[Development of special electron applicators for intraoperative radiotherapy at the Grosshadern Clinic]

A specialized applicator system for intraoperative radiation therapy using high energy electrons of a linear accelerator has been developed and manufactured, regarding the specific situation that there is no dedicated linear accelerator available at the surgery facility. Additionally, long lasting interruptions of the daily routine irradiations are hardly tolerable. A significant improvement of the procedure could be achieved developing applicators, which are divided into two halves. Positioning the lower part of the applicator into the patient at the operating room already, the transportation and the irradiation of the closed patient is possible. Adapted to the linear accelerator in use, a Siemens Mevatron KD having electron energies in the range from 6 to 21 MeV, the dosimetric properties of the system have been optimized by iteration. Excess dose values near the applicator walls could be avoided completely. A rapid decrease of the leakage dose could be realized.