Stereotactic radiosurgery for trigeminal schwannomas.

Area of Science:

• Neurosurgery
• Radiation Oncology
• Oncology

Background:

• Trigeminal schwannomas (TS) are traditionally treated with microsurgery, which can lead to significant morbidity.
• Complete surgical excision of TS is often challenging.
• Stereotactic radiosurgery (SRS) presents a less invasive alternative for TS management.

Purpose of the Study:

• To evaluate the cumulative experience and effectiveness of SRS in treating trigeminal schwannomas.
• To assess tumor control, progression-free survival, and adverse effects of SRS for TS.

Main Methods:

• Seventy-four patients with TS, including four with neurofibromatosis type 2 (NF2), were treated with Leksell Gamma Knife SRS.
• The average tumor volume was 5.3 cm³, treated with a mean marginal dose of 16.4 Gy.
• Forty percent of patients had prior surgical treatment for their tumors.

Main Results:

• Tumor size remained stable in 78.4% of patients and shrank in 14.9%.
• Tumor progression occurred in 6.6% of patients, with a 5-year progression-free survival of 92.7% and 10-year PFS of 79.4%.
• NF2 patients showed significantly worse outcomes (p=0.001), with 5-year PFS of 50%.

Conclusions:

• SRS is an effective treatment for both newly diagnosed and residual trigeminal schwannomas.
• The Gamma Knife should be considered for a more prominent role in treating TS.
• While generally safe, adverse radiation effects were noted in seven patients, and improvements in cranial nerve function were observed in eight.