Microsurgery for Potential Radiosurgical Skull Base Lesions: A Retrospective Analysis and Comparison of Results

ABSTRACT

The outcomes of 26 complex skull base tumors treated with microsurgery were compared with the outcomes of similar tumors treated with radiosurgery as reported in the literature. The University neurosurgery database was searched for patients who underwent microsurgery for the treatment of skull base tumors between 1990 and 2001 at Louisiana State University Health Sciences Center in Shreveport, Louisiana. Twenty-six skull base meningiomas treated by microsurgery by the senior author (AN) were identified retrospectively. On imaging, the tumors were well defined and less than 3 cm in the greatest diameter, making them ideal candidates for a radiosurgical procedure had this modality been available. The follow-up and outcomes of these 26 patients were compared with the published outcomes of similar tumors treated with radiosurgery. Total excision was achieved in 17 (65.3%) patients. Excision was subtotal in 9 (34.6%) patients due to the critical locations of their tumors. The median hospital stay for these patients was 4 days (range, 3 to 12 days). Two patients (7.6%) had transient cerebrospinal fluid leaks from the wound, and 2 (7.6%) had transient facial paresis. Overall, preoperative symptoms improved in 23 (88.4%) patients. The median follow-up was 56 months (range, 3 to 120 months). The overall survival rate for all was 87.2 ± 3.7% at 50 months. Two patients (7.6%) subsequently underwent repeat surgery for a recurrent or progressive disease. The actuarial 8-year tumor control rate was 86.4 ± 4.4% using the Kaplan-Meier method. For small skull base tumors with benign histology, microsurgery is as safe and effective a treatment option as stereotactic radiosurgery. The symptomatic improvement in patients is better with microsurgery than with radiosurgery because the volume of the tumor is reduced immediately. A combined approach using both modalities is usually needed for larger tumors when attempts at total resection would jeopardize the neurologic function of the patient.

KEYWORDS

Gamma knife - microsurgery - radiosurgery - skull base tumor

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