TC-99M LL-2 FAB' MONOCLONAL-ANTIBODY IMAGING IN ACQUIRED IMMUNE-DEFICIENCY SYNDROME-RELATED LYMPHOMA

BACKGROUND. Both systemic and primary central nervous system (CNS) non -Hodgkin's lymphomas (NHL) occur in people with acquired immune defici ency syndrome (AIDS). The radiographic manifestations may be similar t o other neoplasms and opportunistic infections that are also found fre quently in AIDS. Furthermore, these diseases may coexist with NHL in t he AIDS patient. METHODS. To evaluate the use of Tc-99m Lymphoscan (th e Fab' fragment of the anti-CD-22 antibody LL-2; Immunomedics, Inc., M orris Plains, NJ) in patients with suspected AIDS lymphoma, we studied 7 patients with 35 sites of suspected disease. Six had CNS lesions su spicious for parenchymal brain lymphoma. Each patient underwent planar and single photon emission computed tomography imaging at 3-5 and 18- 24 hours after administration of Lymphoscan. Scintigraphic results wer e compared with results of conventional diagnostic modalities. RESULTS . Overall, the sensitivity of Lymphoscan was 92% and the specificity w as 86%. In brain lesions, there was 100% sensitivity and 100% specific ity. Lymphoscan also had 100% sensitivity for sites of lymphomatous ly mphadenopathy and for liver involvement. Although less specific in ext racranial sites, Lymphoscan was correctly negative in sites of coexist ing adenocarcinoma and pneumonia. Two patients had both parenchymal CN S and systemic lymphoma proven by biopsy.CONCLUSIONS. Lymphoscan appea rs to be a sensitive and specific method for diagnosing CNS lymphoma i n AIDS patients. Although slightly less specific in extracranial sites , it may be helpful in differentiating lymphoma from other etiologies in these patients at risk for multiple neoplasms and opportunistic inf ections. (C) 1997 American Cancer Society.