Early detection of local RFA site recurrence using total liver volume perfusion CT initial experience.

Rationale And Objectives: The aim of this study was to prospectively evaluate the feasibility of a novel total liver volume perfusion computed tomographic technique in demonstrating treatment-site recurrence of liver metastases after radiofrequency ablation (RFA).

Materials And Methods: Eleven patients considered to be at increased risk for local RFA-site tumor recurrence underwent both positron emission tomography (PET) and perfusion computed tomography (CTP): a 12-phase scan of the entire liver acquired before and 11 times after contrast injection. After coregistration, blood flow maps were created using the maximum slope method.

Results: In all cases, the CTP-derived blood flow maps fully paralleled the PET images in showing either the absence (nine of 13 lesions) or presence (four of 13 lesions) of local RFA-site recurrence. Marginal lesions with high hepatic arterial perfusion (>50 mL/min/100 g) and low portal venous perfusion (<10 mL/min/100 g) represented recurring vital tumor tissue (P < .05).

Conclusion: Total liver volume CTP seems feasible for the detection and localization of treatment-site recurrence after RFA.