Radiosurgery of Malignant Tumors of the Skull Base

Objective: Proximity to critical neurovascular structures makes the treatment of malignant tumors that involve the skull base challenging for the clinician. Complete surgical resection can be associated with major morbidity. The goal of this study was to assess the safety and efficacy of fractionated radiosurgery of patients with skull base malignancies.

Methods: A retrospective analysis of clinical and radiographic data was performed for 37 patients treated with image-guided, fractionated radiosurgery between January 2002 and December 2007. Included lesions were those that involved the bones of the base of the skull with proximity to cranial nerves.

Results: The mean follow-up was 50 weeks. Fifteen patients (41%) were alive at the end of the follow-up period. An overall tumor control rate of 77% was achieved as 26 lesions exhibited either tumor regression or stable local disease at the last follow-up or at the time of death from systemic disease. For lesions that progressed, the mean time to progression was 47 weeks. The mean progression-free survival was 44 weeks. There were no toxicities of cranial nerve, brainstem, or vascular function referable to this technique.

Conclusion: Multisession radiosurgery for the treatment of malignant skull base tumors is safe and efficacious. Further investigation is required to optimize dosing and other treatment planning parameters.