The role of stereotactic radiosurgery in the treatment of malignant skull base tumors

Purpose: To determine the efficacy and toxicity of stereotactic radiosurgery in the treatment of malignant skull base tumors, Methods and Materials: Thirty-two patients with 35 newly diagnosed or recurrent malignant skull base tumors less than or equal to 33.5 cm(3) were treated using the Leksell Gamma unit, Tumor histologies included: adenoid cystic carcinoma [12], basal cell carcinoma [1], chondrosarcoma [1], chordoma [8], nasopharyngeal carcinoma [3], osteogenic sarcoma [2], and squamous cell carcinoma [8], Results: After a median follow-up of 2.3 years, 83% +/- 15% (+/-95% confidence interval) of patients experienced a symptomatic response to treatment, Local control at the skull base was 95 +/- 9% at 2 years and 78 +/- 23% at 3 years. Local-regional control above the clavicles was 75 +/- 15% at 1 year and 51 +/- 20% at 2 years, Overall and cause specific survival were identical, 82 +/- 13% at 1 year, 76 +/- 14% at 2 years, and 72 +/- 16% at 3 years, One patient developed a radiation-induced optic neuropathy 12 months after radiosurgery, Conclusion: Stereotactic radiosurgery using the Leksell Gamma Unit can provide durable tumor control and symptomatic relief with acceptable toxicity in the majority of patients with malignant tumors 4 cm or less in size involving the skull base, Further evaluation of more patients with longer follow-up is warranted. (C) 1997 Elsevier Science Inc.