Gamma Knife Radiosurgery (GKS) is well-tolerated and provides meaningful disease control for patients with meningiomas secondary to childhood brain radiation therapy (RT)Paul Aridgides1, Lisa Mitchell2, Jeffrey Bogart2, Seung Shin Hahn2, Chung-Taik Chung2, Anna Shapiro21Syracuse, United States 2SUNY Upstate Medical University, Department of Radiation Oncology, Syracuse NY Keywords: meningioma, radiosurgery, gamma knife, radiotherapy, outcome
Meningiomas are a potential long-term consequence of pediatric cranial radiotherapy (CRT).
We reviewed our experience with GKS for meningiomas arising in the setting of prior childhood CRT.
Between 1998 and 2010, 3 patients were retrospectively identified who had GKS for meningiomas after prior CRT as children (age < 18 years).
Treatment outcomes were reviewed including complication rate and treatment failure (follow-up 4.2 to 7.9 years). Progression was defined as having radiographic evidence of growth or requiring salvage treatment (radiosurgery or surgical excision). A cohort of 216 patients without a history of prior CRT was also examined.
Patients had received childhood cranial RT (ages 8 to 18 yrs) at a mean 21.3 yrs (range 16-24) prior to diagnosis of meningioma. Prior CRT consisted of whole brain radiation therapy for treatment of either : acute leukemia (24Gy), pineal dysgerminoma (36Gy), or low-grade astrocytoma (dose unavailable). Meningiomas were asymptomatic and identified on surveillance imaging for two patients. One patient had undergone craniotomy for symptomatic benign meningioma, and subsequently had recurrence within the resection bed. GKS was delivered in a single fraction (12 to 19 Gy). GKS was well-tolerated with no cases of symptomatic edema or other complications. One case of assymptomatic radiation necrosis was seen, which was self-limted. While 2 patients had evidence of local progression greater than 4 years out from GKS, both received salvage treatment (surgery or repeat GKS) and are alive with stable neurological symptoms. One patient remains progression-free (follow-up 4.2 years). Two patients also developed meningiomas of a separate intracranial site (treated by surgery or GKS). In our similarly treated cohort of 216 patients without prior history of brain RT (median follow-up 4.3 years), five-year progression free survival was 85%.
This was a retrospective study.
GKS for meningiomas arising after childhood cranial irradiation is well-tolerated and provides meaningful disease control, although patients appear at increased risk for both late local progression (>4 years out from GKS) and developing new meningiomas.
While our experience is limited to three patients, radiosurgery outcomes have been under-reported by our review and effective treatment strategies are necessary in this high-risk population. Project Roles:
P. Aridgides (), L. Mitchell (), J. Bogart (), S. Hahn (), C. Chung (), A. Shapiro ()