A brain tumor is usually a newly formed local mass of growing tissue in the brain. Brain tumors develop either directly from cells of the brain or as metastases from other tumors.
Brain tumors are classified according to criteria such as cellular origin, growth rate, or prognosis.
The origin and molecular properties of the cells are important for the classification of brain tumors. Does the tumor consist of the brain's own cells? Then it is a primary brain tumor that originated directly in the brain. If the tumor cells come from another organ, it is a secondary brain tumor, a so-called brain metastasis.
Brain metastases are secondaries tumors of a main tumor from another part of the body. The tumor from another organ is the primary tumor. Tumor cells can reach other parts of the body via the bloodstream or lymphatic system and place "offshoots" there, known as metastases. Tumors that frequently metastasize to the brain are lung tumors, breast cancer and black skin cancer (melanoma).
- Benign, intermediate and malignant brain tumors
Brain tumors can be divided into benign, intermediate (benign tumors with potential degeneration) or malignant brain tumors based on their growth behavior. Basic characteristics of a benign brain tumor are its slower growth rate and its clear differentiation from healthy tissue. However, the classification is not always easy, because there are also slow-growing tumors that grow in a very infiltrative manner, and initially benign tumors that degenerate into malignant brain tumors
- The WHO classification of brain tumors
The World Health Organization has classified primary brain tumors into four different WHO grades. The classification according to the WHO criteria, the molecular markers as well as the type of tumor cells are decisive for the further treatment of the tumor.
- WHO grade I corresponds to a benign, slow-growing brain tumor with a favorable prognosis
- WHO grade II corresponds to a rather benign to intermediate brain tumor
- WHO grade III corresponds to a rather malignant, rarely intermediate brain tumor
- WHO grade IV corresponds to a malignant brain tumor
Depending on the brain region affected, brain tumors can cause very different symptoms. Early detection is therefore often difficult. A brain tumor can manifest itself dramatically in an epileptic seizure or cause only very unspecific symptoms, which also frequently occur in harmless diseases. The localization of the tumor in the brain is decisive for the symptoms. Possible symptoms of brain tumors are:
Epileptic activity, i.e. hyperexcitability of the healthy tissue at the edge of the tumor.
- Failures or malfunctions
Impairment of speech, motor skills, sensation, vision, calculation, thinking, memory, balance, orientation, mood, behavior, alertness, drive, social behavior, etc. due to the pressure of the tumor on the surrounding tissue or the ingrowth into the adjacent brain.
- Headache, nausea, vomiting
An advanced tumor leads to an increase in intracranial pressure.
- Psychological changes
If the tumor grows in functionally silent (non-eloquent) parts of the brain, it may go unnoticed for some time until nonspecific symptoms such as change of character, fatigue, forgetfulness, disorientation and confusion appear. In most cases, the symptoms last from a few weeks to a few months at the time of diagnosis.
A brain tumor is diagnosed with the help of magnetic resonance imaging (MRI). It provides images of brain tissue. Using different filters (sequences), the various features of the tumor can be visualized. Depending on the type of tumor, findings range from an almost certain diagnosis, where surgery is usually the next step, to a vague suspected diagnosis that first requires a biopsy (tissue examination) to obtain a definitive diagnosis. Unfortunately, early detection through a blood test or screening examination does not yet exist.
At Inselspital, the best possible treatment strategy is determined individually for each patient. This is done in the certified Brain Tumor Center, where an interdisciplinary team discusses and determines all treatment options individually for each patient.
This weekly tumor board is composed of specialists from neurosurgery, neurology, neuro-oncology, nuclear medicine, radio-oncology as well as pathology.
Brain Tumor Center
Further treatment differs depending on the tumor. More detailed information on the therapy options can be found at the individual brain tumors.
The operation has two goals:
- If possible, the brain tumor should be completely removed down to the last cell.
- The normal functions of the brain should not be affected.
A benign brain tumor is cured after complete removal. In the case of a malignant brain tumor, such as a glioblastoma, complete tumor removal results in a better prognosis and survival time. At Inselspital, we use the latest methods in navigation, ultrasound, intraoperative MRI and fluorescence techniques, as well as state-of-the-art equipment to detect the tumor boundary during surgery.
However, the absolute priority before complete tumor removal is the preservation of brain functions to allow the patient to continue living a normal life in good quality. In both benign and malignant brain tumors, we would rather accept a tumor remnant than permanently damage an important brain function. In the case of benign tumors, this tumor remnant is often observed for years or is followed up and stopped by radiosurgery. In the case of malignant brain tumors that grow infiltratively and for which no complete cure is possible by surgery, radiation and chemotherapy will attack the residual tumor.
Neurosurgery at Inselspital is a leader in the field of surgical safety. To minimize the risk of permanent neurological disorders, important functions of the brain are constantly monitored during surgery. The type of monitoring is determined individually for each patient. This includes, for example
- Dynamic mapping which has been developed at our clinic and allows for the first time continuous localization of movement areas
- Awake operations to monitor speech comprehension or visual function
- Intraoperative monitoring which is not only a clinical focus and active field of research, but also a flagship of our clinic
Most brain tumor patients can be discharged home 5–7 days after their surgery. An appointment may be made in the following week to discuss the laboratory results (histology of the removed tumor tissue).
If neurological deficits such as speech or movement disorders occur postoperatively, inpatient neurological rehabilitation can be helpful. For this purpose, there are numerous specialized rehabilitation clinics in the region of Bern and the surrounding area. An application is made by the attending physicians at Inselspital, taking into account the individual patient's wishes.
If the patient suffers only from mild impairments or if inpatient rehabilitation is not desired, there are numerous outpatient therapy options to facilitate the return to familiar everyday life. These include outpatient physiotherapy, occupational therapy, speech therapy, psychosocial support, etc.
For benign and some intermediate tumors that do not require follow-up treatment, regular follow-up visits and MRI examinations are performed in the Neurosurgical Outpatient Clinic. The intervals for these check-ups depend on the type of tumor as well as the recommendation of our interdisciplinary tumor board.
In order to prevent the recurrence of a tumor after complete surgical removal or the growth of a tumor remnant, it may be useful to administer supplementary or supportive (adjuvant) chemotherapy, depending on the molecular characteristics and grading of the tumor. Chemotherapeutic agents are substances that exert a DNA-damaging effect in the tumor cells. For high-grade brain tumors (gliomas), postoperative chemotherapy with Temodal (temozolomide) is usually given in combination with radiation treatment. Temodal can usually be taken as a capsule and is actually well tolerated by patients.
Radiation therapy or radiotherapy is another important adjuvant (supportive) treatment after brain tumor surgery of higher-grade tumors. The aim is to stop the growth of remaining tumor cells. In this process, physically high-energy X-rays are produced by a linear accelerator and applied with high precision to the region of the brain tumor. The anatomical structures and surrounding brain territories are taken into account. As with chemotherapy, radiation therapy can disrupt the cell division process of tumor cells, leading to cancer cell death. To achieve the highest possible effect with the fewest possible side effects at the same time, hypofractionated (low-dose) radiotherapy is usually administered over several sessions. For high-grade gliomas, this corresponds to 30 sessions of 2 Gy each, or a total dose of 60 Gy.
Radiosurgery is a highly focused, high-dose, one- to five-times radiation treatment offered as a treatment alternative to open surgery for small, well-defined tumors. At Inselspital, a device of the latest generation, the so-called CyberKnife, is used for this purpose. With the help of a computer-controlled robotic arm, the high dose of radiation is administered with razor-sharp precision.
Infiltrating malignant or intermediate tumors often require additional treatment after surgery. However, the normal chemotherapeutic agents are not always effective enough. Doctors around the world are therefore constantly searching for new therapies, including completely new approaches, in order to achieve a breakthrough in the fight against malignant brain tumors. The success of these new therapeutic approaches must be verified and confirmed in strictly monitored and officially approved studies. We help our patients find a study that is appropriate for their disease.