Advanced MR Imaging for Early Biologic Tumor Changes to Neoadjuvant Chemoradiation Treatment for Rectal Cancer

This is a pilot study of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI, aka
perfusion MRI) and diffusion-weighted MRI (DWI-MRI), herein referred to in combination as
advanced MRI (aMRI) in the investigation of early tumor response to standard multi-dose,
fractionated external beam radiotherapy (EBRT) of the pelvis given in the neoadjuvant
setting concurrent with chemotherapy as well as induction chemotherapy prior to
chemoradiotherapy or consolidation chemotherapy after chemoradiotherapy for primary rectal
adenocarcinoma. This protocol aims to expand upon the growing body of knowledge concerning
early changes in tumor neovascularity and cellular density as a potential biomarker of
therapy efficacy. It further aims to address the trend towards more refined treatment
stratification for lower risk tumors to avoid morbidity from potentially unnecessary
radiation, chemotherapy or even radical surgery, by assessing the earliest changes that
occur in microvasculature and perfusion and diffusion of water during this treatment to see
if these can be predictive of long-term efficacy of therapy.

Inclusion Criteria:

- Patients with primary locally advanced rectal adenocarcinoma (0-18cm from the anal
verge) confirmed by MSKCC pathologist and eligible to undergo chemoradiation and
surgical resection at MSKCC.

- Written informed consent

- Age equal to or greater than 21 years

- Willing and able to undergo all study procedures

- Patients must have a planned surgical resection of the rectum

Exclusion Criteria:

- Patients younger than 21 years

- Pregnant and nursing women

- Contraindications for MRI (such as claustrophobia, pacemaker, non MR-compatible
artificial heart valves, cochlear implants, surgical clips in the brain, metal
fragments in eye)

- Estimated GFR (using Cockcroft formula Appendix 2) less than 30 ml/min/1.73m2 (FDA
advises caution in using gadolinium-based contrast agents in patients with severe
renal impairment).

- History of allergic reaction to MR contrast media

- Inability to give informed consent in person