Figure 1.

FDG PET and FLT-PET imaging in dogs with metastatic melanoma tumor showing PET uptake before and diminished uptake after immunotherapy with intratumoral immunocytokine injections. Of note, there is increased reactive PET uptake in the nonmetastatic, reactive regional lymph node, which can be a reference for positive antitumor immune response (reproduced with permission, courtesy of David Vail, D.V.M., University of Wisconsin School of Veterinary Medicine).³⁹