For stereotactic radiation treatment, high radiation doses can be delivered with great precision to intracranial target areas, without the surrounding normal brain tissue being irradiated above the tolerance limit. Often a single radiation fraction is used, or possibly a few. The radiation dose in focus is then so high that the tissue in the small high-dose volume will die.
There are multiple equally effective techniques for stereotactic radiation treatment:
- Gamma Knife (radiation knife)
- linear accelerator
A gamma knife is mostly used for small tumors. The treatment is started and completed during one hospital stay. Haukeland University Hospital is the only hospital in Norway with a Gamma Knife. The technique will not described further here.
At Oslo University Hospital, the Radium Hospital, radiation therapy is carried out with a linear accelerator. This technique can also be used for larger tumors. The treatment is given in the form of several smaller radiation doses distributed over a number of weeks or as a single fraction.
A CyberKnife is a form of stereotactic treatment for delivering radiotherapy in which a linear accelerator is operated by a robot. The type of radiation and effect are otherwise equal to a gamma knife and/or linear accelerator. This system, however, is currently not available in Norway.
- Intracranial metastases (max. number, 2-3 metastases; max. diameter, approximately 3 cm)
- Small (max. 3 cm in diameter) Schwannomas or meningiomas
- Residual tumors after earlier operations for pituitary gland tumors
- Other benign tumors where operation involves risks
- Destroying the cancer cells' DNA and destroying the cancer cell
- Neutralize the intracranial cancer disease of intracranial metastases
- Limit radiation strain on surrounding brain tissue