gms | German Medical Science

57th Annual Meeting of the German Society of Neurosurgery
Joint Meeting with the Japanese Neurosurgical Society

German Society of Neurosurgery (DGNC)

11 - 14 May, Essen

Gamma Knife radiosurgery of brainstem AVM: long-term analysis

Gamma-Knife-Radiochirurgie von hirnstammsnahen arterio-venösen Missbildungen: Eine Langzeitstudie

Meeting Abstract

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  • corresponding author B.E. Lippitz - RWTH Aachen, Neurochirurgische Klinik
  • B. Karlsson - West Virginia University Hospital Morgantown, Gamma Knife Center
  • M. Söderman - Karolinska Hospital, Department of Neuroradiology, Stockholm, Sweden

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 57. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie. Essen, 11.-14.05.2006. Düsseldorf, Köln: German Medical Science; 2006. DocSA.05.07

The electronic version of this article is the complete one and can be found online at:

Published: May 8, 2006

© 2006 Lippitz et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: The purpose of the study is to define the clinical and radiological long term outcome after Gamma Knife radiosurgery for AVMs located close to the brain stem, in order to optimize future selection and treatment parameters. This study is the first to describe a clinical follow-up of more than 7 years.

Methods: 42 consecutive patients with AVM in or close to the brainstem, who were treated with Gamma Knife radiosurgery at the Karolinska Hospital, Stockholm were studied retrospectively. Clinical follow-up (FU): 7.1 years (3.3-13.4). The median prescription dose was 17 Gy (2-25). The dose plans were analysed according to a dose/volume based prediction model. Clinical and radiological FU were related to predicted outcome.

Results: The obliteration rate was 47%. 19% of the patients presented with a rebleeding. The Karlsson model predicted the outcome with respect to obliteration. The number of observed complications (22%: n=8) exceeded the predicted number (n=2) considerably. 8 patients developed focal symptoms (7/8 moderate) after an average of 22 months (8-78). The established risk models did not predict the complication rate correctly. Instead, the volume of the 18 Gy isodose correlated with the risk for complication.

Conclusions: This long-term study defines the success and pitfalls for radiosurgery of brain stem AVM. The obliteration rate was lower than usually reported due to the applied low doses. A considerable number of patients suffered from rebleeding. The current data support the predictive value of mathematical models for AVM obliteration. The clinical complication rate exceeded the predicted complication rate considerably. Risk models only reflect the number of patients with complications without taking the clinical severity of the symptoms into account. With regard to the potential danger of a rebleeding and the relatively low clinical impact of the observed radiation related complications, Gamma Knife radiosurgery of cerebral AVM in the brain stem is considered to be an important treatment alternative.