Article
Is preoperative geometry and texture of glioblastomas prognostically relevant?
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Published: | June 9, 2017 |
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Outline
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Objective: The importance of preoperative MRI based geometric features in glioblastoma patients is currently debated in a controversial way. The goal of this study was to identify the value of distinct preoperative tumor related volumes as well as postoperative residual tumor volume and clinical and molecular parameters in predicting patient survival.
Methods: We retrospective analysed 189 patients with glioblastoma who underwent radiochemotherapy according to the stupp protocol. The MR T1-weighted post contrast and FLAIR images were segmented so as to describe the three major tumor textures: active tumor, necrosis and edema/infiltration. Preoperative and postoperative tumor volumes were calculated using the iPlan software and the methodology was verified with the Discovery software. Age, sex, performance status (KPS), duration of symptoms, infiltration of midline structures and MGMT promotor methylation status were also included in the multivariate analysis.
Results: Preoperative volumes of contrast enhancing tumor, necrosis and edema as well as the various volume ratios failed to attain any statistical significance regarding survival prognosis. In the multivariate analysis, age, infiltration of the midline structures as well as MGMT promotor methylation status were significant prognostic factors for progression-free (PFS) and overall survival (OS). Postoperative residual tumor volume and the percentage of resection was an important prognostic factor both for OS (OR=0,98, p=0,03) and for PFS (OR=0,96, p=0,02).
Conclusion: Our findings implicate that preoperative volumetric parameters lack significant role in the prognosis of glioblastoma patients. We confirmed that the extent of resection is an independent significant prognostic factor that affects both PFS and OS irrespective of the tumor volume or geometry prior to operation.