Why radiotherapy?
The aim of radiotherapy is to destroy tumour cells while sparing healthy tissue as much as possible.
Depending on the aim of the treatment, a distinction is made between curative and palliative
radiotherapy.
In curative radiotherapy, the aim is to cure the tumour disease if this is possible. In some cases, the use of radiotherapy alone is sufficient to achieve this. Other tumours respond better to combined therapy. A typical example of this is radiotherapy after an operation in which a tumour (visible to the naked eye) has been removed.
Any remaining individual tumour cells should be destroyed with the help of radiation during follow-up treatment. Depending on the tumour, this can be achieved by radiotherapy alone or by a combination of radiotherapy and chemotherapy.
The aim of palliative treatment is to alleviate or eliminate symptoms such as pain, restricted movement, urinary retention, difficulty swallowing or shortness of breath. The prevention of impending complications, e.g. bone fractures or paralyses, is also part of the palliative treatment objective.
In most cases, patients tolerate the treatment so well that it can be carried out on an outpatient basis. Only rarely is hospitalisation necessary.
What types of radiation are there?
Two types of radiation can be used for treatment:
- Ultra-hard X-rays (photons of higher energy), which are particularly suitable for treating deep-seated tumours.
- Electrons, which penetrate only a few centimetres into the tissue and are therefore very suitable for treating tumours close to the surface.
How can radiotherapy be used?
In most cases, radiation is delivered "externally", i.e. the radiation is produced with a special radiation device and directed through the skin ("percutaneously") onto the tumour located in the body.
The devices used to generate the radiation are known as linear accelerators. With the help of a linear accelerator, electrons are accelerated to almost the speed of light. The electrons emitted from the accelerator can then be used directly to treat superficial tumours. When treating deeper tumours, however, the energy of the electrons is first converted into X-rays (photons) by a physical process, as this type of radiation has a greater range in the tissue than electron radiation. In general, the penetration depth of a type of radiation increases with increasing energy.
The following types and energies of radiation are available at the Department of Radiotherapy and Radiation Oncology in Ulm:
- Photon radiation (6 MV, 10 MV and 15 MV)
- Electron radiation (6 MeV, 9 MeV, 12 MeV and 15 MeV)
How does radiotherapy work?
When these rays interact with the tumour tissue, the tumour cells can be damaged in such a way that they lose their ability to divide and slowly die off. The exact depth and area at which the radiation is effective is determined and calculated by the doctor together with the medical physicists.
Preparations for radiotherapy aim to ensure that the radiotherapy is as gentle and efficient as possible.
Fortunately, healthy cells are more capable of repair than tumour cells. Up to a certain dose, they rarely lose their ability to divide and can recover from the radiation within several hours. For this reason, the treatment is carried out in many individual sessions at intervals of several hours. A common schedule is daily irradiation from Monday to Friday with a break over the weekend.
What side effects can occur during radiotherapy?
Although we carry out the treatment as gently as possible, acute reactions cannot always be avoided. The extent depends on the size and localisation of the radiation field, the total and individual dose and the patient's general condition. During your consultation, the doctor will inform you about the possible symptoms.
A distinction is made between two types:
- Acute reactions
These symptoms, e.g. tiredness, slight nausea, loss of appetite or reddening of the skin, occur during treatment and subside soon after radiotherapy. They can be alleviated with medication.
- Late reactions
Changes in healthy irradiated tissue can develop months to years after treatment. Examples of this are skin discolouration or hardening of the subcutaneous fatty tissue. These changes usually persist. Thanks to the use of increasingly precise medical technology and many years of experience in radiotherapy, late effects are becoming increasingly rare.
In principle, we only carry out radiotherapy if the more favourable effect of the treatment far outweighs the possible adverse effects of the radiation.