The word "metastasis" derives from the ancient Greek word "metástasis", which means "migration". In medical terms, this refers to the migration of malignant tumours to distant organs. About a quarter of all tumours in the body spread to the brain and thus form metastases.
Predestined for brain metastases are lung carcinomas, breast cancer, skin cancer and malignant tumours of the gastrointestinal and urogenital tract. As these types of tumours tend to occur at an advanced age, brain metastases are most likely to occur around the age of 60 - 80. In this age group they form the largest group of brain tumors.
Metastases can occur individually or in groups. As with all other masses in the brain, their growth causes problems since space inside the skull is limited.
A brain metastasis – as comparable to other brain tumours - can be responsible for a wide range of symptoms depending on its location. A growth in the forebrain can lead to changes in character, while in the area of the speech centers it can cause speech disorders (dysphasia, aphasia). In the case of a tumor in the motor center, paralysis often occurs. Epileptic seizures are also a frequent initial manifestation of a brain metastasis.
If the tumor spreads into the cerebellum balance difficulties, impaired movement coordination or dizziness may be developing.
In general, one or several brain metastases can lead to significant swelling, mass effect and increased intra-cranial pressure, which results in headache, nausea, vomiting, drowsiness or even loss of consciousness.
If a brain metastasis is discovered, the various disciplines treating the original tumour develop a joint treatment plan including neurosurgery and radiotherapy. Despite the progress made in chemo- and radiotherapy, surgical removal of the tumor, especially in the case of individual metastases with existing or impending symptoms, is of great importance.
If possible, metastases should always be removed in toto, which means to the full extent. Ideally, this is accomplished using the no-touch technique: the metastasis is microsurgically dissected with a safety margin without manipulating or opening it. In this way malignant cells are prevented from spreading into the surrounding tissue.
Often metastases can be easily separated from healthy brain tissue under the surgical microscope, which simplifies the implementation of the no-touch technique. If the tissue differentiation is difficult or if the metastases are deep, intra-operative ultrasound, intra-operative navigation and occasionally intra-operative MRI are employed to detect and resect the tumor precisely and entirely.
Successful tumor resection often leads to rapid relief of symptoms and improvement of quality of life. Interdisciplinary cooperation is of fundamental importance for further therapeutic success. Therefore we hold weekly interdisciplinary tumor boards in which all patients are regularly discussed. Occasionally we involve external international experts via video conference call. In this way different therapeutic aspects including surgical tumor resection, radiotherapy, chemotherapy as well as the therapy of the underlying primary tumor disease, form an individually tailored treatment concept – aiming to optimize outcome and prognosis.