Imaging and targeted agents in gastrointestinal cancers: overview on perfusion- and diffusion-weighted magnetic resonance imaging and angiogenesis inhibitors

Abstract

The advent of new antitumoral agents targeting tumoral vascularity require a change of diagnostic strategy. Imaging modalities should aim at detecting treatmentinduced intratumoral changes as treatment success not necessarily leads to a substantial loss of tumor volume. The tumoral vasculature and cellular microstructure offer attractive diagnostic targets for functional magnetic resonance imaging (MRI)-techniques. Dynamic contrast-enhanced (DCE)-MRI demonstrates tissue perfusion and permeability and can be used as a pharmacodynamic indicator for the efficacy of antivascular treatment. Diffusion-weighted (DW)-MRI allows for tissue differentiation based on changes in tissular water mobility, acting as a surrogate marker for microstructural density. By its ability to differentiate intact tumoral tissue from necrosis, DW-MRI can be used for early assessment of tumor response to systemic treatment. The aim of this paper is to discuss the background, basic principles and potential applications of perfusion-and diffusion-MRI for follow-up of treatment with angiogenesis inhibitors.

Transcatheter Chemoembolization of Unresectable Hepatocellular Carcinoma: Current Knowledge and Future Directions

“…Therefore, the follow-up after TACE should preferentially be performed with functional imaging techniques like diffusion-weighted and perfusion-weighted MRI. These techniques permit to evaluate tumoral vascular and microstructural changes and allow to estimate the total amount of treatment-induced necrosis, and thus treatment efficacy [21] .…”