The study states that transvaginal ultrasound shows superior imaging of the rectum and the surrounding tissues, better resolves rectal wall layers, and defines more clearly the extent of rectal cancer. It is also easily performed with the conventional ultrasound probes used for other gynecologic imaging. "The patients also prefer transvaginal ultrasound to transrectal ultrasound as it causes less discomfort," said Kavita Dhamanaskar, MD, the lead author of the study.
According to Dr. Dhamanaskar, transrectal ultrasound was first developed to address the issue of scanning the prostate and rectum. "Although we are critical of it, in large part the technique has been successful and remains the accepted standard due to the capability of ultrasound to easily resolve rectal wall layers. Also, a major part of the patient population is men, who would be staged utilizing transrectal ultrasound. We have tried to improve our ability of evaluating rectal neoplasms in women, and our results show that we've accomplished that by using transvaginal ultrasound," she said.
The researchers also found that transvaginal ultrasound was useful for other nongynecologic conditions. "Besides staging rectal tumors, transvaginal ultrasound has helped us diagnose other bowel pathology including gastrointestinal stromal tumors, inflammatory bowel disease, anorectal fistulas and fissures, and tumors and metastases in the rectovaginal pouch," said Stephanie Wilson, MD, supervising author of the study and head of the ultrasound division at the Toronto General Hospital.
The study will be presented on May 3 during the American Roentgen Ray Society Annual Meeting in Miami Beach, FL.