The purpose of this study is to see how CT virtual proctoscopy compares to an ultrasound
exam of the rectal area in determining the stage of rectal cancer for people recently
diagnosed with rectal cancer. This study will also compare tumor volume before and after
neoadjuvant therapy using CT virtual proctoscopy, with the ultrasound exam as a comparison.
Neoadjuvant therapy consists of chemotherapy and radiation therapy. Neoadjuvant
chemoradiation therapy is done before surgery to reduce the size of tumors.
- Patients who have been diagnosed with adenocarcinoma of the rectum, who have not
started their neoadjuvant treatment yet.
- Patients who have started their neoadjuvant therapy already