FDG metabolism and uptake versus blood flow in women with untreated primary breast cancers

The aim of this study was to determine the relationship between tumor blood flow and glucose utilization in women with untreated primary breast carcinomas. Noninvasive determinations of blood flow and glucose utilization with positron emission tomography (PET) were performed in 101 regions of tumor from nine women with untreated primary breast carcinoma. [¹⁵O]H₂O PET scans of tumor blood flow were compared with fluorine-18 fluoro-2-deoxy-D-glucose (FDG) PET scans of tumor glucose metabolism. Modeling of multiple parameters was undertaken and flow and glucose utilization compared. Mean whole-tumor blood flow was 14.9 ml dl^-1 min^-1, but ranged from 7.6 to 29.2 ml dl^-1 min^-1. Mean whole-tumor standardized uptake value corrected for lean body mass, SUV-lean (50-60 min), was 2.32±0.19 while mean K_i was 1.2 ml dl^-1 min^-1 for FDG. SUV-lean and blood flow were strongly correlated (r=0.82, P=0.007) as were K₁ for FDG and flow (r=0.84, P=0.004). In these women with untreated breast cancers, FDG uptake (SUV-lean) and tumor blood flow are strongly correlated. The slope of FDG uptake versus blood flow appears higher at low flow rates, suggesting the possible presence of areas of tumor hypoxia.