Mayo Clinic News

Making tumors inside the bladder fluoresce red under blue light allows physicians to more easily find and remove them, substantially reducing the rate at which these cancers come back, says Lance Mynderse, M.D., Mayo Clinic urologist who is presenting results of a large, multicenter international clinical trial.

The findings, which are being reported at the annual meeting of the American Urological Association, show that this new diagnostic technique found more of the most common bladder tumors than the traditional white-light detection method in almost 17 percent of the patients, and demonstrated a 22 percent relative reduction in the recurrence rate within nine months of the procedure.

The study compared use of the traditional white-light cystoscopy with photodynamic diagnosis using a special light source and lenses that can switch from white to blue light. The blue light is designed for use with the study drug (hexaminolevulinate), which is instilled into a patient’s bladder prior to the therapeutic procedure. This acts as a prodrug that initiates a series of biochemical reactions in malignant cells which result in significant, preferential accumulation of photoactive porphryins. When the blue light is turned on, the tumors emit a red fluorescence. “The cancers appear bright red compared to normal tissue, which is a lighter blue-green,” Dr. Mynderse says. “It is quite dramatic. One sees bladder tumors in a whole new light.”
 
Below is a link to an edited youtube video with Dr. Mynderse .