gms | German Medical Science

Objective: Surgical cytoreduction represents the first step in the treatment of glioblastomas (GBM), one of the most malignant tumor entities. Safe and complete tumor resection is mandatory in increasing the effectiveness of adjuvant therapy to prolong overall survival time. However, this remains hampered by the lack of clear visual discrimination between distinct tumor occupied zones and tumor cell free areas. The novel dual intraoperative visualization approach (DiVA) allows unambiguous differentiation between tumor zones, thus enabling tailored supramarginal surgery. We investigated whether this technique involving selective resection crossing tumor zones leads to improved clinical outcome in GBM patients.

Method: 115 patients with histologically confirmed GBM were included in the study. 85 patients were operated according to current best-practice in glioma surgery with intraoperative MRI alone and 30 patients in accordance with the DiVA protocol. Complete resection according to MRI criteria was achieved in all 115 patients. The preoperative condition of the patients as well as 3 months following surgery was assessed through the Karnofsky Index.

Results: The control group showed a median life expectancy of 14 months, reflecting the current standard of care and outcome for GBM patients. In contrast, patients treated via DiVA displayed significant increase in median survival time to 18.5 months (Log-rank p-value: 0.0001; Gehan-Breslow-Wilcoxon p-value: 0.0048). Hazard ratio was 2.343 with 95% CI at 1.530 to 3.590. This extension of life expectancy did not come at the cost of neurological deterioration.

Conclusions: We show for the first time that selective trans-zonal surgery according to DiVA as a refinement to standard supramarginal surgery unequivocally leads to a significant prolongation of overall survival time in GBM patients. An attendant increase in postoperative morbidity in comparison to well-established neurooncological gold-standard treatment procedures is not detectable.