Gamma Knife surgery for the management of glomus tumors: a multicenter study.

Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia 22908, USA.
Journal of Neurosurgery (Impact Factor: 3.15). 06/2012; 117(2):246-54. DOI: 10.3171/2012.4.JNS11214
Source: PubMed

ABSTRACT Glomus tumors are rare skull base neoplasms that frequently involve critical cerebrovascular structures and lower cranial nerves. Complete resection is often difficult and may increase cranial nerve deficits. Stereotactic radiosurgery has gained an increasing role in the management of glomus tumors. The authors of this study examine the outcomes after radiosurgery in a large, multicenter patient population.
Under the auspices of the North American Gamma Knife Consortium, 8 Gamma Knife surgery centers that treat glomus tumors combined their outcome data retrospectively. One hundred thirty-four patient procedures were included in the study (134 procedures in 132 patients, with each procedure being analyzed separately). Prior resection was performed in 51 patients, and prior fractionated external beam radiotherapy was performed in 6 patients. The patients' median age at the time of radiosurgery was 59 years. Forty percent had pulsatile tinnitus at the time of radiosurgery. The median dose to the tumor margin was 15 Gy. The median duration of follow-up was 50.5 months (range 5-220 months).
Overall tumor control was achieved in 93% of patients at last follow-up; actuarial tumor control was 88% at 5 years postradiosurgery. Absence of trigeminal nerve dysfunction at the time of radiosurgery (p = 0.001) and higher number of isocenters (p = 0.005) were statistically associated with tumor progression-free tumor survival. Patients demonstrating new or progressive cranial nerve deficits were also likely to demonstrate tumor progression (p = 0.002). Pulsatile tinnitus improved in 49% of patients who reported it at presentation. New or progressive cranial nerve deficits were noted in 15% of patients; improvement in preexisting cranial nerve deficits was observed in 11% of patients. No patient died as a result of tumor progression.
Gamma Knife surgery was a well-tolerated management strategy that provided a high rate of long-term glomus tumor control. Symptomatic tinnitus improved in almost one-half of the patients. Overall neurological status and cranial nerve function were preserved or improved in the vast majority of patients after radiosurgery.

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    ABSTRACT: Object Jugulotympanic paragangliomas (JTPs) are rare benign tumors whose surgical treatment is usually associated with partial resection of the lesion, high morbidity, and even death. Gamma Knife radiosurgery (GKRS) has been reported as a useful treatment option. The goal of this retrospective study is to analyze the role of GKRS in tumor volume control and clinical outcomes of these patients. Methods A total of 75 patients with JTPs were treated with GKRS at the authors' center from 1995 to 2012. The authors analyzed those treated during this period to allow for a minimal observation time of 2 years. The MR images and clinical reports of these patients were reviewed to assess clinical and volumetric outcomes of the tumors. The radiological and clinical assessments, along with a group of prognostic factors measured, were analyzed using descriptive methods. The time to volumetric and clinical progression was analyzed using the Kaplan-Meier method. Prognostic factors were identified using log-rank statistics and multivariate Cox regression models. Results The mean follow-up was 86.4 months. The authors observed volumetric tumor control in 94.8% of cases. In 67.2% of cases, tumor volume decreased by a mean of 40.1% from the original size. Of patients with previous tinnitus, 54% reported complete recovery. Improvement of other symptoms was observed in 34.5% of cases. Overall, clinical control was achieved in 91.4% of cases. Previous embolization and familial history of paraganglioma were selected as significant prognostic factors for volumetric response to GKRS treatment in the univariate analysis. In multivariate analysis, no factors were significantly correlated with progression-free survival. No patient died of side effects related to GKRS treatment or tumor progression. Conclusions Gamma Knife radiosurgery is an effective, safe, and efficient therapeutic option for the treatment of these tumors as a first-line treatment or in conjunction with traditional surgery, endovascular treatment, or conventional fractionated radiotherapy.
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    ABSTRACT: Background: Skull base paragangliomas (SBP) are locally expansile tumors that can be treated with stereotactic radiotherapy with favorable results. This report describes the results of 31 patients with SBP treated with CyberKnife radiotherapy delivering a total dose of 25 Gray in five fractions. Methods: All patients treated with five-fraction CyberKnife radiotherapy at a single institution were identified between 2007 and 2013. Tumor volumetric analyses were performed to assess responses to radiotherapy. Results: Median follow-up was 24 months with a range of 4-78 months. Local control and overall survival were 100%. Of the 20 patients who presented with tinnitus, 12 reported improvement (60%), of whom 6 reported complete resolution. There was a 37.3% reduction in tumor volume among all patients (p = 0.16). On subset analysis of patients with ≥24 months of follow-up, tumor volume decreased 49% (p = 0.01). The rate of grade 1-2 toxicity was 19%, with no grade 3 or worse toxicity. Conclusion: A five-fraction CyberKnife-based stereotactic radiotherapy approach is safe and efficacious for the management for patients with SBP. Our findings suggest the potential use of this strategy as a definitive or salvage treatment option for SBP. © 2014 S. Karger AG, Basel.
    Stereotactic and Functional Neurosurgery 05/2014; 92(3):153-159. · 1.46 Impact Factor
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    ABSTRACT: To define the role of wait-and-scan and radiotherapy (RT) in the treatment of temporal bone paragangliomas and to review the literature on the outcomes of RT as a treatment modality. This was a retrospective and literature review. The records of 381 patients with 382 tumors between 1988 and 2012 were analyzed. Patients who were subjected to initial wait-and-scan or primary RT were analyzed for tumor response, facial, and lower cranial nerve status on follow-up (FU). None of the 145 patients (38%) with Class A and B tumors were subjected to wait-and-scan or RT and all were operated on. Of the 237 patients (62%) with Class C and D tumors, 47 (19.8%) were subjected to an initial wait-and-scan policy and 1 (0.4%) underwent primary RT. In 24 patients subjected to wait-and-scan with a FU of less than 3 years, tumor remained stable in 22 patients (92%). In 12 patients with a FU between 3 and 5 years, the tumor remained stable or regressed in 10 patients (83%). In 11 patients with a FU of more than 5 years, the tumor remained stable or regressed in 5 patients (45%). A literature review of the results of RT did not conclusively prove that it was effective as a primary modality of treatment for temporal bone paragangliomas. In elderly patients with advanced tumors, a wait-and-scan approach is recommended, and RT is initiated only when fast-growing tumors are detected. There is insufficient evidence in literature to suggest that RT could be an effective alternative to surgery in Class C and D tumors.
    Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 04/2014; · 1.44 Impact Factor


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Shota Tanaka