Caesium manual afterloading intracavitary treatment of carcinoma cervix: A simple method of dose calculation

For the proper use of the computer calculated dose rate tables of Mould and Hobday for the Amersham 137Cs manual afterloading system with +-10% accuracy, a standard application should be employed. Using anteroposterior and lateral X-ray films of the pelvis, certain guidelines have been developed to describe such a standard application. Seventy-eight patients with carcinoma cervix were treated with the Amersham 137Cs manual afterloading system. In 9 instances there was disagreement between the ready-made dose rate tables and the two-dimensional detailed calculations. In 5 of these 9 cases the disagreement was due to non-standard application. In the remaining 4 cases the reasons were not clear. In all stage I cases (10 patients) no single local recurrence could be detected during a mean observation time of 20 months. Grade III or IV rectal or bladder reactions were not observed. Thus, this simple method of dose calculation could be used in developing countries for standard applications and when a trained medical physicist is not available. (author)