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

Minimally invasive therapy of supratentorial WHO grade II astrocytoma by interstitial radiosurgery: long-term results

Langzeitergebnisse minimal invasiver Therapie bei supratentoriellen WHO-II-Astrozytomen mittels interstitieller Radiochirurgie

Meeting Abstract

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  • corresponding author S. Grau - Neurochirurgischer Klinik, Klinikum Großhadern, Ludwig-Maximilians-Universität München
  • U. Faist - Neurologische Klinik, Albert-Ludwigs-Universität, Freiburg
  • C.B. Ostertag - Abt. für Stereotaktische Neurochirurgie, Albert-Ludwigs-Universität, Freiburg
  • F.W. Kreth - Neurochirurgischer Klinik, Klinikum Großhadern, Ludwig-Maximilians-Universität München

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. DocFR.11.09

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

Published: May 8, 2006

© 2006 Grau 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: Besides open resection and external beam radiation, interstitial radiosurgery provides a minimal invasive therapeutic approach in treating World Health Organization (WHO) Grade II astrocytoma or oligoastrocytoma. However, detailed long-term outcome data are not available for adult patients up to now. Here we show long term follow up data of 239 patients with supratentorial WHO II astrocytoma/oligoastrocytoma treated with interstitial radiosurgery.

Methods: A previously assessed cohort of 239 adult patients with circumscribed supratentorial de-novo astrocytoma (187 patients) and oligoastrocytoma (52 patients) treated with interstitial Iodine-125 (I-125) radiosurgery as primary treatment (1979-1992) was revisited for long term data. Survival, progression-free survival, functionally independent survival, post-recurrence survival and time to malignant transformation were estimated with the Kaplan Meier method. Prognostic factors were obtained from the Cox multivariate proportional hazards model.

Results: Five-, 10- and 15-year survival (progression free survival) was 56% (45%), 37% (21%) and 26% (14%), respectively (median follow-up: 10.3 years). The corresponding malignant transformation rates were 33%, 54%, and 67%. No levelling off of the Kaplan-Meier curves could be observed for any of the chosen endpoints. Age >50 years, a tumor volume >20 ml and/or a Karnofsky score ? 80 were associated with decreased survival/progression-free survival. Age >35 years and/or a tumor volume >20 ml increased the risk of malignant transformation. Prognostic factors determined subsets of patients with 10-year survival (progression-free survival) ranging from as low as 6% (1%) to as high as 55% (31%), respectively. Transient radiogenic complications occurred in 19 patients, eight patients developed a space occupying radionecrosis. No procedure related complications.

Conclusions: Long-term tumor stabilization is rare. As the outcome is mainly determined by treatment-independent factors, the minimization of any treatment-related risk must be considered essential. Thus, interstitial radiosurgery represents a minimal invasive and safe treatment option.