gms | German Medical Science

Objective: Glioblastoma (GBM) is the most common brain tumor of the adult population. Standard management consists of microsurgical resection, concomitant radio chemotherapy followed by adjuvant chemotherapy. Maximal resection has been demonstrated to provide the best outcome. The foundation of a specialized neuro-oncology care center following the paradigm maximal resection with minimal morbidity requires the implementation of a large technical portfolio including functional imaging, awake craniotomy with direct cortical and subcortical stimulation, intraoperative neuromonitoring and fluorescence supported resection. We wanted to address the question whether the innovation in the neurosurgical management have resulted in a larger extent of resection and ultimately improved patients outcome

Methods: A cohort of 149 patients (mean age 61.8 years; female male ratio 67/82) treated surgically for newly diagnosed GBM were included. Neurological and functional independence status were measured by the medical research neurological performance status (NPS) and the Karnofsky performance score (KPS) respectively. Extent of resection was volumetrically quantified utilizing Brain Lab iPlan Cranial software version 3 BrainLAB AG Germany. Based on the treatment timepoint, patients were stratified into a subcohort before and after implementation of the above mentioned technical improvements. Subsequently, the surgical treatment pattern and the resulting progression free (PFS) and overall survival (OS) was evaluated

Results: Both KPS and NPS had significantly improved postsurgically. Relevant confounding factors for PFS and OS in the entire patient population were age beyond 65 years (p = 0.001) and the MGMT promoter methylation status (p = 0.005). Patients with a volumetrically determined complete resection had a significantly better PFS (8.7 vs 7.8 months p = 0.041) and OS (18.4 vs 14.5 months p = 0.005) compared to incompletely resected patients. The frequency of transient or permanent postoperative neurological deficits was not higher after complete resection compared to subtotal resection. The frequency of complete resection significantly improved in the timespan after the implementation of technical improvements (34.8% to 68.2% p = 0.007). Accordingly the patient cohort being treated utilizing the improved technical potential showed a significantly better PFS (8.9 vs 7.6 months p = 0.002) and OS (16.8 vs 13.1 months p = 0.032). Multivariat Cox regression analysis revealed age, MGMT promoter status, complete resection and treatment time span as independent prognostic factors for PFS and OS

Conclusion: Our data demonstrate that the frequency of complete resection in GBM patients is improved upon a series of technical developments in the neurosurgical management. This results in a significantly better outcome without the risk of increased surgery related morbidity