Aminolevulinic acid hydrochloride is an intermediate in heme biosynthesis in the body and the universal precursor of tetrapyrroles.
5-Aminolevulinic acid is a non-fluorescent prodrug that leads to intracellular accumulation of fluorescent porphyrins in malignant gliomas-a finding that is under investigation for intraoperative identification and resection of these tumors. Median follow-up was 35.4 months (95% CI 1.0-56.7). A contrast-enhancing tumor was resected completely in 90 (65%) of 139 patients assigned 5-aminolevulinic acid compared with 47 (36%) of 131 assigned white light (the difference between groups 29% [95% CI 17-40], p<0.0001). Patients allocated 5-aminolevulinic acid had higher 6-month progression-free survival than did those allocated white light (41.0% [32.8-49.2] vs 21.1% [14.0-28.2]; difference between groups 19.9% [9.1-30.7], p=0.0003, Z test) . 5-ALA alone proved to be insufficient in attaining gross total resection without the danger of incurring postoperative neurological deterioration. Furthermore, in the case of functional grade III gliomas, iMRI in combination with functional neuronavigation was significantly superior to the 5-ALA resection technique .