Figure 1. Example of a CXCR4-positive, SSTR-negative SCLC patient.

Display of maximum intensity projections (upper row) and transaxial images (lower row) of both CXCR4- and SSTR-directed PET/CT (interval between both scans, 6 days) in a patient with recurrent SCLC (patient #3). Whereas [⁶⁸Ga]Pentixafor-PET demonstrates intense tracer retention in various tumor manifestations including mediastinal lymph nodes, bone and pleural lesions, SSTR-directed PET proves negative (arrows; insert: corresponding contrast-enhanced transaxial CT).