Use of technetium-99m as a radioactive label to study migratory patterns of leukocytes.

Technetium-99m had been used as a radioactive label to study the migratory patterns of neutrophils. In a previous in vitro study, neutrophils were labeled with Tc-99m and infused into patients with and without various hematological disorders. Increased pulmonary localization was detected by scintillation camera within 10 min; this decreased gradually within 3 hr. Accumulation was seen in the liver and spleen at 3 hr. The same results were noted by using neutrophils labeled with Tc-99m sulfur colloid. In a patient with severe ulceration in the oral cavity, due to acute leukemia, Tc-99m-labeled transfused neutrophils that were collected by filtration leukopheresis were concentrated in the infected lesions.