CT of malignant anal canal tumors.

Radiation therapy of malignant neoplasms of the anal canal has promising results in the majority of patients if the disease is limited at initial diagnosis. Computed tomography (CT), especially when performed with contrast material injected intravenously, is valuable in the pre- and posttreatment assessment of the anorectal musculature and perirectal nodes. The authors review the anatomy of the anorectal area and their experience with CT evaluation of anal canal cancer in a series of 26 patients. They also discuss their experience with treatment of this cancer in a series of 48 patients.