Accumulation of indium-111-labeled granulocytes in malignant tumors.

In a retrospective study of 220 [111In]granulocyte scintigrams from 208 patients, 25 patients had malignant neoplasms. Among these, tumor uptake of 111In activity was observed in ten patients (intense activity in two patients with non-Hodgkin's lymphoma and colonic carcinoma, respectively; moderate uptake in a patient with non-Hodgkin's lymphoma, and in a patient with an ovarian carcinoma; weak activity in three patients with cerebral neoplasms; and activity within otherwise "cold" metastatic lesions of the liver in three patients). Microscopic investigation following specific granulocyte staining revealed the greatest extent of granulocyte infiltration in the tumors which took up 111In activity, emphasizing the importance of tumor granulocyte infiltration as the single most important factor underlying tumor accumulation of 111In activity during [111In]granulocyte scintigraphy.