The role of Gamma Knife radiosurgery in the management of glomus jugular tumours.

BACKGROUND: Glomus jugular tumours are usually managed by microsurgical resection and/or radiotherapy with considerable risk for treatment-related morbidity. The role of Gamma Knife Radiosurgery (GKRS) in the management of these lesions remains to be defined.

METHOD: Between May 1992 and November 2000, 19 patients with glomus tumours underwent GKRS at our department. Nine patients received radiosurgery for residual or recurrent paragangliomas following microsurgical resection and in 10 cases GKRS was performed as primary treatment. The median tumour volume was 5.22 ccm (range: 0.38-33.5 ccm). Marginal doses of 12-20 Gy (median 14 Gy) were applied to enveloping isodose volume curves (Range: 30-55%, median 50%).

FINDINGS: Except for an 81-year-old patient who died 9 months after radiosurgery the observation time ranged from 1.5 to 10 years (median 7.2 yrs). The total tumour control rate was 94.7% (7 cases with decreased and 11 with stable tumour size). The only patient with tumour progression (5.3%) underwent repeated radiosurgical treatment 85 months after initial GKRS. A newly diagnosed second lesion in the cavernous sinus was treated radiosurgically as well 53 months after the first Gamma Knife procedure. On clinical examination 10 patients (52.6%) presented with improved and 8 patients (42.1%) with unchanged neurological status. Deterioration in one patient (5.3%) was not related to tumour or radiosurgery.

INTERPRETATION: As GKRS demonstrated to be a minimally invasive treatment alternative to microsurgery and radiotherapy with no acute or chronic toxicity it should be considered more frequently in the primary or adjuvant strategy for glomus jugular tumours.