gms | German Medical Science

Objective: Ventricular wall or ependymal fluorescence during 5-ALA guided microsurgical resection of malignant glioma is a common phenomenon. However, its pathophysiology and clinical importance are largely unknown. Objective of this study is to compare our centers’ experiences with existing evidence.

Methods: Literature search on MEDLINE, EMBASE and WEB OF SCIENCE was performed using the following headings and Boolean operators: (ependymal fluorescence AND ventricular wall fluorescence) AND (5-ALA AND five aminolevulinic acid). Abstracts were analyzed according to PRISMA protocol by both authors independently. Our clinical series of 21 patients with ependymal fluorescence is reported according to PROCESS guidelines.

Results: Previous studies have shown that fluorescence of the ventricular wall is not always indicative of histopathological tumor invasion. Fluorescing tumor may well extend into the subventricular zone and therefore cause ventricular wall fluorescence. However, according to our series of 21 cases, remote fluorescence distant to compact fluorescing tumor is sometimes seen in clinical practice, especially in recurrent malignant glioma previously having undergone cytotoxic therapies.

Conclusion: The phenomenon of ventricular wall fluorescence in 5-ALA derived fluorescence-guided resection of malignant glioma is poorly understood. A larger scale prospective sampling study with molecular analyses is currently ongoing and will hopefully provide further insight into pathophysiology of ependymal fluorescence.