Gamma knife stereotactic radiosurgery for thalamic & brainstem cavernous angiomas.

Area of Science:

• Neurosurgery
• Neurology
• Radiation Oncology

Background:

• Symptomatic cavernous angiomas (CA) in the brainstem and thalamus pose significant treatment challenges due to their location in eloquent brain areas.
• The natural history of these CAs includes a high risk of symptomatic hemorrhage, leading to potential neurological deficits.

Purpose of the Study:

• To evaluate the safety and efficacy of Gamma Knife stereotactic radiosurgery (GKS) for treating symptomatic brainstem and thalamic cavernous angiomas (CA).
• To compare the outcomes of GKS treatment with the expected natural history of hemorrhage for these specific CA locations.

Main Methods:

• A consecutive series of 16 patients with thalamic or brainstem CA treated with GKS over 10 years were retrospectively analyzed.
• The GKS target excluded the haemosiderin ring. Patients had a history of one or more symptomatic hemorrhages prior to treatment.
• Follow-up included clinical and radiological assessments for a mean of 43.8 months.

Main Results:

• One patient experienced recurrent hemorrhage 23 months post-GKS, with no further bleeding in the subsequent 61 months.
• One patient died from thalamic hemorrhage from the treated lesion at 90 months; one patient was lost to follow-up.
• The remaining 13 patients showed no clinical or radiological evidence of post-GKS hemorrhage or complications. Annual hemorrhage rates were 3.72% within 2 years and 3.59% after 2 years post-GKS.

Conclusions:

• Gamma Knife stereotactic radiosurgery (GKS) demonstrates safety and efficacy in treating thalamic and brainstem cavernous angiomas (CA).
• The observed rate of re-hemorrhage after GKS is significantly lower than anticipated based on the natural history of hemorrhaging CAs in these critical brain regions.