Review Article: Functional MRI for Quantitative Treatment Response Prediction in Locally Advanced Rectal Cancer.

Br J Radiol. 2017 Jan 05;:20151078

Authors: Pham TT, Liney GP, Wong K, Barton MB

Abstract
Despite advances in multi-modality treatment strategies for locally advanced rectal cancer and improvements in loco-regional control, there is still a considerable variation in response to neo-adjuvant chemo-radiotherapy (CRT). Accurate prediction of response to neo-adjuvant CRT would enable early stratification of management according to good responders and poor responders, in order to adapt treatment to improve therapeutic outcomes in rectal cancer. Clinical studies in diffusion weighted imaging (DWI) and dynamic contrast enhanced (DCE) MRI have shown promising results for the prediction of therapeutic response in rectal cancer. DWI allows for assessment of tumour cellularity. DCE enables evaluation of factors of the tumour micro-vascular environment, and changes in perfusion in response to treatment. Studies have demonstrated that predictors of good response to CRT include lower tumour pre-CRT ADC, greater percentage increase in ADC during and post-CRT, and higher pre-CRT K(trans). However, mean ADC and K(trans) values do not adequately reflect tumour heterogeneity. Multi-parametric MRI using quantitative DWI and DCE in combination, and a histogram analysis technique can assess tumour heterogeneity and its response to treatment. This strategy has the potential to improve the accuracy of therapeutic response prediction in rectal cancer and warrants further investigation.

PMID: 28055248 [PubMed - as supplied by publisher]