Multiparametric MRI as an outcome predictor for anal canal XXXX managed with chemoradiotherapy.

@entity1 @entity957 @entity137 @entity5
BACKGROUND: Organ-preserving chemo-radiotherapy (CRT) is the standard of care for non-metastatic @entity957 (SCC). The optimal dosing schedules are yet to be determined. To improve local control rates, dose escalation has been investigated but found to not increase efficacy at the expense of increased @entity137 for an unselected @entity1 population. Diffusion weighted imaging (DWI) and dynamic contrast enhanced (DCE) Magnetic Resonance Imaging (MRI) performed during CRT have early data suggesting it to be an effective tool in predicting @entity5 response for SCC in related body sites. By performing multi-parametric MRI (mpmMRI) incorporating standard morphological, DWI and DCE sequences, we aim to determine whether the early changes in multi-parametric parameters during CRT can predict for later response in anal SCC. This may create opportunities to investigate treatment adaptation, either intensification or de-escalation, during CRT. METHODS/DESIGN: This protocol describes a prospective non-interventional multi-centre single-arm clinical trial. Twenty eligible @entity1 with histologically confirmed non-metastatic anal SCC will receive standard definitive CRT and undergo multi-parametric MRI's at the following 4 time points; prior to treatment, during the second and fourth weeks of treatment and 6-8 weeks following treatment. Complete response will be defined by the absence of @entity5 persistence or recurrence as determined by clinical examination at 6  months. Images will be retrospectively analysed to determine the apparent diffusion coefficient and @entity5 perfusion coefficients (Ktrans and Kep) at each time point. The Mann-Whitney-Wilcoxon Test will be used compare the change in these parameters for responder's verses non-responders. DISCUSSION: If validated, mpmMRI, along with other risk factors, can be used to stratify @entity1 and guide radiation dosing in a prospective trial. Informed individualisation of treatment intensity should help us achieve our goals of improved efficacy and reduced @entity137 . TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12614001219673 (19/11/2014).
