[Emergency rescue in accidents with HDR afterloading units]

HDR brachyradiotherapy has minimized the exposure to radiation of the personnel working in this field. Nonetheless there are periodically reported troubles with afterloading units concerning the retraction of sources that require immediate action for the limitation of possible damage. LEGAL PRINCIPLES ACCORDING TO THE GERMAN REGULATION CONCERNING PROTECTION AGAINST RADIATION (STRAHLENSCHUTZVERORDNUNG = STRLSCHV): If in afterloading brachyradiotherapy the radiation source remains extended through malfunction we deal with an emergency according to the StrlSchV. The rescue personnel should be chosen in accordance with section 50 StrlSchV (Table 1).

The quickest possible rescue of a patient in an emergency demands an unequivocal definition of responsibilities. Our recommendations in this instance: the physicist is responsible for the organization of the emergency rescue. The radiation oncologist in charge informs himself about the necessary emergency measures before starting the treatment and carries out the emergency rescue. If the physicist diagnoses a failure in the retraction of the source he tries to remove the failure. If he doesn't succeed in retracting the source the radiation oncologist carries out the rescue of the patient. The organizational structure of the clinic allowing, the emergency physician should invariably be the physician who placed the applicator. In the emergency rescue the radiation oncologist should be protected by a lead barrier (Figure 1, Table 2) and use manipulators (Figure 1).

The radiation exposure of the rescue personnel is calculated from the photon-equivalence dose HX with the help of the dose-rate constant of 192Ir (Table 3). According to the same procedure there can be evaluated the local radiation exposure of the patient concerned (Table 3).

Generally speaking, all considerations regarding the topic of emergency rescue should always start out from a worst-case scenario. Of all the people involved the patient is the one who is most exposed if the radiation source is located inside his or her body. If an emergency rescue is necessary the radiation exposure of patient and personnel can only be minimized by a quick rescue. This end requires a properly equipped emergency workplace, good training of all the people concerned, and regular exercises of the rescue procedures. A well-practiced emergency management can be of life-saving importance for the patient.