Dynamic contrast-enhanced magnetic resonance imaging of tumor interstitial fluid pressure

Background and purposeHigh interstitial fluid pressure (IFP) in the primary tumor has been shown to promote metastasis in melanoma xenografts and to predict for poor survival in cervical cancer patients. The potential usefulness of gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA)-based dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for assessing tumor IFP noninvasively was investigated in the present study.Materials and methodsA-07 and R-18 melanoma xenografts with and without necrotic regions were subjected to DCE-MRI and subsequent measurement of IFP. Tumor images of E·F (E is the initial extraction fraction of Gd-DTPA and F is blood perfusion) and λ (λ is proportional to extracellular volume fraction) were produced by Kety analysis of DCE-MRI series.ResultsIn tumors without necrosis, significant inverse correlations were found between E·F and IFP, both for A-07 and R-18 tumors, and between λ and IFP for A-07 tumors. Significant correlations beween E·F and IFP or between λ and IFP could not be detected for tumors with necrotic regions.ConclusionsDCE-MRI may be developed to be a useful noninvasive method for assessing IFP in tumors without necrosis. This possibility warrants further studies involving several physiologically different experimental tumor lines, as well as human tumors.