Glomus jugulare tumors: The option of gamma knife radiosurgery

OBJECTIVE: Glomus jugulare tumors are generally considered slow-growing, benign lesions. However, their pronounced local aggressiveness frequently results in severe neurological deficits. Surgical removal is rarely radical and is usually associated with morbidity. There is increasing evidence that stereotactic radiosurgery, particularly gamma knife radiosurgery (GKR), may play a relevant role as a therapeutic option in these tumors. METHODS: Between 1996 and 2005, we used GKR to treat 20 patients bearing growing glomus jugulare tumors, mostly classified as Glasscock-Jackson Grade IV or Fisch Stage D1. Follow-up (mean, 50.85 mo) data was available for 20 patients (four men, 16 women; mean age, 56 yr): eight out of 20 tumors were surgical recurrences, three out of 20 patients had GKR as the primary treatment, and 11 out of 20 patients previously underwent endovascular embolization. Regarding the radiosurgical dose planning, the average tumor volume was 7.03 cm(3) (range, 1.5-13.4 cm(3)) and the mean marginal dose was 17.3 Gy (range, 13-24 Gy). RESULTS: Neurological signs and symptoms were unchanged in 13 out of 20 patients. An improvement of cranial nerve function was observed in five patients and hearing deterioration was observed in two patients. Tumor volume was unchanged in I I out of 20 patients and was slightly (<= 20%) decreased in eight out of 20 patients. In one unusual case of a bulky cavernous sinus recurrence, neoplastic regression was particularly pronounced. CONCLUSION: Despite the constraints of the limited case material, considering the estimated doubling time of these rare tumors (4.2 yr), our preliminary results with GKR at a mid-term follow-up examination suggest an effective tumor growth control with negligible incidence of untoward sequelae.