Intracranial meningiomas: factors that influence the development of cerebral edema after stereotactic radiosurgery and radiation therapy.
OBJECTIVE
To evaluate causative factors of cerebral edema after stereotactic radiosurgery or stereotactic radiation therapy in intracranial meningiomas.


METHODS
Of 43 adult patients with intracranial meningiomas, three received 13.5-18-Gy single-fraction stereotactic radiosurgery; one received 19.8 Gy in three fractions, one received 42 Gy in six fractions, and 31 received 32-36 Gy in six to eight fractions of stereotactic radiation therapy; and seven received 45-54-Gy external-beam radiation with 20-28 Gy in five to seven fractions as concomitant stereotactic boosts. Brain edema was estimated by calculating the edema index.


RESULTS
After irradiation, all 11 patients with parasagittal and four patients with nonparasagittal tumors developed worsening cerebral edema that necessitated the administration of steroids (P < .001). The statistically significant factors for the development of edema were parasagittal location, presence of pretreatment edema, sagittal sinus occlusion, and the use of more than 6 Gy per fraction. Five patients with parasagittal tumors developed life-threatening panhemispheric edema, which was fatal in one. The causative factors of panhemispheric edema were a large tumor, single-fraction stereotactic radiosurgery, or use of more than 6 Gy per fraction.


CONCLUSIONS
A smaller dose per fraction and aggressive use of steroids may help prevent life-threatening complications due to worsening edema.
Kalapurakal
J A
JA
Department of Radiation Oncology, Temple University School of Medicine, Philadelphia, PA 19140, USA.
Silverman
C L
CL
Akhtar
N
N
Laske
D W
DW
Braitman
L E
LE
Boyko
O B
OB
Thomas
P R
PR
D001929:Brain Edema / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D003131:Combined Modality Therapy; D003907:Dexamethasone / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000532:radiotherapy / Q000601:surgery / Q000628:therapy*; D008579:Meningioma / Q000532:radiotherapy / Q000601:surgery / Q000628:therapy*; D008875:Middle Aged; D016634:Radiosurgery; D011882:Radiotherapy, High-Energy
D003907:Dexamethasone