A dose monitoring system in high dose rate intracavitary remote afterloading therapy of carcinoma of the uterine cervix using semi-conductor dosimeter.

Our intention was to develop a high accuracy procedure in high dose rate intracavitary remote afterloading therapy of carcinoma of the uterine cervix similar to the accurate dosimetry used in external irradiation. Semi-conductor in-vivo-dosimetry was carried out in order to determine the extent of errors in the calculated dose at reference points and in the definition of point A. The use of a rapid processing computerized system before the treatment was developed in order to decrease the difference between the dose delivered at point A dose and the planned dose. Errors in calculation of within +/- 10% seemed to be unavoidable in the hgh dose rate intracavitary afterloading therapy of carcinoma of the uterine cervix. Two definitions should be used in patients to compute the point A dose according to the ovoid position. Using the rapid processing system, wo could deliver a point A dose within +/- 5% level of the planned dose. The remotely controlled afterloader was safely operated by means of in-vivo-dosimetry which was backed up in routine clinical practice by a pretreatment calculated dose.