%) positive at 6 months after therapy. These results suggest that 111In WBC scintigraphy should be the initial radionuclide imaging tool in detecting active head and neck infections because of its greater accuracy, and its ability to revert to normal much sooner than 67Ga or 99mTc MDP scintigraphs when applied to a subset of patients with resolved infections.