Linac-based radiosurgery or hypofractionated stereotactic radiotherapy in the treatment of large cerebral arteriovenous malformations.
OBJECTIVE
We investigate retrospectively clinical outcome after radiosurgery (RS) or hypofractionated stereotactic radiotherapy (HSRT) in patients with large cerebral arteriovenous malformations (AVMs).


METHODS
This analysis is based on 48 patients with cerebral AVM greater than 4 cm treated with HSRT or RS at our institution. Fifteen patients received HSRT, with 26 Gy median total dose in 4 to 5 fractions, and 33 patients received RS with 17 Gy median total dose in 4 to 5 fractions. Median target volume was 27 cc in HSRT and 7 cc in RS; median maximum diameter was 6 cm and 5 cm, respectively. Seventeen patients experienced intracranial hemorrhage before treatment. Median follow-up was 2.6 years.


RESULTS
The 3-year and 4-year actuarial complete obliteration (CO) after HSRT was 17% and 33% and after RS was 47% and 60%, respectively. Actuarial CO was higher in AVMs less than 5 cm (66% vs. 37% after 4 years). Intracranial hemorrhage after HSRT occurred in 3 of 15 patients after 18 months median, and after RS in 7 of 33 patients after 17 months median. Bleeding risk was significantly higher in patients with prior hemorrhage (p < 0.04). Preexisting neurologic dysfunction improved/dissolved in 50% and remained stable in 45%.


CONCLUSIONS
Large AVMs need a long time period to obliterate and show a high bleeding risk. Multimodal treatment strategies are required to reduce treatment volume before radiotherapy.
Zabel-du Bois
Angelika
A
Department of Radiooncology, University of Heidelberg, Heidelberg, Germany. A.Zabel@dkfz-heidelberg.de
Milker-Zabel
Stefanie
S
Huber
Peter
P
Schlegel
Wolfgang
W
Debus
Jürgen
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000473:pathology / Q000601:surgery*; D020300:Intracranial Hemorrhages / Q000209:etiology; D008297:Male; D008875:Middle Aged; D019106:Postoperative Hemorrhage / Q000209:etiology; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D016896:Treatment Outcome