VI./4.5.: Therapy

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Non-specific, supportive treatment of brain metastases and primary tumors are not different. Vasogenic, perifocal oedema is treated with corticosteroids (e.g. parenteral dexamethasone or oral methylprednisolon). Since great majority of the symptoms may be caused by brain swelling, decrease in severity of symptoms and complaints may be expected at first. Additionally, loop diuretics, or in more severe cases glycerine or mannitol can be used if the intracranial pressure is increased. Symptomatic epileptic seizure needs antiepileptic treatment. Prophylactic antiepileptic medication is often given by neurosurgeons due to the increased risk of seizures in the preoperative stage; but the routine prophylactic use is not recommended.

Complex treatment strategy is established by the oncologist, specialist of the primary tumor’s location, neurosurgeon and radiologist.

The specific treatment method of the brain metastasis depends on the multiplicity of the lesion, the severity of the symptoms, but also on the oncologic stage, systemic dissemination, histology and response to systemic treatments of the primary cancer. Surgery is indicated if the life expectancy with acceptable quality of life is at least 4-6 months after the operation.

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Open craniotomy and excision is recommended in case of solitary, at least 3 cm large lesion located in non-eloquent area of the brain. The primary tumor should be known and controlled in ideal case. Karnofsky score should be at least 70, which means that the patient is able to walk alone, look after himself and do light physical activity. (Karnofsky score is an international scoring system of 0-100%, describing general condition regardless of disease). In case of one large and several smaller metastatic lesions, the previous could be operated while the smaller metastases are treated with e.g. radiosurgery.

Some of the previously inaccessible (deep, basal, multiple) brain metastases became manageable with radiosurgical methods. This gamma-knife focuses high intensity (20-25 Gy) gamma-radiation in the center of the lesion without damaging the adjacent healthy brain tissue. Months needed to the gradual decrease in size of the treated lesion, followed by MRI. Usually max four metastases could be treated that way, if their sizes are smaller then 3 cm (8).

Whole Brain Radiation Therapy (WBRT) might be the only choice in patients with multiple brain manifestation or recurrent tumors, or in case of generally severe condition (10). The effect of the treatment is highly influenced by the radiosensitivity of the cancer: e.g. small cell lung cancer and germ cell tumors respond better then malignant melanomas and renal tumors (9). Complication of the WBRT may be encephalopathy leading to dementia because of the extensive cerebral, white matter radiation necrosis. The complex treatment strategy is individual; radiotherapy can be combined with both operation and radiosurgery with the similar overall effectiveness.

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Treatment of brain metastases with chemotherapy is generally ineffective even if the primary cancer is responding. The failure of the chemotherapy is explained by the function of the blood-brain-barrier. Metastatic breast cancer responded to temozolomide treatment (lipid-solvent agent), and e.g. fotemustine is tried in variety of metastatic brain tumors. Chemotherapy and whole brain radiation therapy in combination may also be an optional treatment strategy.

Regular follow-up visits, monitoring neuroimaging and laboratory findings; checking for and treating the side-effects of the treatment (e.g. polyneuropathy, radiation necrosis, general complaints) are important. The complex treatment needs cooperating doctors and team working in different fields.

Last modified: Sunday, 25 August 2013, 11:09 AM