Intrauterine light probe for photodynamic ablation therapy

Background: Endometrial ablation by means of photodynamic therapy is curren tly being evaluated as an outpatient treatment for dysfunctional uterine bl eeding. Photodynamic therapy requires the activation of a photosensitizer b y laser light. We describe a new device specifically designed to provide li ght delivery to the uterus for endometrial photodynamic therapy. Instrument: The intrauterine light probe consists of the three flexible opt ical fibers converging to one bundle resembling the shape of the uterine ca vity. Each of the fibers contains a cylindrical light diffuser. Experience: The intrauterine light probe was tested in removed human uteri for its capability to distribute light in a tissue-simulating scattering me dium and to deliver sufficient light throughout the endometrium. The light distribution of the intrauterine light probe in the scattering medium is un iform on eight axes tested around the diffusing fibers. The pattern of ligh t distribution in human uteri is similar to that in the medium. At the endo myometrial junction, there is still one third of the light applied to the e ndometrial surface whereas deeper in the myometrium, the light power drops to less than 10%. Conclusion: We propose a device that will deliver light to the uterine cavi ty to induce endometrial ablation by means of photodynamic therapy. (Obstet Gynecol 1999;93:299-303. (C) 1999 by The American College of Obstetricians and Gynecologists.).