Decreased blood flow with increased metabolic activity: a novel sign of pancreatic tumor aggressiveness.
OBJECTIVE
To study blood flow (BF) and metabolism in normal pancreas and in different pancreatic lesions. We then determined the effect of these biomarkers on outcome in patients with pancreatic cancer.


METHODS
Oxygen-15-labeled water and fluorodeoxyglucose positron emission tomography/computed tomography scans were used in 26 patients with a suspicion of pancreatic cancer to measure pancreatic BF and metabolism. In addition, the ratio of standardized uptake value to BF (SUV/BF) was calculated. Patients were divided into three groups: patients with a finding of normal pancreas (n = 7), benign lesions (n = 8), and malignant tumors (n = 11).


RESULTS
Patients with benign and malignant pancreatic tumors had decreased BF of the lesion by 48% and 60%, respectively, compared with patients with normal pancreatic tissue. SUV(max) was 3-fold higher in malignant tumors compared with both benign lesions and normal pancreas (P < 0.05). In contrast, the SUV(max) of patients with benign lesions and normal pancreas did not differ. The SUV/BF ratio was significantly higher in malignant lesions than in benign lesions or in patients with normal pancreas (P < 0.05). In patients with cancer, high SUV/BF ratio was a stronger predictor of poor survival compared with high metabolism or lower-than-normal pancreatic BF.


CONCLUSIONS
BF in pancreatic cancer is significantly reduced compared with the normal pancreas, which may in part explain the poor success of both radiotherapy and chemotherapy. We suggest that the composite measurement of BF and metabolism in pancreatic cancer could serve as a novel tool in the planning of treatments targeting vasculature.
Komar
Gaber
G
Turku PET Centre, University of Turku, Turku, Finland. gaber.komar@utu.fi
Kauhanen
Saila
S
Liukko
Kaisa
K
Seppänen
Marko
M
Kajander
Sami
S
Ovaska
Jari
J
Nuutila
Pirjo
P
Minn
Heikki
H
D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010179:Pancreas / Q000098:blood supply / Q000378:metabolism / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000098:blood supply / Q000378:metabolism / Q000473:pathology*; D049268:Positron-Emission Tomography; D011379:Prognosis; D012039:Regional Blood Flow
D014408:Biomarkers, Tumor; D019788:Fluorodeoxyglucose F18; D005947:Glucose