Ultrasonics in radiotherapy: the planning of treatment and follow-up of its results

Ultrasonography is of great value in radiotherapy for treatment planning and for the follow up of the treatment results, because the extent of the tumor and its position to the adjacent organs can be visualized directly by cross sections. If photographs of the B-scan are superimposed by isidose curves, individualized treatment planning is possible. This is demonstrated in a few examples: the pre-operative irradiation of a Wilms tumor (Fig. 1), the irradiation of large aortic masses which require 3 treatment ports (Fig. 2) while for a smaller aortic mass moving beam therapy is suitable (Fig. 3). Examples for the follow up of the treatment results are given in Figs. 4–6. Figure 4 demonstrates the reduction of the tumor size corresponding to the different irradiation methods. The lack of radiosensitivity of certain tumors can be documented earlier by ultrasound than by other investigations. This enables the radiotherapist to change his treatment schedule in time (Fig. 6).