Comparison of reticuloendothelial scans with bone scans in malignant disease

Thirty patients with histologically proven malignant disease were selected for reticuloendothelial scans and bone scans because of suspected bone or bone marrow involvement. Reticuloendothelial scans were abnormal in 83% of the patients and bone scans were abnormal in 47%. Focal defects on the reticuloendothelial marrow scan correlated better with tumor infiltration of the marrow than did diffusely abnormal scans. Focal defects were found in nine patients (30% of total), four of whom had negative or equivocal bone scans. In multiple myeloma, reticuloendothelial marrow scans were more sensitive than bone scans, but were not clearly better than bone scans in patients with solid tumors. In the interpretation of reticuloendothelial scans, consideration must be given to the effects of radiation, chemotherapy, and uremia, all of which may cause decreased reticuloendothelial uptake and falsely positive reticuloendothelial scans. Reticuloendothelial scans seem most useful for hematologic malignancies that have not been previously treated. The advantages and disadvantages of reticuloendothelial scans are discussed.