Transvaginal sonography as an adjunct to endorectal sonography in the staging of rectal cancer in women.

OBJECTIVE: The purpose of this study was to evaluate the contribution of transvaginal sonography (TVS) in the staging of rectal cancer in women. MATERIALS AND METHODS: Sixty women with rectal tumors underwent TVS. Forty-five of the 60 women also underwent endorectal sonography. Forty-nine of the women had rectal carcinoma; nine, tubulovillous adenoma; and two, gastrointestinal stromal tumor confirmed at surgical pathologic examination (n = 41) and biopsy before chemoradiation therapy (n = 19). Four of the 49 rectal carcinomas were T1; seven, T2; 35, T3; and three, T4. Images from TVS and endorectal sonography were shown independently to two blinded reviewers, who staged the tumors and assessed examination adequacy for tumor presence, size, and depth and nodal status. Staging results with TVS were compared with those obtained with endorectal sonography and histopathologic examination. RESULTS: All tumors were seen with TVS. In 30 of the 49 rectal carcinomas confirmed at surgical pathologic examination TVS tumor staging was accurate in 25 (83.3%) of the cases. Two (6.7%) of the 30 tumors were understaged, and 3 (10%) were overstaged. All tumors selected for chemoradiation (n = 19) were correctly staged T3. Endorectal sonography was suboptimal for tumors that were stenotic (n = 3), large (n = 2), high at the rectosigmoid junction (n = 4), or low at the anal canal (n = 3). In these 12 cases, TVS successfully depicted the lesion, and the images gave enough information for prediction of stage. In interpretation of the images of 45 patients who underwent both TVS and endorectal sonography, the blinded reviewers had good agreement and comparable accuracy for staging in adequate examinations with each technique. Four of the nine villous adenomas were overstaged as T1 on TVS. Gastrointestinal stromal tumors manifested as intramural vascular masses. CONCLUSION: TVS is an excellent adjunct to endorectal sonography in the staging of rectal cancer in women. It helps resolve the findings after endorectal sonography has been unsuccessful because the tumors are stenotic or in a high or low position.