Use of computed tomography for the fabrication of a custom brachytherapy carrier: A clinical report

Early methods of fabricating customized radiation carriers for inaccessible areas, such as the nasopharyngeal space, normally required the patient to be under conscious sedation or general anesthesia to allow impressions for indirect processing techniques. This article describes the use of computed tomography to design and fabricate a carrier for the intracavity application of iodine 125 seeds for a patient with rhabdomyosarcoma of the nasopharynx. With tomography printed copies, a wax pattern was formed, flasked, boiled out, and eventually replaced with silicone material. The patient had to be available only for a conventional thin-cut computed tomography scan without contrast; no fitting appointments or anesthesia were necessary. The indirect procedure eliminated discomfort from impression making and allowed for precise fabrication of the nasopharyngeal carrier. The described technique can be used for other intracavitary radiation applications.