Brain tumours

All brain tumours (glioma) are a systemic disease of the brain. It is therefore a disease that extends beyond the volume shown on the image. Microscopically, the boundaries cannot be determined with certainty. As a result, these diseases are generally not curable by surgery alone and require a therapy concept that includes other options such as chemotherapy or radiotherapy. Non-brain tumours, such as metastases, are usually easier to differentiate from brain tissue.

In Germany, around 8,000 people are newly diagnosed with various brain tumours every year. Anaplastic astrocytoma (WHO grade III) and glioblastoma multiforme (WHO grade IV) are together the most common brain tumours with an increasing incidence. The occurrence of other tumours such as meningiomas, medulloblastomas and lymphomas is rarer, and there are many other types of brain tumours that occur very rarely. In principle, a brain tumour can develop at any age. However, people over the age of 40 are most frequently affected. Only medulloblastoma is the most common brain tumour in children from an early age.

The causes for the development of brain tumours have not been clarified. Despite thorough research, no clear triggering factors for the development of brain tumours have yet been found. Brain tumours can occur more frequently after previous cranial irradiation. There may also be a familial clustering of this disease. Certain genetic changes, such as Turcot syndrome, Li-Fraumeni syndrome or tuberous sclerosis, have been proven to contribute to the development of cancer. Various chemical noxae, such as vinyl chloride exposure and petrochemical substances, are being discussed as a cause for the development of these tumours. The influence of electromagnetic radiation (e.g. from high-voltage pylons and radio telephones) has not yet been proven.

The first symptoms of a brain tumour are usually uncharacteristic, e.g. tiredness and reduced physical performance. Around half of all patients often experience headaches first, especially at night and early in the morning. During the course of the day, the pain then subsides somewhat. Headaches caused by a brain tumour increase steadily within a few days or weeks and can hardly be suppressed by painkillers. The headache may also be accompanied by nausea and vomiting.

Other signs of a brain tumour can include paralysis, visual disturbances, sensory disturbances, speech and language disorders, coordination disorders and impaired reactions. An epileptic seizure occurring for the first time can be an indication of a possible tumour disease of the brain. Personality changes can also be an effect of a brain tumour.

If you are suspected of having a brain tumour, various examination procedures are necessary in order to make an accurate diagnosis. These include, for example, a physical examination and laboratory tests.

Computed tomography (CT) can already provide a groundbreaking diagnosis. Magnetic resonance imaging (MRI) is always necessary for a more precise diagnosis. Further technical examinations are required depending on the suspected diagnosis (skeletal scintigraphy, nuclear medicine (PET)).

If it is suspected that the change in the head is a metastasis of a tumour in another organ, appropriate examinations of this region of the body must be carried out

Medical history and physical examination

During a detailed consultation, you will tell the doctor about all your symptoms and previous illnesses (including family hereditary diseases). You will then undergo a thorough physical examination.

X-ray examination

The X-ray examination is used to detect a tumour in the lung area and/or to rule out lung metastases.

Sonography (ultrasound examination)

Sonography is a painless and radiation-free examination. It can detect the spread of a tumour to organs in the upper abdomen and/or existing metastases (tumour metastases), e.g. in the liver.

Computed tomography (CT)

Computed tomography is a special X-ray examination (with contrast medium) that scans the body layer by layer and can therefore show the exact location and size of the tumour. -> see also tumour-specific nuclear medicine diagnostics - PET(C11-methionine, F-18-FDG)

Magnetic resonance imaging (MRI)

MRI is not an X-ray examination, but is based on magnetic field effects. It may be necessary for the diagnosis of various tumours, including brain tumours.

Skeletal scintigraphy (bone scintigraphy)

By administering small amounts of radioactive substances into the bloodstream, tumour metastases in the bones can be visualised. A special camera recognises the radioactively enriched areas in the diseased bone. This is a gentle examination in which the radiation decays quickly.

Biopsies (tissue samples)

It is necessary to take a tissue sample in order to classify the type of tumour (tumour classification). At the same time, the degree of malignancy and special characteristics of the tumour can be examined in the tissue removed in order to be able to carry out targeted tumour therapy.

In order to be able to determine the most suitable therapy, it is necessary to determine exactly which histological subtype (tissue type) the brain tumour corresponds to, what degree of aggressiveness (according to WHO) it has and how far it has already spread. In other words, the tumour stage is determined. The WHO classification and the TNM classification are used for this purpose (see tables below).

Fine tissue subtype

Brain tumours are divided into different subtypes on the basis of histological examination: e.g. gliomas, medulloblastomas, meningiomas, lymphomas, etc.

Degree of aggressiveness of brain tumours (WHO classification)

The treatment methods depend on the tissue type of the tumour, the age and general condition of the patient and the size and location of the tumour in the brain. In principle, the earlier a brain tumour is detected, the more favourable the prognosis for the patient. However, depending on the WHO classification of the tumour, a cure is usually not possible, but rather symptom control, possibly with an extension of survival and stabilisation or reduction of the tumour size.

Three different treatment options can be used alone or in combination

Surgery

In the ideal case, which occurs very rarely, the brain tumour can be completely removed surgically without leaving any tumour cells behind. However, it is often only possible to remove a large part of the tumour. In some cases, e.g. if the patient is in a poor general condition or the tumour is in an unfavourable location, it may only be possible to take a small tissue sample (biopsy) to confirm the diagnosis.

Surgery followed by radiotherapy with/without chemotherapy

As in the vast majority of cases it is not possible to completely remove the tumour cells and extensive surgery would damage vital structures of the brain, follow-up treatment with radiotherapy and/or chemotherapy is recommended. Depending on the WHO grade of the tumour, follow-up treatment is also advisable even if the tumour has been completely removed

Radiotherapy as initial treatment

Radiotherapy as initial therapy is used in particular if the tumour is located at a particularly critical site in the brain and therefore only a biopsy is possible and not surgery. The number of radiotherapy sessions and the intensity of the radiotherapy depend on the type of tissue. During radiotherapy, side effects such as head pressure, headaches, nausea, hair loss and possibly fatigue may occur. However, most side effects can often be alleviated through the use of various medications.

How radiotherapy works

Like chemotherapy, radiotherapy aims to destroy the cancer cells. A targeted concentration of radiation is used to damage the cancer cells while sparing the healthy tissue.

As it is usually not possible to surgically remove tumours from the brain completely, the remaining tumour cells are destroyed by radiotherapy following surgical tumour removal or biopsy. This is intended to prevent renewed local tumour growth or further tumour spread with recurrence of symptoms. For this reason, surgery for brain tumours is usually followed by radiotherapy, which can often be carried out on an outpatient basis.

Radiotherapy can reduce the risk of the tumour growing again. Radiotherapy can also be used for advanced tumour diseases with large tumours or metastases, in this case in particular to control symptoms and relieve pain.

Chemotherapy

Chemotherapy alone, without surgery and radiotherapy, has little effect on most brain tumours. However, when used in combination with radiotherapy, chemotherapy can improve the effect of radiotherapy. Chemotherapy can be continued after the end of radiotherapy if it is proven to be effective in order to maintain and further improve the effect achieved up to that point (symptom control, size stabilisation or size reduction). Even when chemotherapy is used after radiotherapy, if this is no longer possible, e.g. in the event of a recurrence of a tumour, various substances and various combinations can be used to achieve symptom control, possibly with a response of the tumour (size stabilisation or size reduction).

Newer, well-tolerated substances have recently become available for the chemotherapy of brain tumours, for which efficacy has been demonstrated in various brain tumours and still needs to be demonstrated for other tumours. As the effectiveness of many known and newly developed substances in the treatment of brain tumours is being investigated on the basis of new findings, it is generally advisable for patients with a brain tumour to have these tumour-specific therapies carried out by specialist doctors at "therapy centres" and, if possible, within "clinical trials". Some of these therapies can be carried out on an outpatient basis.

Some tumours are treated differently from the above: In children with medulloblastoma, chemotherapy is carried out up to the age of 4 after surgery, as radiation exposure would be too great for the child's brain.

In the case of lymphoma, chemotherapy is used followed by radiotherapy only in individual cases, depending on the response, in order to achieve a more effective effect.

Here too, the therapy is carried out within the framework of a strictly defined protocol.

If the tumour recurs, all the treatment options already used must be considered again: Surgery, radiotherapy and chemotherapy.

It is not possible to make a general statement as to which therapy is suitable.

The therapy concept is determined by the treating clinics in agreement. Specific and regular conferences are planned for this purpose (tumour board).

In the case of brain tumours (gliomas), metastases to other organ systems only occur in extremely rare cases. Exceptions are ependymomas, which originate from cells lining the cerebrospinal fluid spaces. Here, metastases can occur in the cerebrospinal fluid space. Accordingly, magnetic resonance imaging examinations of the entire spinal column are carried out.

As a rule, local recurrences must therefore be treated.

Imaging examinations are carried out depending on the aggressiveness of the tumour. Usually at intervals of at least 3 to 6 months. If a change in therapy is necessary, more often. Magnetic resonance imaging is usually the best method. If chemotherapy is carried out, the blood count must be monitored.

Rehabilitation is possible on an outpatient or inpatient basis if neurological disorders occur.

The aim of the therapy is to enable the patient to lead a normal life. The patient should already be integrated into everyday life during therapy, as long as it does not require hospitalisation as in the case of surgery.

The prognosis depends on the primary diagnosis: the tissue examination (neuropathology), spread and localisation determine the therapy and therefore also the further course of the disease. Increasingly, molecular genetic examinations can influence the therapy. The aim is to determine an individualised therapy for the patient and thus to achieve recurrence-free survival for as many years as possible or, in the event of recurrence, to enable rapid and effective treatment. A definitive cure cannot (yet) be achieved for aggressive gliomas.

Metastases and other non-brain tumours can often be completely and permanently removed.