Demonstrating Intertumoural Differences in Vascular-Metabolic Phenotype with Dynamic Contrast-Enhanced CT-PET

Abstract EN

Purpose.

To assess whether the differences in vascular-metabolic relationships between lymphoma masses and colorectal liver metastases predicted from previous histopathological studies can be demonstrated by dynamic contrast-enhanced CT (DCE-CT) combined with fluorodeoxyglucose positron emission tomography (FDG-PET).

Methods.

DCE-CT and FDG-PET studies were drawn from an imaging archive for patients with either lymphoma masses (n=11) or hepatic metastases from colorectal cancer (CRM: n=12).

Tumour vascularity was assessed using DCE-CT measurements of perfusion.

Tumour glucose metabolism was expressed as the mean FDG Standardised Uptake Value (SUVFDG).

The relationship between metabolism and vascularity in each group was assessed from SUVFDG /perfusion ratios and Pearson correlation coefficients.

Results.

An SUVFDG threshold of 3.0 was used to designate lymphoma masses as active (AL, n=6) or inactive lymphoma (IL, n=5).

Tumour perfusion was significantly higher in AL (0.65 mL/min/mL) than CRM (0.37 mL/min/mL: P=.031) despite similar SUVFDG (5.05 and 5.33, resp.).

AL demonstrated higher perfusion values than IL (0.24 mL/min/mL: P=.006).

SUVFDG/perfusion was significantly higher in CRM (15.3 min) than IL (4.2 min, P<.01).

There was no correlation between SUVFDG and perfusion for any patient group.