MDCT urography is a promising technique for detecting bladder tumors both with and without contrast material, helping patients avoid an invasive test, according to a new study by researchers from the University of Michigan Health System in Ann Arbor, MI.
For the study, 92 patients with bladder cancers were evaluated with MDCT. The researchers were able to identify 87 of the 92 bladder tumors on MDCT, regardless of whether the portion of the bladder was opacified with contrast material or not. Usually, bladder cancer is detected by cystoscopy, an uncomfortable procedure in which an instrument is inserted into the urethra to sample or see inside the bladder. "Urologists often ask for MDCT to evaluate the ureters and kidneys for further disease. In doing so, we found that we saw most of the bladder cancers identified by cystoscopy on our MDCT, so we wondered if MDCT could be used to investigate the bladder on its own. Based on our study, it looks like this is a possibility," said Jonathan Willatt, MD, lead author of the study.
In addition, the researchers found that it didn't always matter whether contrast was used or not. "The problem with contrast material is that once it has passed from the ureters to the bladder it tends to opacify unevenly. When this happens, the doctors either roll the patient over repeatedly to mix the urine and contrast or administer a diuretic to get the patient to void and then allow the bladder to fill with contrast-enhanced urine. We found that we could see almost all of our tumors in the unopacified part," said Dr. Willatt. "With new CT technology we can scan so rapidly that if we time it right, and if we get the bladder full enough, we feel that there is scope for evaluating the bladder fully with CT which may obviate the need for the more invasive and less comfortable cystoscopy," he added.
The researchers also discovered that both CT and cystoscopy struggle with patients who have had previous bladder treatment such as surgery, radiotherapy or chemotherapy, so monitoring cancer recurrence is still a problem for both tests.
The full results of the study were presented on Monday, May 1, 2006 during the American Roentgen Ray Society Annual Meeting in Vancouver, BC.