Inclusion Criteria:

• Histologically or cytologically confirmed extracranial primary malignancy other than small cell lung cancer, germ cell tumor and lymphoma. Histological confirmation may have been from the primary tumor site, from another metastatic site, or from the metastatic brain lesion(s)
• 4-10 brain metastases, which are radiologically proven by MRI scan. The size of each metastasis must be between 3 mm and 4.0 cm in the largest diameter. Contrast-enhancements on MRI which are smaller than 3 mm in diameter are not considered. The total volume of the lesions must be smaller than 35 ml and the volume of perilesional normal brain receiving more than 4 Gy per fraction must be smaller than 40 ml. An evaluation of the latter criterion is strongly recommended for total lesions volume > 20 ml prior to randomization of the patient according to figure 1. OR
• 2-3 brain metastases, which are radiologically proven by MRI scan. The size of each metastasis must be between 3 mm and 4.0 cm in the largest diameter. Contrast-enhancements on MRI which are smaller than 3 mm in diameter are not considered. The patient should not be considered as a good candidate for stereotactic radiosurgery +/- whole brain radiotherapy.
• Each lesion has a distance of its margin to the chiasma opticum or the optic nerves of > 5 mm.
• Male or female, Age 18 years or older
• Laboratory requirements: hematological status must be documented.
• Platelets >30 x 109/l. If platelets are below 30 x 109/l then correction by transfusion is indicated before entry into the study according to institutional guidelines.
• Hemoglobin > 8 g/dl. If anemia is present to the extent that the hemoglobin is less than 8 g/dl then correction by transfusion and/or erythropoietin is indicated before entry into the study according to institutional guidelines.
• Before patient registration, written informed consent must be given according to ICH/GCP and national regulations.

Exclusion Criteria:

• Lesions located in the medulla oblongata or in the brainstem.
• Leptomeningeal metastases or meningosis carcinomatosa. If meningosis carcinomatosa is suspected on MRI, the presence of tumor cells in the liquor cerebrospinalis must be excluded prior study entry.
• Chemotherapy within 1 week prior to study treatment
• Need for systemic chemotherapy to control primary disease or extracranial metastases within 3 weeks after study treatment (assessed before randomization)
• Prior treatment for brain metastases other than chemotherapy or resection of brain metastases (with 2-10 measurable lesions remaining), prior cranial radiotherapy
• Severe coagulopathy
• Medical illnesses or psychiatric impairments which would prevent completion of protocol therapy
• Female patients who are pregnant at the time of entering the study. Women must agree to a beta-HCG pregnancy test if the possibility of pregnancy is believed to exist. Women and men of child bearing potential who are admitted to the trial will be advised that the treatment received may be teratogenic and are advised to take adequate measures to prevent conception.
• Participation in other clinical trials within 4 weeks prior registration.