Inclusion Criteria:

1. Male or female ages over 18 years old that give informed written consent to
participate in study. Females in reproductive age have to provide a negative serum
pregnancy test.

2. Patients with primary diagnosis (biopsy proven) of a malignant glioma or a recurrent
glioma, that do not accept a conventional tumor resection or where a conventional
tumor resection is not indicated according to both the neurosurgeon in charge and the
neuro-oncology colloquium at the Kantonsspital Aarau.

Or:

Patients with a supratentorial brain metastasis of a malignant tumor, that do not
accept a conventional tumor resection or where a conventional tumor resection is not
indicated according to the neurosurgeon in charge and the neuro-oncology colloquium
at the Kantonsspital Aarau.

3. The portion of the tumor to be treated during one intervention is less than 3.0 cm in
diameter, corresponding to a volume of ca. 14 cc.

If the total size of the tumor is larger than 3.0 cm in diameter then eventual
complementing ablations will not be performed before 2 week after the first
treatment.

4. The tumor to be treated is clearly defined and can be well distinguished from
surrounding brain tissue.

5. The border of the targeted tumor volume has in all directions a distance of at least
2.5 cm from the inner table of the skull. Portions of the tumor that are not planned
to be treated due to this safety margin will be marked.

6. Patients must have an ASA score 1-2, and a Karnofsky score 70-100

Exclusion Criteria:

All tumor Types

1. Clinical or neuroradiological signs of increased intracranial pressure.

2. Significantly increased vascularization of tumor in preoperative MR-angiogram or in
digital subtraction angiography (DSA).

3. Tumor mass effect that causes midline shift or a shift of the third (3rd) ventricle
of more than 5 mm, even after steroid therapy.

4. The border of the tumor portion to be treated is less then 5mm away from a main
branch of a brain vessel, the venous sinuses, the pituitary gland or the cranial
nerves.

5. The tumor is in immediate proximity to a cystic formation.

6. Recent (less than 2 weeks) intracranial hemorrhage.

7. Increased risk of bleeding: platelets < 100,000/mm3, INR > 1.3 or other coagulation
disorders.

8. Tumors with presumably high risk of bleeding

9. Oral anticoagulant or thrombocyte aggregation suppression (e.g. ASS) that was not
stopped at least 5 days before the intervention.

10. Contraindication for MR-exams, such as non-MR-compatible implants or cardiac
pacemaker.

11. Clips and other implants in the sonication path or in the target area.

12. Operation implantates such as durapatch, skullreconstruction with
polymethylmethacrylate (PalacosTM), titan in the sonication path.

13. Infratentorial (i.e. cerebellar-) tumors.

14. Contraindications for MR-contrast agents or for steroid therapy

15. Allergy against local anesthesia.

16. Uncontrolled arterial hypertension.

17. Other life threatening diseases.

18. Severe uncontrolled systemic infection.

19. Hypersensitivity to contrast agents used in this study.

20. Severely impaired renal function (estimated glomerular filtration rate < 30
mL/min/1.73 m2) or under dialysis.

21. Inability to give informed written consent.

22. Alcohol or drug abuse.

23. Patients who are unreliable and will not appear for the follow up exams.