Preservation of Cranial Nerve Function Following Gamma Knife Radiosurgery for Benign Skull Base Meningiomas: Experience in 121 Patients with Follow-up of 5 to 9.8 Years

OBJECTIVEGamma Knife radiosurgery (GKRS) has been successfully used for the treatment of intracranial meningiomas given its steep dose gradients and high-dose conformality. However, treatment of skull base meningiomas (SBMs) may pose significant risk to adjacent radiation-sensitive structures such as the cranial nerves. Fractionated GKRS (fGKRS) may decrease this risk, but until recently it has not been practical with traditional pin-based systems. This study reports the authors’ experience in treating SBMs with fGKRS, using a relocatable, noninvasive immobilization system.METHODSThe authors performed a retrospective review of all patients who underwent fGKRS for SBMs between 2013 and 2018 delivered using the Extend relocatable frame system or the Icon system. Patient demographics, pre- and post-GKRS tumor characteristics, perilesional edema, prior treatment details, and clinical symptoms were evaluated. Volumetric analysis of pre-GKRS, post-GKRS, and subsequent follow-up visits was performed.RESULTSTwenty-five patients met inclusion criteria. Nineteen patients were treated with the Icon system, and 6 patients were treated with the Extend system. The mean pre-fGKRS tumor volume was 7.62 cm3 (range 4.57–13.07 cm3). The median margin dose was 25 Gy delivered in 4 (8%) or 5 (92%) fractions. The median follow-up time was 12.4 months (range 4.7–17.4 months). Two patients (9%) experienced new-onset cranial neuropathy at the first follow-up. The mean postoperative tumor volume reduction was 15.9% with 6 patients (27%) experiencing improvement of cranial neuropathy at the first follow-up. Median first follow-up scans were obtained at 3.4 months (range 2.8–4.3 months). Three patients (12%) developed asymptomatic, mild perilesional edema by the first follow-up, which remained stable subsequently.CONCLUSIONSfGKRS with relocatable, noninvasive immobilization systems is well tolerated in patients with SBMs and demonstrated satisfactory tumor control as well as limited radiation toxicity. Future prospective studies with long-term follow-up and comparison to single-session GKRS or fractionated stereotactic radiotherapy are necessary to validate these findings and determine the efficacy of this approach in the management of SBMs.

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Gamma-Knife Radiosurgery for Skull Base Meningiomas: Experience of Tumor Control, Clinical Course and Morbidity in a Follow-Up of More Than 8 Years

Skull Base ◽

10.1055/s-2009-1222316 ◽

2009 ◽

Vol 19 (01) ◽

Author(s):

Brigitte Gatterbauer ◽

Iris Zachenhofer ◽

Klaus Kitz ◽

Karl Rössler ◽

Stefan Wolfsberger ◽

...

Keyword(s):

Skull Base ◽

Gamma Knife ◽

Clinical Course ◽

Gamma Knife Radiosurgery ◽

Tumor Control ◽

Skull Base Meningiomas

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Low-Dose Gamma Knife Radiosurgery for Vestibular Schwannomas: Tumor Control and Cranial Nerve Function Preservation After 11 Gy

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0036-1584231 ◽

2016 ◽

Vol 78 (01) ◽

pp. 002-010 ◽

Cited By ~ 1

Author(s):

Rohan Lall ◽

Rishi Lall ◽

Allan III ◽

Amit Ayer ◽

Samir Sejpal ◽

...

Keyword(s):

Gamma Knife ◽

Cranial Nerve ◽

Low Dose ◽

Gamma Knife Radiosurgery ◽

Vestibular Schwannomas ◽

Tumor Control ◽

Nerve Function ◽

Cranial Nerve Function ◽

Function Preservation

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Gamma knife radiosurgery in skull base meningiomas: a possible relationship between somatostatin receptor decrease and early neurological improvement without tumour shrinkage at short-term imaging follow-up

Acta Neurochirurgica ◽

10.1007/s00701-005-0483-9 ◽

2005 ◽

Vol 147 (4) ◽

pp. 367-375 ◽

Cited By ~ 9

Author(s):

A. Nicolato ◽

P. Giorgetti ◽

R. Foroni ◽

D. Grigolato ◽

I. P. Pasquin ◽

...

Keyword(s):

Skull Base ◽

Gamma Knife ◽

Somatostatin Receptor ◽

Gamma Knife Radiosurgery ◽

Short Term ◽

Neurological Improvement ◽

Tumour Shrinkage ◽

Skull Base Meningiomas

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Risk of injury to cranial nerves after gamma knife radiosurgery for skull base meningiomas: experience in 88 patients

Journal of Neurosurgery ◽

10.3171/jns.1999.90.1.0042 ◽

1999 ◽

Vol 90 (1) ◽

pp. 42-49 ◽

Cited By ~ 236

Author(s):

Akio Morita ◽

Robert J. Coffey ◽

Robert L. Foote ◽

David Schiff ◽

Deborah Gorman

Keyword(s):

Skull Base ◽

Gamma Knife ◽

Cranial Nerves ◽

Gamma Knife Radiosurgery ◽

Median Dose ◽

Trigeminal Neuropathy ◽

Content Type ◽

Skull Base Meningiomas ◽

Fine Print

Object. In this study the authors sought to determine the neurological risks and potential clinical benefits of gamma knife radiosurgery for skull base meningiomas.Methods. A consecutive series of 88 patients harboring skull base meningiomas were treated between 1990 and 1996 by using the Leksell gamma knife in a prospective clinical study that included a strict dose—volume protocol. Forty-nine patients had previously undergone surgery, and six had received external-beam radiotherapy. The median treatment volume was 10 cm3, and the median dose to the tumor margin was 16 Gy. The radiosurgical dosage to the optic nerve, the cavernous sinus, and Meckel's cave was calculated and correlated with clinical outcome. The median patient follow-up time was 35 months (range 12–83 months).Two tumors (2.3%) progressed after radiosurgery; the progression-free 5-year survival rate was 95%. At last follow-up review, 60 (68%) tumors were smaller and 26 (29.5%) remained unchanged. Clinical improvement (in vision, trigeminal pain, or other cranial nerve symptoms) occurred in 15 patients. Functioning optic nerves received a median dose of 10 Gy (range 1–16 Gy), and no treatment-induced visual loss occurred. Among nine patients with new trigeminal neuropathy, six received doses of more than 19 Gy to Meckel's cave.Conclusions. Gamma knife radiosurgery appeared to be an effective method to control the growth of most skull base meningiomas in this intermediate-term study. The risk of trigeminal neuropathy seemed to be associated with doses of more than 19 Gy, and the optic apparatus appeared to tolerate doses greater than 10 Gy. Considering the risks to cranial nerves associated with open surgery for comparable tumors, the authors believe that gamma knife radiosurgery is a useful method for the management of properly selected recurrent, residual, or newly diagnosed skull base meningiomas.

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