Leksell Gamma Knife Radiosurgery of the Tumor Glomus Jugulare and Tympanicum

Abstract

We have treated 14 patients with glomus tumor during the 4 years (of 1993 to 1997) using Leksell Gamma Knife radiosurgery. The male: female ratio was 1:3.7, and the mean age 48.6 years (range 22–75 years). The mean tumor volume was 5.5 cm³ (range 0.7–11.3 cm³). The mean maximum dose was 37.4 Gy (range 20–44 Gy). The mean margin dose was 19.4 Gy (range 10–25 Gy). In 3 patients, infrabasal spread of the tumor could not be delineated on peroperative stereotactic CT scans. As a result, this portion of the tumor was treated in 2 patients at a second stage using stereotactic MRI. Follow-up in 11 patients ranged from 6 to 42 months (mean 20.5 months). Hearing on the affected side was further impaired in 3 patients. Tinnitus, vertigo and ataxia improved in 3 patients, headache and nausea in 2 patients. Angiography after radiosurgery was performed in 3 patients. In one patient 12 months after the radiosurgery, pathological vascularisation had completely disappeared. In another patient pathological vascularisation was still present 22 months after the first stage, despite two-stage radiosurgery, although the tumor volume decreased 30%. In the last patient, vascularisation and tumor volume partially decreased 12 months after radiosurgery. The volume of the tumor decreased in 4 patients. No change in tumor volume has been observed in any of the other patients to date. Radiosurgery proves to be a safe treatment for glomus tumor with no acute morbidity. Because of its naturally slow growth rate, up to 10 years follow-up will probably be necessary to establish the therapeutic effectiveness of radiosurgery for glomus tumor.

Microsurgical treatment of large and giant tympanojugular paragangliomas

“…Stereotactic radiosurgery revealed high rates of tumor growth control and relatively low morbidity in recent series. [ 2 4 11 14 15 16 17 18 24 26 45 ] Their results are supported by two meta-analyses that maintain the advantage of radiotherapy including radiosurgery of TJP compared to microsurgery. [ 21 45 ] The evidence is mainly based on retrospective studies.…”

“…[ 49 ] The time interval between the first symptom and diagnosis is estimated to be 4–6 years. [ 26 ]…”

“…[ 25 ] Recent studies have explored radiosurgery for TJP as a primary treatment. [ 2 4 11 14 15 16 17 18 24 26 45 ] The beneficial effects of radiosurgery are comparable to their application on cerebral arteriovenous malformations. The precise stereotactic localization and the combined steep dose gradient outside the target volume allow the application of a large single doses to a precisely defined lesion.…”

“…Fractionated radiotherapy, stereotactic radiosurgery, gamma knife radiosurgery, and cyberknife radiosurgery as the primary treatment revealed high rates of tumor growth control and relatively low morbidity in recent series. [ 2 4 11 14 15 16 17 18 19 24 26 45 ] Surgery for large TJP is challenging due to their high vascularity and close relationship with delicate neural and vascular structures. [ 1 27 39 ] However, favorable long-term results can be achieved by combining surgical expertise from specialized neurosurgeons, ENT surgeons, and interventional neuroradiologists in the planning and execution of surgery.…”

A Retrospective Analysis of Tumor Volumetric Responses to Five-Fraction Stereotactic Radiotherapy for Paragangliomas of the Head and Neck (Glomus Tumors)

“…Using the Universal Survival Model and an α/β ratio of 3 for a paraganglioma, a dose of 25 Gy in five fractions was calculated to be equivalent to 18 Gy in a single fraction [6]. Another reason for the five-fraction approach in our series is that the mean tumor volume of 10.7 cm 3 in our series is approximately twice the size of typical volumes cited in Gamma Knife radiosurgery series [8,22,23,24,25]. Thus, Gamma Knife radiosurgery would be unable to deliver a safe single dose that would provide a high likelihood of LC with the larger tumors in our series.…”