Tumor Lesion Uptake of [ 177 Lu]Lu-DOTA-Rituximab in Skeletal and Splenic Disease in Diffuse Large B-Cell Lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma, and a sizable fraction of the DLBCL patients presents with advanced, relapsed, and refractory disease, demonstrating poor response to standard chemotherapy regimens. Radioimmunotherapy (RIT) has shown to be clinically effective in refractory DLBCL. We present the case of a patient with DLBCL with [ 18 F]FDG-avid widespread skeletal as well as splenic involvement as poor prognostic extranodal disease on FDG PET/CT. RIT based on [ 177 Lu]Lu-DOTA-rituximab was explored to study the biodistribution and dosimetry of [ 177 Lu]Lu-DOTA-rituximab in CD20-positive lymphoma. An exceptionally high tracer concentration in skeletal and splenic disease was observed, supporting its potential RIT application in relapsed and refractory DLBCL patients in the future.