A novel homogeneous irradiation fiber probe for whole bladder wall photodynamic therapy

Background and Objective We designed and fabricated a novel fiber probe that homogeneously illuminates the urinary bladder cavity for photodynamic therapy (PDT) of bladder cancer, which is known to occur in multifocal areas and to proliferate diffusely in the bladder mucosa. Study Design/Materials and Methods One end of a quartz multicore fiber was twisted and conically shaped, and the sharpened apex of the fiber end was rounded in order to provide light of which the fluence distribution approximates the three‐dimensional shape of the bladder cavity of rats. The superiority of the developed fiber probe (homogenous irradiation fiber probe: HIFiP) to a control fiber with a flat cleaved end (CF) in Photofrin®‐PDT using a rat orthotopic bladder cancer model was evaluated. Results Percentage of irradiated area to the whole area of the mucosal surface of the bladder was 36% in the case of the CF, while it was 69% in the case of HIFiP (P = 0.04). A greater PDT effect was seen in rats with HIFiP‐PDT, the volume of tumors (5.0 mm3) being less than half of that in the CF group (11.8 mm3; P = 0.02). Conclusions HIFiP succeeded in delivering light homogenously to a wide area of the bladder cavity, resulting in enhancement of the PDT effect on bladder cancer. Lasers Surg. Med. 44: 413–420, 2012. © 2012 Wiley Periodicals, Inc.