Gene Expression and FDG PET/MRI in Evaluating Treatment Response in Patients With Locally Advanced Rectal Cancer Undergoing Chemotherapy and Radiation Therapy Before Surgery

Pilot Study of Gene Expression and FDG-PET/MR Biomarkers for Evaluation of Response to Neoadjuvant Therapy for Locally Advanced Rectal Cancer

This pilot clinical trial studies gene expression analysis and fludeoxyglucose F 18 (FDG) positron emission tomography (PET)/magnetic resonance imaging (MRI) in evaluating treatment response in patients with rectal cancer that has spread to nearby tissue or lymph nodes undergoing chemotherapy and radiation therapy before surgery. Studying samples of tissue in the laboratory may help doctors learn more about changes that occur in deoxyribonucleic acid (DNA) and may also help doctors predict a patient's response to treatment before surgery. PET-MRI is a procedure that combines the pictures from a PET scan and an MRI scan. The combined scans give more detailed pictures of areas inside the body than either scan gives by itself. PET-MRI may help determine how well people respond to pre-surgery chemotherapy and radiation therapy and help the surgeon make the best plan for removal of the tumor.

Inclusion Criteria:

• Biopsy-proven adenocarcinoma of the rectum.
• Surgical candidate.
• Candidate for neoadjuvant chemotherapy.
• Clinical evidence of T1-3N1 or T3N0 disease. This can be either by imaging studies or by physical exam findings.
• At least 18 years of age.
• Zubrod performance status of 0-2.
• Able to understand and willing to sign a written informed consent document.
• Patients with distant metastatic disease will be eligible if they satisfy all other conditions.

Exclusion Criteria:

• Pregnant.
• Past history of pelvic radiotherapy.
• Received prior chemotherapy for colorectal cancer.
• Uncontrolled diabetes with a fasting glucose ≥ 200 mg/dl at the time of PET/MRI imaging.
• Claustrophobia or any other contraindication to MRI imaging evaluated by a standardized safety questionnaire.
• Renal insufficiency (defined as glomerular filtration rate (GFR < 30 mL/min/1.73 m2) measured no more than 60 days before the first research scan) which precludes safe administration of the contrast agent.
• Currently on dialysis.
• Known prior allergic reaction to gadolinium-based MR contrast agents.