The provision of a uniform vaginal surface dose rate by a novel afterloading cylinder

The administration of a uniform dose rate to the vaginal surface is important in the management of endometrial, cervical, and vaginal malignancies. Unfortunately, conventional vaginal cylinders fail to provide this uniformity, and although dome cylinders do so, they require specialized 137Cs sources. Thus, a new acrylic vaginal cylinder has been developed to use with standard 137Cs sources and provides a uniform dose rate independent of vaginal size. Each contoured cylinder follows a particular isodose line. A metal ring is used to secure the device to minimize vulvar trauma associated with other vaginal cylinders. The construction and use of a set of these cylinders has allowed determination of their utility and limitations, which will be discussed in detail. Although these applicators do not completely replace conventional cylinders, they do offer a useful addition to the brachy-therapeutic armamentarium.