A Radium Technic for Treatment of Cancer of the Cervix

Abstract

The rationale of radium application technics in cancer of the cervix is discussed. A method based on a modified Stockholm system is described, together with the dosimetry involved. Vaginal applicators consisting of a series of rubber cylinders cut to fit the size of tumor and vaginal apex deliver lower doses to the anterior rectal wall than ovoids and provide more flexibility than fixed colpostats. Emphasis is placed on covering the tumor surface and on keeping scintillation probe readings in bladder and rectum within safe limits. Studies show that the tandem contributes the major portion of the bladder dose, while the vaginal radium plaque contributes most of the rectal dose. Isodose curves based on measurements made in a water phantom are shown for intrauterine and vaginal applicators with standard loadings. Results with this technic have been satisfactory and injury rates low.