Multisession stereotactic radiosurgery for large vestibular schwannomas

Area of Science:

• Neurosurgery
• Radiation Oncology
• Oncology

Background:

• Vestibular schwannomas (VSs) are tumors that can present challenges for treatment, especially larger ones.
• Microsurgery is a common treatment, but radiosurgery is emerging as a feasible alternative.
• Multisession stereotactic radiosurgery (SRS) offers a non-invasive approach for managing VSs.

Purpose of the Study:

• To evaluate the outcomes of multisession stereotactic radiosurgery (SRS) for treating large vestibular schwannomas (VSs).
• To assess tumor control rates, hearing preservation, and adverse events in patients with large VSs treated with SRS.

Main Methods:

• A cohort of 33 large VSs (8-24 cm(3)) were treated with multisession SRS using the CyberKnife between 2003 and 2011.
• Treatment involved 2-5 fractions delivering 14-19.5 Gy.
• Patient characteristics included prior surgery, shunt placement, age variations, and neurofibromatosis.

Main Results:

• Radiological growth control was achieved in 94% of cases over a median follow-up of 48 months.
• Tumor size stabilized or reduced in 94% of patients; 36% experienced shrinkage after initial enlargement.
• Hearing was preserved in 7 of 8 patients with serviceable baseline hearing, and adverse events were minimal.

Conclusions:

• Multisession SRS demonstrates high tumor control rates for large VSs, supporting its role as an alternative to surgery.
• The findings may expand indications for radiation therapy in large VSs, even in asymptomatic patients.
• Further research is needed to confirm the widespread application of multisession SRS, particularly in younger patients.