Transillumination for accurate placement of radioactive plaques in brachytherapy of choroidal melanoma

Abstract

Purpose: To present a technique for accurate plaque placement in episcleral brachytherapy of choroidal melanoma.

Methods: The tumor margins are marked on the scleral surface, and a dummy plaque is temporarily sutured to the globe. A fiber optic light pipe is then wedged into the space between the sclera and the plaque. Because of the reflecting inner surface of the plaque, the perimeter of the plaque can easily be observed during indirect ophthalmoscopy as a circle of light surrounding the tumor. By this method, it is possible to determine the exact position of the entire plaque in relation to the tumor and make the necessary adjustments. When the correct position is found, the dummy plaque is replaced by a radioactive plaque.

Results: Since 1993, we have routinely used this procedure in episcleral brachytherapy.

Conclusion: This modified transillumination technique facilitates a correct positioning of episcleral plaques.