TY - JOUR
T1 - Stereotactic radiosurgery for arteriovenous malformations, Part 5
T2 - Management of brainstem arteriovenous malformations: Clinical article
AU - Kano, Hideyuki
AU - Kondziolka, Douglas
AU - Flickinger, John C.
AU - Yang, Huai Che
AU - Flannery, Thomas J.
AU - Niranjan, Ajay
AU - Novotny, Josef
AU - Lunsford, L. Dade
PY - 2012/1
Y1 - 2012/1
N2 - Object. In this paper, the authors' goal was to define the long-term outcomes and risks of stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) of the medulla, pons, and midbrain. Methods. Between 1987 and 2006, the authors performed Gamma Knife surgery in 996 patients with brain AVMs; 67 patients had AVMs in the brainstem. In this series, 51 patients (76%) had a prior hemorrhage. The median target volume was 1.4 cm 3 (range 0.1-13.4 cm 3). The median margin dose was 20 Gy (range 14-25.6 Gy). Results. Obliteration of the AVMs was eventually documented in 35 patients at a median follow-up of 73 months (range 6-269 months). The actuarial rates of documentation of total obliteration were 41%, 70%, 70%, and 76% at 3, 4, 5, and 10 years, respectively. Higher rates of AVM obliteration were associated only with a higher margin dose. Four patients (6%) suffered a hemorrhage during the latency period, and 2 patients died. The rate of AVM hemorrhage after SRS was 3.0%, 3.0%, and 5.8% at 1, 5, and 10 years, respectively. The overall annual hemorrhage rate was 1.9%. Permanent neurological deficits due to adverse radiation effects (AREs) developed in 7 patients (10%) after SRS, and a delayed cyst developed in 2 patients (3%). One patient died at an outside institution with symptoms of AREs and unrecognized hydrocephalus. Higher 12-Gy volumes and higher Spetzler-Martin grades were associated with a higher risk of symptomatic AREs. Ten of 22 patients who had ocular dysfunction before SRS had improvement, 9 were unchanged, and 3 were worse due to AREs. Eight of 14 patients who had hemiparesis before SRS improved, 5 were unchanged, and 1 was worse. Conclusions. Although hemorrhage after obliteration did not occur in this series, patients remained at risk during the latency interval until obliteration occurred. Thirty-eight percent of the patients who had neurological deficits due to prior hemorrhage improved. Higher dose delivery in association with conformal and highly selective SRS is required for safe and effective radiosurgery.
AB - Object. In this paper, the authors' goal was to define the long-term outcomes and risks of stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) of the medulla, pons, and midbrain. Methods. Between 1987 and 2006, the authors performed Gamma Knife surgery in 996 patients with brain AVMs; 67 patients had AVMs in the brainstem. In this series, 51 patients (76%) had a prior hemorrhage. The median target volume was 1.4 cm 3 (range 0.1-13.4 cm 3). The median margin dose was 20 Gy (range 14-25.6 Gy). Results. Obliteration of the AVMs was eventually documented in 35 patients at a median follow-up of 73 months (range 6-269 months). The actuarial rates of documentation of total obliteration were 41%, 70%, 70%, and 76% at 3, 4, 5, and 10 years, respectively. Higher rates of AVM obliteration were associated only with a higher margin dose. Four patients (6%) suffered a hemorrhage during the latency period, and 2 patients died. The rate of AVM hemorrhage after SRS was 3.0%, 3.0%, and 5.8% at 1, 5, and 10 years, respectively. The overall annual hemorrhage rate was 1.9%. Permanent neurological deficits due to adverse radiation effects (AREs) developed in 7 patients (10%) after SRS, and a delayed cyst developed in 2 patients (3%). One patient died at an outside institution with symptoms of AREs and unrecognized hydrocephalus. Higher 12-Gy volumes and higher Spetzler-Martin grades were associated with a higher risk of symptomatic AREs. Ten of 22 patients who had ocular dysfunction before SRS had improvement, 9 were unchanged, and 3 were worse due to AREs. Eight of 14 patients who had hemiparesis before SRS improved, 5 were unchanged, and 1 was worse. Conclusions. Although hemorrhage after obliteration did not occur in this series, patients remained at risk during the latency interval until obliteration occurred. Thirty-eight percent of the patients who had neurological deficits due to prior hemorrhage improved. Higher dose delivery in association with conformal and highly selective SRS is required for safe and effective radiosurgery.
KW - Arteriovenous malformation
KW - Brainstem
KW - Complications
KW - Gamma Knife surgery
KW - Stereotactic radiosurgery
UR - http://www.scopus.com/inward/record.url?scp=84855385596&partnerID=8YFLogxK
U2 - 10.3171/2011.9.JNS11176
DO - 10.3171/2011.9.JNS11176
M3 - Article
C2 - 22077450
AN - SCOPUS:84855385596
SN - 0022-3085
VL - 116
SP - 44
EP - 53
JO - Journal of Neurosurgery
JF - Journal of Neurosurgery
IS - 1
ER -