The findings emphasized the necessity to plan the management of patients with cranial base meningiomas according to a 10- to 20-year perspective. Patients must be followed to evaluate the treatment results and to detect recurrences. Nonradical surgery must be viewed as a temporizing or palliative measure; a continued search for means of radical tumor treatment is warranted in these often surgically difficult tumors.

Adding early optic nerve decompression by extradural clinoidectomy and optic canal unroofing to a frontopterional approach seemed to improve visual outcomes because there were no instances of visual deterioration. Simpson Grade 1 to 2 removal was possible in all patients with primary surgery, whereas recurrent cases could only be treated with lower grades of radicality. Radical removal, however, required readiness to reoperate for cerebrospinal fluid leakage at the site of the drilled tumor origin in bone.

The high incidence of radiation-induced complications does not seem to justify the limited protection the treatment may afford in only exceptional cases. A prospective randomized study is needed before the role of radiosurgery in the management of these lesions can be defined. Until such a study has proved differently, a caveat must be raised for the treatment of CM with GKRS.

Over the long term, outcomes were worse following conservative treatment or shunt insertion surgery than after microsurgery of symptomatic cavernomas. Incidental cavernomas carried a low risk of neurological deterioration. Surgery should follow generally accepted indications, but only with the confidence that total removal can be safely achieved. Surgery that is performed within 10 to 30 days following ictus may be preferable to delayed surgery.

The current anatomic long-term analysis after thermocapsulotomy or gamma knife capsulotomy for obsessive-compulsive disorder reveals common topographic features within the right-sided anterior limb of the internal capsule independent of treatment modality.

Our experience with radiosurgery of brain metastases is based on 160 patients with 235 tumors treated over a 16-year period. In this material, 94% growth control was achieved. Radiosurgery appears to be an effective, low-morbidity substitute for surgical resection followed by whole brain radiotherapy and even indicated for multiple metastases and distant new tumors. More patients receive an effective treatment with less neurologically related deaths.

The Gamma Knife is currently the only radiosurgical device which has been used in functional neurosurgery. This mode of utilization is possible because the instrument can make lesions in normal brains with a volume as small as 50 mm³. The experience of functional radiosurgery accumulated at the Karolinska Institute over 21 years is reviewed, and the possible implications of the new developments in imaging techniques for the future of functional radiosurgery are considered. The review Covers gamma thalamotomy for pain and tremor, radiosurgery for trigeminal neuralgia, gamma capsulotomy for severe anxiety and obsessive-compulsive neurosis, and Gamma Knife surgery for focal epilepsy. The important role of stereotactic MRI localization in functional radiosurgery is pointed out, and a preliminary report of the recent experience with stereotactic magnetoencephalography combined with stereotactic MRI for physiological and anatomic target localization is given. It is concluded that functional radiosurgery should only be performed with radiation of very small volumes of brain, as the very high doses required would be devastating if delivered to even small volumes.

Long-term tumour growth of incidentally detected asymptomatic meningiomas appeared to be much higher than expected. This information needs to be considered when discussing surgery, since the indication for surgery may be stronger than previously stated, especially for younger patients with tumours that can be reached at low risk.