Splenic Volume Change and Nodal Tumor Response in Non-Hodgkin's Lymphoma Patients after Radioimmunotherapy Using Radiolabeled Lym-1 Antibody

Splenomegaly is frequently found in non-Hodgkin's lymphoma (NHL) patients. This study evaluated the implications of splenic volume change in response to radioimmunotherapy (RIT) using radiolabeled Lym- 1 antibody. Methods: Twenty-nine NHL patients treated with radiolabeled-Lym-1 and 9 breast cancer patients, the reference group, treated with radiolabeled ChL6, BrE-3, or m170, were analyzed using X-ray computer tomography (CT) splenic images obtained before and after RIT. Patient-specific radiation doses to the spleen were determined using actual splenic volume determined by CT and body weight. Results: Of 29 NHL patients, 13 that had splenic volumes equal or less than 310 mL, there was little or no change in splenic volume after RIT, despite splenic radiation doses as high as 23.1 Gy (median 8.0 Gy). Similarly, in a reference group of 9 breast cancer patients, there was little or no change in splenic volume after RIT, despite doses as high as 14.4 Gy (median 11.5 Gy). In the remaining 16 NHL patients, spl...