Purpose: Evaluate the use of helium charged particle radiotherapy in the treatment of residual or unresectable meningioma adjacent to critical structures.
Methods and materials: Twenty-nine patients with meningioma of the skull base or spine were irradiated with helium charged particle radiotherapy at the University of California Lawrence Berkeley Laboratory (UCLBL) during the period 1981-1992. Twenty-six patients were treated for intracranial and three for spinal tumors. Total doses of 53.0-80.4 Gray equivalent (GyE) with a mean of 63 GyE were delivered using the helium ion beam.
Results: Ten-year local control and survival rates calculated by the Kaplan-Meier product limit method were 84% and 80% respectively. Doses of 60.0 GyE were delivered with a low rate of complications. The only failures were in massive, recurrent tumors.
Conclusion: High doses using helium charged particle radiotherapy can be safely and effectively delivered to large residual or unresectable meningioma near radiosensitive structures.