Whole-body and CT images after infusion of ¹³¹I-labeled chimeric 81C6 mAb. (A) Whole-body images of a patient obtained at different time points after infusion of 370 MBq ¹³¹I-labeled chimeric 81C6 mAb. Note the prolonged uptake in the nodal disease in the neck. (B) CT scan depicting the nodal disease (arrow) that accumulated the radiolabeled antibody. A biopsy sample was obtained from this node 44 hours after dosimetric infusion of 370 MBq, and the measured activity concentration was 70 kBq/g.