(18)F-FDG PET/CT total lesion glycolysis is associated with circulating tumor cell counts in patients with stage I to IIIA non-small cell lung cancer

BACKGROUND: In non-small cell lung cancer (NSCLC), (18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG) uptake determined by PET and presence of circulating tumor cells (CTCs) in the peripheral blood independently predict outcomes. For (18)F-FDG PET/CT staging interpretation, standardized uptake values (SUV(max/avg)) are routinely used in clinical reporting. The goal was to investigate whether (18)F-FDG uptake measured by SUV(max/avg), but also measures of metabolic tumor volume (MTV) and total lesion glycolysis (TLG) (MTV × SUV(avg)), are associated with CTCs. METHODS: Prospectively, 7.5 mL blood was drawn from NSCLC patients at the time of staging 18F-FDG PET/CT and from healthy control subjects. CTCs were identified by immunofluorescent staining (CK8/18/19(pos)/EpCAM(pos)/CD45(neg)/DAPI(pos) nucleus). (18)F-FDG PET/CTs were analyzed for SUV(max), SUV(avg), MTV, and TLG. RESULTS: In 16 NSCLC patients with stage I–IIIA, MTV and TLG, in contrast to SUV(max) and SUV(avg), were positively associated with CTCs (linear regression analysis). No CTCs were detectable in 20 healthy control subjects. CONCLUSIONS: This pilot study demonstrates that (18)F-FDG PET/CT TLG correlates with CTCs in NSCLC patients without distant metastases. TLG might be a more appropriate marker for hematogenous micrometastatic potential than SUVs.