Perfusion CT as a Predictor of Treatment Response in Patients With Rectal Cancer

Recent advances in computed tomography (CT) technology have made CT perfusion imaging feasible for the assessment of tumor perfusion in solid tumors of the abdomen. CT perfusion has shown promising results in serving as a noninvasive method of predicting response to therapy in cancer patients. CT perfusion parameters have also been found to correlate with immunohistologic markers of angiogenesis in a number of solid tumors, suggesting a possible role for CT perfusion as a noninvasive biomarker of tumor angiogenesis. The goals of the investigators study are twofold: first, to determine the relationship between baseline CT perfusion characteristics of rectal cancers and their response to treatment, and second, to determine if perfusion CT can be used to subsequently monitor tumor response to treatment. The investigators hope to enroll those patients with locally advanced rectal cancer undergoing standard CT for pre-treatment planning, integrating CT perfusion imaging into the current abdomen/pelvis imaging protocol with close clinical and radiologic follow-up after treatment to determine response to therapy and time to disease progression.

Inclusion criteria

• Patients with suspected or biopsy-proven, locally advanced rectal cancer will be eligible for enrollment.
• Patients must be 18 years or older. Patients must not be pregnant and, if of child-bearing age, must take precautions not to become pregnant.
• No life expectancy restrictions.
• ECOG and Karnofsky Performance Status will not be employed.
• Patients with renal failure are ineligible for this study (GFR must be > 60)
• Ability to understand and willingness to sign a written informed consent document.

Exclusion criteria

• Patients who have undergone prior treatment for rectal cancer are ineligible for enrollment.
• No restrictions regarding use of other investigational agents.
• Patients with severe contrast allergy are ineligible.
• Patients who are pregnant or are trying to become pregnant are excluded from this study.
• Patients who are cancer survivors or HIV-positive will not be excluded.