Evaluation of a new Fletcher applicator using Cesium-137

The improved Fletcher Applicator is a recent modification of the afterloading Fletcher system. Its aluminum construction reduces the weight by 50% and is more comfortable for the patient. Removable caps contain medially placed tungsten screens that shield tissues anteriorly and posteriorly. A method for evaluating the dosimetry of brachytherapy applicators in a water phantom was devised so this applicator could be studied and compared with other gynecologic applicators. The results show that the transmission ratios differ from those of the preloaded Fletcher colpostat, but are similar to the transmission ratios of the Fletcher-Suit applicator. There is a 10% to 25% reduction in the radiation dose to the region of the bladder trigone and anterior rectum with the shield containing cap in place