Introduction: Blood perfusion of liver metastases can be non-invasively assessed by dynamic contrast enhanced magnetic resonance imaging (DCE-MRI). The aim of this study was to explore whether the ratio of hepatic arterial to total liver blood flow (Hepatic Perfusion Index-HPI) and the area under the enhancement curve (AUC) of selected liver areas in patients with hepatic metastases from colorectal cancer treated with first-line chemotherapy could predict response and/or be a prognostic variable.
Patients and methods: Sequential liver DCE-MRI studies with morphological imaging reconstruction were performed in 43 consecutive patients at baseline and every 3 months during oxaliplatin-based first-line chemotherapy. Data about HPI of the whole liver, and AUC of metastatic and healthy areas were calculated at each time-point and compared both at baseline and sequentially during the treatment.
Results: Baseline HPI and AUC values did not discriminate patients responsive to chemotherapy, nor those with better survival outcomes. HPI and AUC values at 3 months decreased significantly more in responders than non-responders. AUCs calculated from areas of the liver with or without neoplastic lesions varied consistently, being increased in progressing patients and decreased in responding patients.
Discussion: Our results did not support the hypothesis of a predictive or prognostic role of HPI and AUCs calculated by DCE-MRI in liver metastatic CRC patients, thus the primary endpoint of the study was not reached. However, reduced arterial blood flow in metastatic liver can be obtained by chemotherapy alone, without any anti-angiogenic agent; interestingly, HPI and AUC data suggest a possible relationship between tumor metabolism and entire liver perfusion.
Keywords: AUC; DCE-MRI; HPI; Liver blood flow; Metastatic colorectal cancer.