13 July 2009 ALA-mediated fluorescence-guided resection (FGR) and PDT of glioma
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Proceedings Volume 7380, Photodynamic Therapy: Back to the Future; 73801D (2009) https://doi.org/10.1117/12.822962
Event: 12th World Congress of the International Photodynamic Association, 2009, Seattle, Washington, United States
Abstract
A summary of clinical trials employing photodynamic diagnosis (PDD) and photodynamic therapy (PDT) for the diagnosis and treatment of brain malignancies is presented. Intra-cavity PDT has been performed within the surgical cavity following FGR, employing oral administration of 5-aminolevulinic acid (5-ALA), either targeting fluorescing tissue regions that were not removed during FGR due to safety reasons (referred to as focal PDT, n=20) or illuminating the entire resection cavity (referred to as integral PDT, n=9). Both approaches proved technically feasible and safe. Spectroscopic measurements performed pre-, during and post-PDT revealed Protoporphyrin IX (PpIX)-photobleaching of more than 95% after the delivery of 200 J/cm2. This light dose did not induce any side effects. Furthermore, interstitial PDT (iPDT) has been employed within one feasibility trial (n=10) and one Phase I/II trial (n=15). Here, three to six cylindrical light diffusors (20-30 mm length, 200 mW/cm, 720 J/cm) were positioned within the target tissue under stereotactic guidance. Pre-treatment planning was performed with the intent to target the entire tumour volume with a sufficient light dose while also minimising the risk of any light-induced temperature increase. For the feasibility trial patients with small, recurrent gliomas were included, resulting in a median survival of 15 months as well as some unexpected longterm survivals (up to 5 years). The Phase I/II trial employed the same clinical procedures. Here, the 12-month survival was 35% and the median progression-free survival was 6 months. In summary, stereotactic iPDT in combination with treatment-planning could be shown to be a safe and feasible treatment modality. These trials are presently being extended to also include on-line monitoring of PpIX fluorescence and photobleaching kinetics. Preliminary data has revealed dramatically different PpIX levels and photobleaching kinetics. Such data could possibly be employed for realtime treatment monitoring and as an early prognostic marker for the PDT response.
© (2009) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ann Johansson, Ann Johansson, Herbert Stepp, Herbert Stepp, Tobias Beck, Tobias Beck, Wolfgang Beyer, Wolfgang Beyer, Thomas Pongratz, Thomas Pongratz, Ronald Sroka, Ronald Sroka, Thomas Meinel, Thomas Meinel, Walter Stummer, Walter Stummer, Friedrich-Wilhelm Kreth, Friedrich-Wilhelm Kreth, Jörg-Christian Tonn, Jörg-Christian Tonn, Reinhold Baumgartner, Reinhold Baumgartner, } "ALA-mediated fluorescence-guided resection (FGR) and PDT of glioma", Proc. SPIE 7380, Photodynamic Therapy: Back to the Future, 73801D (13 July 2009); doi: 10.1117/12.822962; https://doi.org/10.1117/12.822962
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