gms | German Medical Science

58. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

26. bis 29.04.2007, Leipzig

Stereotactic interstitial photodynamic therapy of circumscribed malignant gliomas using 5-aminolevulinic acid (5-ALA): clinical results of a pilot study

Stereotaktische interstitielle photodynamische Therapie von zirkumskripten malignen Gliomen mit 5-aminolaevulinic acid (5-ALA): Klinische Ergebnisse einer Pilotstudie

Meeting Abstract

  • corresponding author J.H. Mehrkens - Neurochirurgische Universitätsklinik, Ludwig-Maximilians-Universität München
  • T. Beck - Laserforschungs-Labor, Klinikum Großhadern, Ludwig-Maximilians-Universität München
  • W. Stummer - Neurochirurgische Universitätsklinik, Heinrich-Heine-Universität Düsseldorf
  • R. Baumgartner - Laserforschungs-Labor, Klinikum Großhadern, Ludwig-Maximilians-Universität München
  • J.-C. Tonn - Neurochirurgische Universitätsklinik, Ludwig-Maximilians-Universität München
  • F. W. Kreth - Neurochirurgische Universitätsklinik, Ludwig-Maximilians-Universität München

Deutsche Gesellschaft für Neurochirurgie. 58. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC). Leipzig, 26.-29.04.2007. Düsseldorf: German Medical Science GMS Publishing House; 2007. DocFR.04.09

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dgnc2007/07dgnc093.shtml

Published: April 11, 2007

© 2007 Mehrkens et al.
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Outline

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Objective: Photodynamic therapy (PDT) might have the potential to improve local tumour control in selected patients. However, uncertainties concerning dosimetry and photosensitizer (PS)-distribution as well as therapy-related side-effects have limited the clinical impact of PDT in brain-tumors in the past. The present pilot-study was performed 1. to establish the concept of stereotactic interstitial PDT (iPDT) using 5-ALA as PS in a clinical setting and 2. to evaluate its clinical impact.

Methods: iPDT was considered to be indicated for patients with a minimum Karnofsky Performance Status (KPS) of 70 with a “circumscribed” deep seated/eloquently located recurrence of a malignant glioma after prior multimodal therapy with a maximum diameter of 2.5 cm. All operations were performed under general anaesthesia. Patients received 20mg/Kg 5-ALA 1 h pre-operatively. After tumour-histology had been verified by stereotactic serial biopsy, 3D-multimodal-treatmentplanning (CT, MRT, FET-PET) followed by stereotactic implantation (3 mm burrhole, parallel electrode placement) of up to 6 laser-probes was performed. Irradiation time was 60 min (Ceralas PDT Diode Laser: wavelength 633nm, power 200mW/cm (biolitec AG, Jena, Germany)). Follow-up MRI was performed at 24 h, 4 weeks and than in 3-month-intervals post-operatively. Reference point was date of iPDT.

Results: Between October 2002 and June 2004 13 adult patients (mean age 51, range 31-69 years, 5 female/8 male, mean tumour volume 7.9 ml) were included. The applied volume-dose was in the range of 1000 - 1500 J/cm3. Early MRI follow-up showed a complete resolution of the contrast-enhanced lesion in 9 patients and a partial response in the other 4. No enhanced treatment-induced brain oedema was observed. There was a transient treatment related morbidity (increased hemiparesis) in 2 patients. Median follow-up was 13 months. Median survival was 13 months (range 4-49 months). The 1-year-survival rate was 54% (2 patients still alive at last follow-up).

Conclusions: Clinical outcome showed a huge variety with 4 long-term survivors (>24 months). The obviously present therapeutic effect cannot only be ascribed to apoptosis or necrosis of tumour-cells induced by iPDT alone, but also to other factors like the activation of the immune system. A further (prospective) clinical evaluation is currently subject of an ongoing Phase II study at our institution.