Clinical Study
Delayed complications after Gamma Knife surgery for intractable epilepsy

https://doi.org/10.1016/j.jocn.2013.11.044Get rights and content

Abstract

Despite the controversy concerning the clinical usefulness of Gamma Knife surgery (GKS; Elekta AB, Stockholm, Sweden) for intractable epilepsy, this treatment modality has attracted attention due to its low invasiveness. We report the long-term outcomes of four patients, focusing particularly on the efficacy and complications of GKS. We reviewed the data of four patients with medically intractable epilepsy who underwent GKS between 1998 and 2000 at our hospital. The marginal dose to the 50% isodose line was 24 Gy in one patient and 20 Gy in the remaining three patients. Two of the four patients were treated in the right temporal lobe, one was treated in the left parietal lobe, and one was treated in the right frontal lobe. The mean follow-up was 12.5 years (range 12–14 years). One patient was seizure free (Engel class IA) 24 months after GKS, and two patients failed to show any seizure reduction (Engel class IVA). However, a clear aggravation was evident in one patient (Engel class IVC). All four patients underwent resective surgery due to radiation necrosis (RN) 7, 10, 10 and 12 years after GKS. Three patients were seizure free (Engel class IA), and one was considered to have Engel class IB status following the resective surgery. GKS treatment resulted in insufficient seizure control and carried a significant risk of RN after several years. Drawbacks such as a delay in seizure control and the risk of RN should be considered when the clinical application of this treatment is evaluated.

Introduction

Epilepsy surgery, an effective treatment for properly selected patients with intractable seizures, has achieved encouraging outcomes in the treatment of medically intractable epilepsy [1]. However, there are associated risks, including intracranial hemorrhage, infection, neurological deficits, and anesthesia complications [2]. Accordingly, the use of Gamma Knife surgery (GKS; Elekta AB, Stockholm, Sweden) for epilepsy has attracted attention as an alternative treatment option. In a recent prospective multicenter pilot trial in which two different radiosurgery doses were compared, an overall seizure remission rate of 69% was observed at the 3 year follow-up, a finding that is comparable to that reported for respective temporal lobectomy [3]. However, another report with 8 years of follow-up failed to demonstrate that GKS successfully controlled seizures in the long term [4]. Accordingly, the clinical efficacy of GKS for medically intractable epilepsy remains controversial, and its role in the treatment of medically intractable epilepsy needs to be further evaluated for efficacy and safety.

In this article, we report the long-term outcomes of four patients with intractable epilepsy who underwent GKS and required resective surgery due to radiation necrosis (RN).

Section snippets

Methods

Between 1998 and 2000, four patients underwent GKS. All four patients had medically intractable generalized tonic-clonic seizure or complex partial seizure epilepsy associated with sudden falls or other seizure types, documented by video-electroencephalography analysis and cranial MRI (Fig. 1a), and based on descriptions from family members. Histological specimens obtained during the resective surgery were reviewed to confirm the diagnosis of RN.

Seizure outcome was classified according to a

Long-term efficacy

Four male patients with a mean age of 31.6 years (range 19–39 years) underwent GKS. Two were treated in the right temporal lobe, one was treated in the left parietal lobe, and one was treated in the right frontal lobe. The characteristics of the population are listed in Table 1. The mean follow-up duration was 12.5 years (range 12–14 years). One patient was seizure-free (Patient 4, Engel class IA) 24 months after GKS, and Patient 2 and Patient 3 failed to show any seizure reduction (Engel class

Discussion

Stereotactic radiosurgery, which is commonly performed for the minimally invasive treatment of focal lesions that are otherwise hard to reach via open surgery, is becoming increasingly popular for the treatment of focal epileptic lesions [6]. Although the clinical significance of GKS for resistant-drug epilepsy is still under discussion, the treatment nonetheless attracts attention because it is less invasive than resective surgery. However, although epilepsy radiosurgery has been performed for

Conflicts of Interest/Disclosures

The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication.

Acknowledgements

This work was supported in part by the China Postdoctoral Science Foundation (20060400094), the Beijing Outstanding Talent Training Program (2009D003034000002), and the Beijing Health System Advanced Health Technology Talent Cultivation Plan (2011-3-032).

References (29)

  • P. Romanelli et al.

    Non-resective surgery and radiosurgery for treatment of drug-resistant epilepsy

    Epilepsy Res

    (2012)
  • S. Rheims et al.

    Long-term outcome of gamma-knife surgery in temporal lobe epilepsy

    Epilepsy Res

    (2008)
  • J.C. Flickinger et al.

    Estimation of complications for linear accelerator radiosurgery with the integrated logistic formula

    Int J Radiat Oncol Biol Phys

    (1990)
  • S. McClelland et al.

    Population-based analysis of morbidity and mortality following surgery for intractable temporal lobe epilepsy in the United States

    Arch Neurol

    (2011)
  • E.F. Chang et al.

    Epilepsy Radiosurgery Study Group. Predictors of efficacy after stereotactic radiosurgery for medial temporal lobe epilepsy

    Neurology

    (2010)
  • Z. Vojtech et al.

    The use of radiosurgery for the treatment of mesial temporal lobe epilepsy and long-term results

    Epilepsia

    (2009)
  • J. Engel et al.

    Outcome with respect to epileptic seizures. Surgical treatment of the epilepsies

    (1993)
  • M. Quigg et al.

    Radiosurgery for epilepsy: clinical experience and potential antiepileptic mechanisms

    Epilepsia

    (2012)
  • J. Régis et al.

    First secletive amygdalohippocampal radiosurgery for ‘mesial temporal lobe epilepsy’

    Stereotact Funct Neurosurg

    (1995)
  • F. Bartolomei et al.

    Long-term efficacy of gamma knife radiosurgery in mesial temporal lobe epilepsy

    Neurology

    (2008)
  • N.M. Barbaro et al.

    A multicenter, prospective pilot study of gamma knife radiosurgery for mesial temporal lobe epilepsy: seizure response, adverse events, and verbal memory

    Ann Neurol

    (2009)
  • T. Srikijvilaikul et al.

    Failure of gamma knife radiosurgery for mesial temporal lobe epilepsy: report of five cases

    Neurosurgery

    (2004)
  • J.C. Ganz et al.

    Radionecrosis following Gamma Knife treatment for mesial temporal lobe epilepsy

    Br J Neurosurg

    (2011)
  • J. Jagannathan et al.

    Long-term survival after gamma knife radiosurgery for primary and metastatic brain tumors

    Am J Clin Oncol

    (2004)
  • Cited by (7)

    • Epilepsy

      2022, Progress in Brain Research
      Citation Excerpt :

      It must however be mentioned that a contemporary American multicenter study found that microsurgery was slightly more effective at achieving seizure remission (Barbaro et al., 2018). It is also perhaps relevant that microsurgery has been repeatedly successful in treating GKNS MTLE patients who do not respond or who had symptomatic complications (Chen et al., 2014; Finet et al., 2010; Hoggard et al., 2008; Kawai et al., 2001; Prayson and Yoder, 2007; Rheims et al., 2008; Srikijvilaikul et al., 2004; Usami et al., 2012; Vale et al., 2012; Vojtech et al., 2009). On the basis of the information presented in the preceding paragraphs it seems quite reasonable to agree with the ISRS paper, that GKNS can produce results close to those of microsurgery.

    • Evidence on the efficacy of primary radiosurgery or stereotactic radiotherapy for drug-resistant non-neoplastic focal epilepsy in adults: A systematic review

      2018, Seizure
      Citation Excerpt :

      The first changes on MRI scans were observed after 6 months whereas they also occurred 10 years following RT [28]. Hyperintense regions on the T2-weighted MRI scans were first detected after 6 months (peak 9–24 months) and tended to disappear after a few years, whereas four studies described cystic lesions several years after treatment which needed resection [11–14,27,29,30,32,34,35]. Overall, 20% (34 patients; range 7–100%) of the patients in nine of the 16 studies underwent subsequent surgery [12–14,26,27,29,28,32,34,35].

    • Radiosurgery for epilepsy: Systematic review and International Stereotactic Radiosurgery Society (ISRS) practice guideline

      2017, Epilepsy Research
      Citation Excerpt :

      Another report Hensley-Judge et al. (2013) found 62.5% prevalence of superior quadrantanopia, comparable to anterior temporal lobectomy. From retrospective case series, reported adverse effects include injury or death due to seizures (accidents or sudden unexpected death in epilepsy (SUDEP) (Srikijvilaikul et al., 2004)) while awaiting therapeutic effect of RS, and late complications of radionecrosis (Chen et al., 2014; Usami et al., 2012; Vojtech et al., 2009). Low dose LINAC radiosurgery in 7 patients was associated with significant side effects as well as poor seizure outcome, with 2/7 patients suffering permanent neurological complications (Liang et al., 2010).

    • Anterior temporal lobectomy compared with laser thermal hippocampectomy for mesial temporal epilepsy: A threshold analysis study

      2015, Epilepsy Research
      Citation Excerpt :

      Additionally, the preliminary data suggest that LTH offers more immediate seizure-freedom in contrast to Gamma Knife. More importantly, however, is that although noninvasive, Gamma Knife has resulted in an unacceptable rate of delayed radiation necrosis, and in one series, all patients required an open intervention for treatment of symptomatic radiation necrosis (Chen et al., 2014; Usami et al., 2012). For patients, a less invasive procedure with shorter recovery time to improve their epilepsy is an intuitively preferable choice.

    • Surgical strategies for pediatric epilepsy

      2016, Translational Pediatrics
    View all citing articles on Scopus
    View full text