Preparation and implementation of radiation therapy

Author:  Dr. med. Gesche Riabowol (geb. Tallen), Editor:  Maria Yiallouros, English Translation:  Dr. med. Gesche Riabowol (geb. Tallen), Last modification: 2025/11/26 https://kinderkrebsinfo.de/doi/e211413

Prior to the first radiation‎ treatment, important preliminary examinations are required to carefully plan this therapy. The more precise the planning, the more targeted the radiation of the tumour can be and the gentler its effect on healthy adjacent organs.

Preliminary examinations as part of radiation planning include imaging‎ procedures, in particular X-ray examination‎s and computed tomography‎ (CT), sometimes also magnetic resonance imaging‎ (MRI). All the information that the radiation team receives about the tumour and the surrounding tissue is forwarded to a three-dimensionally supported planning computer using a special computer program. The radiation therapists use this to determine the region to be irradiated and physicists calculate the size and number (in the case of teletherapy) of the radiation fields. In this way, the treatment can first be simulated, i.e. theoretically played through on the computer.

As a rule, several radiation fields are chosen in classical radiation therapy from the outside (teletherapy) in order not to burden the skin or the neighboring organs too much with radiation [TIM2010‎]. In the context of teletherapy, which also includes stereotactic therapy, the radiation fields are then marked with a waterproof marker or with henna on the patient's skin.

Important: The skin markings should not be washed off until the entire radiation therapy has ended. Otherwise, the complex simulation will have to be carried out again.