Background: The clinical efficacy of 5-aminolevulinic acid (5-ALA) for fluorescence-guided surgery of malignant gliomas is evident from several studies; however, as post-operative elevations of liver enzymes have been seen, there is a potential risk of liver damage upon administration. The aim of the present study was to assess the potential risk of liver damage and investigate liver enzyme reactions of patients going through 5-ALA-guided operations to improve the monitoring of their operations.
Methods: A retrospective study of all patients undergoing 5-ALA-guided surgery during a 2-year period (September 2012-September 2014) at the University Hospital of Copenhagen, Rigshospitalet, was conducted. All patients received a pre-operative dose of 20 mg/kg bodyweight 5-ALA. The pre- and post-operative enzyme levels of alanine aminotransferase, aspartate aminotransferase, gamma glutamyltransferase and amylase of both men and women, respectively, were evaluated.
Results: Ninety-nine adults met the inclusion criteria. Fifty patients had one or multiple temporary post-operative elevations of their liver enzymes. The mean post-operative values were not increased, except for a brief elevation of gamma-glutamyltransferase levels in women. No registrations of liver impairment or clinical signs of liver failure were observed.
Conclusions: The findings suggest that the administration of 5-ALA or the combined effect of 5-ALA, anaesthesia and tumour resection can cause a mild and reversible elevation in liver enzymes. It therefore appears safe to change the regime of monitoring. Routine blood samples are thus abolished, though caution remains necessary in patients with known liver impairment.
Keywords: 5-ALA; ALAT; Glioma; Liver damage; Liver enzymes.