NIMG-38. QUALITY OF SURGICAL DECISION MAKING FOR PATIENTS WITH A GLIOBLASTOMA IS SIMILAR BETWEEN NEURO-ONCOLOGICAL CARE TEAMS FROM THE UNITED STATES OF AMERICA AND THE NETHERLANDS

Abstract

INTRODUCTION The extent of resection is important to improve survival in patients with a glioblastoma. The neurosurgeon’s aim is to maximize the extent of resection, while preserving functional integrity. Standards to aid in patient counselling and guide surgical decision making are nevertheless lacking, hence quality of surgical care might differ between neuro-oncological care teams. In this study we present a novel volumetric method to quantify post-resection residual tumors throughout the brain for patient populations. This allows direct comparison of surgical results between care teams. METHODS All adults with first-time glioblastoma surgery in 2012-2013 in each of two Dutch and one United States tertiary referral centres for neuro-oncological care were included in this study. From each of these patient populations preoperative tumors and postoperative residual disease were segmented on MRI and registered to standard space. Brain maps of tumor and residual tumor locations were constructed for each country. Differences between these brain maps were analysed to explore patient selection and treatment variation. RESULTS This study cohort consisted of 403 patients (the Netherlands: 268; the United States: 135). Of these, 111 tumors were biopsied and 292 resected. Tumor localization maps illustrate established preferential sites for glioblastoma distributions for each cohort, indicating similar patient referral patterns, selection or recruitment. Resection probability maps demonstrate no differential residual tumor localization throughout the brain, indicating similar surgical decision making. Brain maps were reviewed by the care teams and arguments for future decision making were discussed. CONCLUSIONS Brain maps of tumor localization convey important information that can be used to compare neuro-oncological care teams in terms of patient selection. In addition, surgical decision making can be made explicit through resection probability maps. This novel volumetric approach can provide objective arguments for discussions between care teams on the quality of neurosurgical care for patients with a glioblastoma.