Bladder cancer is the fourth leading cause of cancer death in males and the most common site of cancer in the urinary system. An estimated 74,000 new cases of bladder cancer are expected to be diagnosed in the USA in 2015 and 16,000 deaths are estimated. Non-muscle-invasive bladder cancer (NMIBC) has a high rate of recurrence and also a risk of progression that requires patients to undergo regular monitoring with cystoscopy after transurethral resection of the bladder tumor (TURBT). Current standard of care uses white-light cystoscopy (WLC) to map and resect all visible tumors. This blog will give an overview of the use of fluorescent cystoscopy in the management of NMIBC and review the evidence for its use.
Blue-light cystoscopy (BLC), also referred to as fluorescent cystoscopy or photodynamic diagnosis (PDD), is a procedure in which a photosensitizer medication is instilled in the bladder prior to cystoscopy. This photosensitizer is part of the heme biosynthesis pathway (that makes red blood cells) and causes an accumulation of photoactive porphyrins in neoplastic cells. These porphyrins preferentially accumulate in neoplastic cells due to the increased metabolic activity in these cells. When excited with blue-light in the 360-450 nm wavelength, the porphyrins emit a red light that can easily be seen during cystoscopy (Figure 1). There are two main photosensitizers that have been used in studies looking at fluorescent cystoscopy: 5-aminolevulinic acid (5-ALA) and hexaminolevulinate (HAL). HAL is the only photosensitizer that has been approved for use in the USA and Europe. In the USA it is marketed under the brand name Cysview, and in Europe under the brand name Hexvix.