FIGURE 1. Patient 5, with NSCLC in left upper lobe. (A) Transaxial ¹⁸F-FLT PET scan demonstrates high ¹⁸F-FLT uptake (arrow) in tumor margin. ¹⁸F-FLT uptake in vertebral column, scapula, and ribs represents proliferating bone marrow. (B and C) Corresponding ¹⁸F-FDG PET and CT scans show high ¹⁸F-FDG uptake in tumor margin and primary lung tumor. (D) On Ki-67 immunohistochemistry, Ki-67–positive nuclei (brown) demonstrate high proliferation rate of 54%, and hematoxylin background staining reveals Ki-67–negative nuclei (blue).