Curative radiotherapy

Author:  Dr. med. Gesche Riabowol (geb. Tallen), English Translation:  Dr. med. Gesche Riabowol (geb. Tallen), Last modification: 2026/01/12 https://kinderkrebsinfo.de/doi/e211241

Curative treatment concepts have the goal of curing the patient of his disease and preventing a relapse of the disease, i.e. to completely and permanently destroy all malignant cells. Radiotherapy can contribute to this in different ways, depending on the time and technique of its application and its focus.

Radiotherapy before surgery

Radiotherapy prior to surgery‎ is also known as preoperative‎ or neoadjuvant‎ radiotherapy. In some patients with large solid tumour‎s, such pre-radiation, often in combination with chemotherapy‎, can improve the success of the overall treatment. With the help of radiation therapy prior to surgery, it can be achieved that a tumour that is inoperable or difficult to operate on at the time of diagnosis (due to its size and site), shrinks so that it can be removed without increased risk to damage adjacent tissue.

Radiotherapy after surgery

Radiation therapy after surgery is called postoperative‎ or adjuvant‎ radiotherapy. In many children and adolescents with solid tumour‎s, especially tumours of the central nervous system‎ (CNS tumour‎s), radiation therapy is carried out in addition to chemotherapy (so-called chemoradiotherapy) after surgical tumour removal. This so-called chemoradiotherapy is applied, in particular, if the tumour could not be completely removed, for example due to its proximity to healthy adjacent or-gans/tissue and subsequent the risk of damaging them during surgery. The aim of radiation‎ in these patients is to completely destroy the remaining tumour tissue.

However, radiation after surgery can also be used to prevent relapses of the dise-ase. This means that the former tumour region is re-irradiated if there are potenti-ally remaining malignant cells due to certain histological‎ and molecular biological‎ properties of the tumour. In this case, follow-up radiation is also performed if the surgeon no longer sees a residual tumour macroscopically or if postoperative imaging diagnostics do not indicate a residual tumour.

This is particularly common in patients with medulloblastoma‎, the most common malignant CNS tumour‎ in children and adolescents. If they have reached a certain age (usually 3–5 years), they receive radiation of the brain‎ and spinal cord‎ (craniospinal radiation) and additional radiation of the tumour region (so-called boost), even after a complete tumour removal and in addition to chemotherapy. This way, tumour cells that may have remained in the brain and may have travelled into the spinal canal ("drip metastases") can be destroyed (see chapter "Indications") [TIM2018a‎].

Important: The brain of very young children (under 3–5 years of age) is particularly sensitive to radiation, because its tissue development is far from completely developed. Accordingly, the risk for these patients of later suffering from radiation-related functional impairments of the brain, intellectual disability and developmental disorders is greater than in older children. Therefore, younger children usually do not receive radiation therapy in the area of the central nervous system (CNS).

Radiotherapy alone (without surgery)

In certain situations, children and adolescents with blood cancer (leukaemia‎s) or with lymphoma‎s also receive radiation therapy of the brain in addition to chemotherapy, such as when cancer cells have been found in the cerebrovascular fluid‎ (CSF), since those cannot always be sufficiently destroyed by chemotherapy alone. Radiation, which is usually combined with cytostatic drug administration into the spinal canal (intrathecal chemotherapy‎), is intended to safely eliminate these cells.

Likewise, some patients with certain solid tumours do not undergo surgery, but receive either radiation therapy alone or a combination of chemotherapy and radiation therapy (chemoradiotherapy). These patients include, for example, children and adolescents with small retinoblastoma‎s for whom an eyeball-preserving treatment strategy can be used, as well as patients with certain tumours in the brainstem‎ (highly malignant glioma‎s) who cannot be operated on due to their location (see chapter "Indications").