gms | German Medical Science

Objective: In a randomized trial the use of an intraoperative MRI led to improved rates of complete tumor removal. In this study, complete tumor removal was associated with longer progression-free survival. However, overall survival (OS) was not addressed in the primary analysis.

Method: We performed a secondary analysis of survival data of patients with primary glioblastomas who participated in a clinical trial comparing conventional with intraoperative MRI guided microsurgery that was published before. All patients underwent tumor removal between Oct 2007 and Jul 2010. Adjuvant therapy was administered according to interdisciplinary board decision and patient preference.

Results: We analyzed survival data of 37 patients with a median age of 56 years (range: 30–76). Median OS was 20.1 months. While the use of iMRI itself did not affect outcome (p=0.40), patients with a radiologically complete resection had longer OS than patients with residual contrast enhancing tumor (26.0 vs. 13.4 months, p<0.05). There was a trend for clinical status influencing OS: patients with KPS≥90 had an OS of 24.1 months, while it was only 13.4 for patients with KPS≤80 (p=0.09). Patient age was not a statistically significant factor concerning OS (p=0.48). On multivariate analysis, completeness of resection, in contrast to KPS, remained statistically significant (p<0.05).

Conclusions: Radiologically complete removal of contrast enhancing tissue is an important prognostic factor for patients with primary GBM. Use of intraoperative MRI helps to achieve a higher rate of complete resections and thus directly impacts patient outcome.