FIGURE 4.

(A) ¹⁸F-FDG lymphography images (tumor not in field of view, mouse positioned prone, fur and skin removed, acquisition time of 5 min) showing stepwise Cerenkov-guided resection of metastatic (red circles) popliteal lymph node and corresponding contralateral healthy control node (blue circles) of mouse implanted with B16F10 tumor on right hind paw. At 1.5 h after bilateral ¹⁸F-FDG injection (3.7 MBq per side), metastatic node can still be identified by its subtle Cerenkov signal (mean signal-to-background ratio over time, 1.21 ± 0.14), whereas contralateral healthy control node does not show residual Cerenkov radiation (mean signal-to-background ratio over time, 0.69 ± 0.13), allowing for differentiation between the two and potential selective resection of tumor-bearing nodes. Asterisk indicates ¹⁸F-FDG pooling in bladder. (B) Healthy, uninvolved node displayed for size comparison. (C) H&E staining provides evidence of metastatic involvement of tumor side of popliteal lymph node by melanin-containing cells.