Gamma knife radiosurgery for glomus jugulare tumors: Therapeutic advantages of minimalism in the skull base

Context: Glomus jugulare (GJ) tumors are paragangliomas found in the region of the jugular foramen. Surgery with/without embolization and conventional radiotherapy has been the traditional management option.
Aim: To analyze the efficacy of gamma knife radiosurgery (GKS) as a primary or an adjunctive form of therapy.
Settings and Design: A retrospective analysis of patients who received GKS at a tertiary neurosurgical center was performed.
Materials and Methods: Of the 1601 patients who underwent GKS from 1997 to 2006, 24 patients with GJ underwent 25 procedures.
Results: The average age of the cohort was 46.6 years (range, 22-76 years) and the male to female ratio was 1:2. The most common neurological deficit was IX, X, XI cranial nerve paresis (15/24). Fifteen patients received primary GKS. Mean tumor size was 8.7 cc (range 1.1-17.2 cc). The coverage achieved was 93.1% (range 90-97%) using a mean tumor margin dose of 16.4 Gy (range 12-25 Gy) at a mean isodose of 49.5% (range 45-50%). Thirteen patients (six primary and seven secondary) were available for follow-up at a median interval of 24 months (range seven to 48 months). The average tumor size was 7.9 cc (range 1.1-17.2 cc). Using a mean tumor margin dose of 16.3 Gy (range 12-20 Gy) 93.6% coverage (range 91-97%) was achieved. Six patients improved clinically. A single patient developed transient trigeminal neuralgia. Magnetic resonance imaging follow-up was available for 10 patients; seven recorded a decrease in size. There was no tumor progression.
Conclusions: Gamma knife radiosurgery is a safe and effective primary and secondary modality of treatment for GJ.

Keywords
Follow-up, gamma knife, glomus jugulare tumor, stereotactic radiosurgery, surgery