THE ROLE OF INTRARECTAL ULTRASOUND (IRUS) IN STAGING OF RECTAL-CANCERAND DETECTION OF EXTRARECTAL PATHOLOGY

intrarectal Ultrasound (IRUS) is rapidly becoming an effective tool in the staging of rectal cancer. Twenty-nine consecutive patients with a denocarcinoma of the rectum underwent both CT scanning and IRUS in the preoperative assessment of rectal cancer in an effort to correlate IR US staging with surgical pathology, correlate tumor staging comparing IRUS with CT scan, and determine incidence of extrarectal pathology by IRUS. Patients were reviewed as to IRUS stage, results of CT scan, TN M stage of extirpated tumor, incidence of genitourinary pathology, and sonographic result of preoperative radiotherapy (RT). The mean age of all patients was 69 years; there were 25 males and four females. Twen ty-four patients underwent proctectomy with either low pelvic anastomo sis or end stoma; five underwent local surgical therapy. Thirteen pati ents received preoperative RT. CT scan correlated poorly with IRUS sta ging of tumors penetrating the muscularis propria. IRUS overstaged 40 per cent, understaged 5 per cent, and correctly staged 55 per cent of patients when compared with pathological specimens. Eleven of the 25 m ales (44 per cent) had abnormal prostates by IRUS. Five (20%) had furt her urologic intervention, resulting in two prostatic cancers found. O ur data suggests that CT scan staging correlated poorly with IRUS stag ing. CT poorly determines depth of rectal tumor wall invasion. IRUS co rrelated well with pathology and understaged 5 per cent of patients be fore surgery. Genitourinary abnormalities were detected in a significa nt number of patients. IRUS is an effective modality for preoperative staging of rectal cancer. A significant number of genitourinary abnorm alities may be anticipated when employing preoperative IRUS. Staging w ith IRUS allows for effective surgical decision-making and strategies for preoperative adjuvant therapy.