[Isodose curves for the tangential application to the breast]

The auxiliary collimating device furnished by Atomic Energy of Canada Ltd is constituted of a metalic base with a acrilic plate at the end and is fixed at the trimmer. This device is generally used in the irradiation of the breast in order to minimize the dose to the lung. Since only one isodose curve was furnished, the construction of others field sizes became necessary. Two systems of measurements were used. Isodose curves were obtained by decrement lines and scanning semi-conductor detector techniques. The problem associated to the measurements are also discussed.