Figure 3.

Maximum-intensity projection image (A), axial ¹²⁴I-labeled chimeric monoclonal antibody G250 (¹²⁴I-cG250) positron emission tomography (PET) images (B and E), axial attenuation correction non-contrast-enhanced computed tomography (CT) for ¹²⁴I-cG250 PET localization (C and F), and fused axial ¹²⁴I-cG250 PET/CT images (D and G) demonstrating significant ¹²⁴I-cG250 activity in the superior portion of the right kidney (A, B, and D; red arrows) that corresponds to the mass seen on the prior diagnostic contrast-enhanced CT of the abdomen in Figure 1. Note that there is little to no ¹²⁴I-cG250 accumulation in the normal kidney (B, D, E, and G; blue arrows). Additionally, on ¹²⁴I-cG250 PET/CT imaging, there is increased focal ¹²⁴I-cG250 activity within a small retroperitoneal lymph node (A, E, and G; yellow arrows), which was not originally identified in the initial interpretation of the prior diagnostic contrast-enhanced CT of the abdomen or the ¹⁸F-fluorodeoxyglucose PET/CT. This small retroperitoneal lymph node (A, E, F, and G; yellow arrows) was later successfully identified and resected with the aid of a laparoscopic gamma detection probe at the time of laparoscopic right radical nephrectomy and retroperitoneal lymph node dissection.