Radiotherapy

Author:  Dr. med. habil. Gesche Tallen, Editor:  Maria Yiallouros, Reviewer:  Prof. Dr. med. Dr. h.c. Günter Henze, English Translation:  Hannah McRae, Last modification: 2020/06/18 https://kinderkrebsinfo.de/doi/e221020

Over 100 years ago, in 1895, the researcher Wilhelm Conrad Röntgen discovered a type of radiation (X-rays or ionising radiation), by which it was possible to see through solid objects and living organisms. This revolutionary observation was named after its discoverer and has many different applications in the diagnosis and treatment of cancer today.

The biological effects of X-rays (and other forms of ionising radiation) have been carefully examined through decades of research. We know the potential of their positive uses as well as the unwanted side effects they can cause. In the course of technological development, the equipment and forms of radiation used in radiation therapy have been improved in many ways, so that many serious side effects can be avoided today.

In principle, different forms of cancer treatment (such as surgery, chemotherapy, and radiation) are combined with each other so that the side effects of each can be minimised. For example, radiation following surgery and/or chemotherapy to shrink a tumour sometimes allows for a lower dose of radiation with a smaller irradiation field to be used than a treatment with radiation alone.

Radiation may have the following objectives in paediatric oncology:

• Complete elimination of localised solid tumours that are hard to access by surgery due to their anatomical location and/or are not sensitive to chemotherapy. The stage of the disease should be early and no metastases should have formed in order to make this approach successful. If possible, complete eradication of both a tumour and adjacent lymph node metastases by radiation alone (monotherapy) can be persued.
• Complete tumour elimination by combining radiotherapy with either pre- or post-radiation surgery and/or chemotherapy (combination therapy); radiotherapy which is performed prior to other treatments is called “neoadjuvant”, whereas radiation following other treatments is named “adjuvant”. A simultaneous therapy is possible, too.
• Improve the prognosis in patients who still have a high risk of relapse after the tumour's removal by surgery and/or chemotherapy (adjuvant radiation)

The complete elimination of cancer cells can be either persued by radiation alone or by combining radiation (simultaneously, neoadjuvantly or adjuvantly) with other treatment methods like surgery and/or chemotherapy. Overall, children and adolescents with cancer have an 80 % chance of cure today [KAA2019‎].

For some patients, however, treatment options are limited to delaying the progression of the disease and to alleviate disease-related symptoms (palliative therapy).