CyberKnife Stereotactic Radiosurgery for Atypical and Malignant Meningiomas.
OBJECTIVE
Recurrent World Health Organization (WHO) grade II and III meningiomas have traditionally been treated by surgery alone, but early literature suggests that adjuvant stereotactic radiosurgery may greatly improve outcomes. We present the long-term tumor control and safety of a hypofractionated stereotactic radiosurgery regimen.


METHODS
Prospectively collected data of 44 WHO grade II and 9 WHO grade III meningiomas treated by CyberKnife for adjuvant or salvage therapy were reviewed. Patient demographics, treatment parameters, local control, regional control, locoregional control, overall survival, radiation history, and complications were documented.


RESULTS
For WHO grade II patients, recurrence occurred in 41%, with local, regional, and locoregional failure at 60 months recorded as 49%, 58%, and 36%. For WHO grade III patients, recurrence occurred in 66%, with local, regional, and locoregional failure at 12 months recorded as 57%, 100%, and 43%. The 60-month locoregional control rates for radiation naïve and experienced patients were 48% and 0% (P = 0.14). Overall, 7 of 44 grade II patients and 8 of 9 grade III patients had died at last follow-up. The 60-month and 12-month overall survival rates for grade II and III meningiomas were 87% and 50%, respectively. Serious complications occurred in 7.5% of patients.


CONCLUSIONS
Stereotactic radiosurgery for adjuvant and salvage treatment of WHO grade II meningioma using a hypofractionated plan is a viable treatment strategy with acceptable long-term tumor control, overall survival, and complication rates. Future studies should focus on radiation-naïve patients and local management of malignant meningioma.
Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA.
Michael
M
Zhang
Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA.
Allen L
AL
Ho
Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA.
Myreille
M
D'Astous
Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA.
Arjun V
AV
Pendharkar
Department of Radiation Oncology, Santa Clara Valley Medical Center, Santa Clara, California, USA.
Clara Y H
CY
Choi
Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA.
Patricia A
PA
Thompson
Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA.
Armine T
AT
Tayag
Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California, USA.
Scott G
SG
Soltys
Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California, USA.
Iris C
IC
Gibbs
Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA; Stanford Cancer Institute, Stanford University School of Medicine, Palo Alto, California, USA. Electronic address: sdchang@stanford.edu.
Steven D
SD
Chang
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008579:Meningioma / Q000401:mortality / Q000532:radiotherapy*; D008875:Middle Aged; D010347:Patient Care Planning; D011183:Postoperative Complications / Q000209:etiology; D011446:Prospective Studies; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed
Adjuvant; Atypical; CyberKnife; Hypofractionation; Malignant; Meningioma; Salvage