Long-sustaining response in a patient with non-resectable, distant recurrence of glioblastoma multiforme treated by interstitial photodynamic therapy using 5-ALA: case report.

Glioblastoma multiforme continues to be a devastating disease despite modest improvements in survival achieved at present, and there is an urgent need for innovative treatment concepts. Five-aminolevulinic acid (ALA) is a drug which induces protoporphyrin IX accumulation in malignant gliomas and has been explored for fluorescence-guided resections of these tumors. ALA is also under investigation as a photosensitizer.