Immunoscore in Rectal Cancer

A tumor sample from the diagnostic biopsy and surgical procedure will be used for research.

At the end of a standard MRI, we will perform IVIM, which is a diffusion-weighted imaging sequence that simultaneously characterizes the microscopic diffusivity of water and the macroscopic transport of water via bulk flow. IVIM may more accurately reflect the properties of the tumor microenvironment including vascular permeability, interstitial fluid pressure, and response to neoadjuvant therapy.

Following a standard MRI scan, Dynamic Contrast Enhanced MRI (DCE-MRI) will be done. DCE-MRI is an indicator-dilution experiment in which the delivery and transcapillary transfer of a contrast agent, typically one of a number of gadolinium-based contrast agents (GBCA), is used to assess a number of parameters characterizing tissue physiology. In locally advanced rectal cancer patients, use of DCE-MRI for determining pathologic response has produced equivocal results but more promising data has been published recently in the cervical cancer literature.

RNA will be collected from biopsy and surgical tissue for gene expression analysis.