[Transanorectal ultrasonography in the evaluation of extension and the monitoring of epidermoid cancers of the anus treated by radiation or chemotherapy]

Abstract

Twenty-five consecutive patients (5 men and 20 women) with squamous cell anal carcinoma were evaluated by transanorectal ultrasonography (TRUS). The patients were treated with radiotherapy alone (6 cases) or combined concomitant radiotherapy and chemotherapy (19 cases). The ultrasound findings were compared with clinical stage as assessed by digital examination and with pelvic computed tomography. Four tumors in clinical stage T2 showed evidence of external sphincter involvement at ultrasound (UT3) and one tumor in clinical stage T1 showed an invasion of the internal sphincter at ultrasound examination. Low echogenic, rounded structures, interpreted as enlarged lymph nodes, were identified in 8 cases at ultrasound but were not seen with computed tomography. Ultrasonograms were also obtained one month after the achieved end of radiation. Correct staging was by TRUS and CT in 92% and 72% of cases respectively. When combining clinical stage with TRUS, all tumors classified as T1-T2, UT1, UT2 had a complete response to radiotherapy with or without concomitant chemotherapy. TRUS could be a useful adjunct to digital palpation in initial staging and in follow-up after medical treatment of anal canal carcinoma.