gms | German Medical Science

Objective: A safe total resection followed by adjuvant chemoradiotherapy should be the primary goal in the treatment of glioblastomas (GBMs) to enable patients the longest survival possible. Two major techniques, 5-aminolevulinic acid (5-ALA)- and intraoperative MRI (iMRI)- assisted surgery, have been shown in prospective randomized trials to significantly improve the extent of resection (EOR) and subsequently survival of patients with GBMs. Yet no direct comparison of surgical results of both techniques has been published to date.

Method: Residual tumor volumes and clinical parameters after GBM resection were analyzed for sixty-five patients after conventional surgery with and without 5-ALA and twenty-eight patients after iMRI-assisted surgery.

Results: iMRI-assisted surgery [mean residual tumor: 0.09 (0.0–7.7) cm³] significantly improved mean postoperative residual tumor-volumes compared to conventional surgery [3.1 (0.0–30.6) cm³; p=0.0009], and specifically with 5-ALA [1.965 (0.0–13.18) cm³; p=0.04] and without 5-ALA [4.7 (0–30.6) cm³; p=0.0001]. Total resections were significantly more common in iMRI-assisted surgery (64%) than in conventional (26%, p=0.0009) surgery with 5-ALA (35%, p=0.04) and without 5-ALA (14%, p=0.0003). Improvement of the EOR by using iMRI was safely achievable as peri- and postoperative morbidities were comparable between the cohorts.

Conclusions: Analysis of residual tumor volumes, total resections and neurological outcomes clearly demonstrate that iMRI is significantly superior to 5-ALA surgery for glioblastomas at comparable peri- and postoperative morbidities. Future multicenter studies with prospectively randomized patient cohorts and standardized adjuvant therapies are needed to undoubtedly confirm the benefit of using iMRI in the therapy of glioblastomas.