[Irradiation technic, documentation and individual dosimetry in intracavitary short-term afterloading therapy].

Abstract

The different techniques and radioisotopes for the intracavitary remote-controlled afterloading therapy of the carcinoma of the cervix are discussed. Single or multi-channel applicators including sector-shielding are characterized. A modified 3-channel-applicator offers beside the well known advantages, the possibility to irradiate a vaginal infiltration and the cervix simultaneously and guarantees a definite distance to rectum and bladder and allows an improved representation on localisation-films. Extended tumor-invasion requires beside the intracavitary therapy an additional percutaneous irradiation. Depending on the theoretical approach, intracavitary or percutaneous therapy is predominant. The complex 3-dimensional intracavitary isodose distribution and the locally different fractionation has to be considered by matching the intracavitary and percutaneous therapy. The biological effect of different fractionations arising from the abrupt intracavitary isodose decrease, enlarged penumbra regions behind wedge-filters or slow decreasing isodoses from moving-field irradiations have to be taken into consideration.