Radiosurgery should also be considered in an asymptomatic patient if there is a likely probability of future visual symptoms. When a large meningioma involves the optic apparatus, internal carotid, or anterior cerebral arteries with dense adherence surgery can have higher risks. The management of the parasellar meningioma remains a challenge because of their poor surgical accessibility and proximity to critical neurovascular structures. Radiosurgery for the meningioma is recommended when there has been a subtotal removal with an inadequate decompression, or there is evidence of recurrence on MRI after radical subtotal removal. The radiosurgery of the parasellar meningioma allows the safe escalation of the dose to the tumor via fractionation.
Fractionation spares the optic apparatus while resulting in killing of the meningiomas.
Radiosurgery delivers high dose to the meningioma with sparing of the surrounding normal structures. R adiosurgery allows deposition of high doses of radiation in the meningioma with sparing of the surrounding normal structures including the optic nerves and optic chiasm. Although the carotid arteries may in some cases receive radiation, the arteries have not occluded after radiosurgery. The tolerance of the optic nerves and chiasm is more limited. Not only is the treatment safer with fractionation, but the total dose may be escalated when compared to single fraction techniques, resulting in potentially higher rates of tumor control.