Artikel
Phase I/II study of intra-operative photodynamic therapy with 5-ALA in recurrent malignant gliomas
Phase-I/II-Studie zur intraoperativen photodynamischen Therapie maligner Gliome mit 5-ALA
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Veröffentlicht: | 11. April 2007 |
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Gliederung
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Objective: ALA has been explored as an intraoperative fluorescence-marker for malignant glioma surgery and has been under experimental investigation as photosensitizer. The present prospective study was designed to elucidate safety and efficacy of ALA for intraoperative photodynamic therapy of residual tumor in patients with recurrent malignant gliomas.
Methods: 21 patients (median age 46.8 years, median KPS 100), suffering recurrent malignant glioma (WHO Grad III: n=7, WHO Grade IV n=14) with tumors amenable to surgery were included. Patients were chosen if it appeared likely that residual tumor would be left unresected in eloquent brain areas. Patients were subdivided into three successive groups for treatment with escalating light doses (100, 150, 200 J/cm2 ) after fluorescence-guided surgery using 5-ALA. Laser light (635 nm, Ceramoptec Diode Laser) was applied via a fiber/microlens system. Doses were regulated by varying the duration of irradiation (500, 750, 1000 s) using constant light intensities (200 mW). Patients were monitored for adverse events, NIH stroke score, KPS, EORTC Quality of Life Score, progression-free survival, based on MR data, and overall survival.
Results: Severe adverse events (e.g. pulmonary embolism, seizures, secondary neurological deterioration) were observed in 7 patients during the observation period, but in only one patient within 7 days after surgery. No severe adverse events were considered causally related to treatment. Progression-free survival to date was 8.2 and 13.2 months using 100 and 150 J/cm2, respectively. Median progression-free survival was not yet been reached in the 200 J/cm2 group. Overall survival was 13.8 and 15.3 months (100 and 150 J/cm2; 200 J/cm2: median survival not yet reached). Function scores revealed no dose-dependent variations.
Conclusions: Intraoperative PDT of residual tumor using 5-ALA in recurrent malignant glioma was not associated with obvious mortality related to the procedure. Promising outcomes in terms of progression-free survival and overall survival suggest that this concept should be further persued.