title: Automatic estimation of extent of resection and residual tumor volume of patients with glioblastoma.
abstract: OBJECTIVE In the treatment of glioblastoma, residual tumor burden is the only prognostic factor that can be actively influenced by therapy. Therefore, an accurate, reproducible, and objective measurement of residual tumor burden is necessary. This study aimed to evaluate the use of a fully automatic segmentation method-brain tumor image analysis (BraTumIA)-for estimating the extent of resection (EOR) and residual tumor volume (RTV) of contrast-enhancing tumor after surgery. METHODS The imaging data of 19 patients who underwent primary resection of histologically confirmed supratentorial glioblastoma were retrospectively reviewed. Contrast-enhancing tumors apparent on structural preoperative and immediate postoperative MR imaging in this patient cohort were segmented by 4 different raters and the automatic segmentation BraTumIA software. The manual and automatic results were quantitatively compared. RESULTS First, the interrater variabilities in the estimates of EOR and RTV were assessed for all human raters. Interrater agreement in terms of the coefficient of concordance (W) was higher for RTV (W = 0.812; p < 0.001) than for EOR (W = 0.775; p < 0.001). Second, the volumetric estimates of BraTumIA for all 19 patients were compared with the estimates of the human raters, which showed that for both EOR (W = 0.713; p < 0.001) and RTV (W = 0.693; p < 0.001) the estimates of BraTumIA were generally located close to or between the estimates of the human raters. No statistically significant differences were detected between the manual and automatic estimates. BraTumIA showed a tendency to overestimate contrast-enhancing tumors, leading to moderate agreement with expert raters with respect to the literature-based, survival-relevant threshold values for EOR. CONCLUSIONS BraTumIA can generate volumetric estimates of EOR and RTV, in a fully automatic fashion, which are comparable to the estimates of human experts. However, automated analysis showed a tendency to overestimate the volume of a contrast-enhancing tumor, whereas manual analysis is prone to subjectivity, thereby causing considerable interrater variability.
authors.affiliation: Institute for Surgical Technology & Biomechanics, University of Bern.
authors.forename: Raphael
authors.initials: R
authors.lastname: Meier
authors.affiliation: Support Center for Advanced Neuroimaging, Institute for Diagnostic and Interventional Neuroradiology, University Hospital Inselspital and University of Bern; and.|Department of Neurosurgery, University Hospital Inselspital and University of Bern, Switzerland.
authors.forename: Nicole
authors.initials: N
authors.lastname: Porz
authors.affiliation: Support Center for Advanced Neuroimaging, Institute for Diagnostic and Interventional Neuroradiology, University Hospital Inselspital and University of Bern; and.
authors.forename: Urspeter
authors.initials: U
authors.lastname: Knecht
authors.affiliation: Support Center for Advanced Neuroimaging, Institute for Diagnostic and Interventional Neuroradiology, University Hospital Inselspital and University of Bern; and.
authors.forename: Tina
authors.initials: T
authors.lastname: Loosli
authors.affiliation: Department of Neurosurgery, University Hospital Inselspital and University of Bern, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Schucht
authors.affiliation: Department of Neurosurgery, University Hospital Inselspital and University of Bern, Switzerland.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Beck
authors.affiliation: Support Center for Advanced Neuroimaging, Institute for Diagnostic and Interventional Neuroradiology, University Hospital Inselspital and University of Bern; and.
authors.forename: Johannes
authors.initials: J
authors.lastname: Slotboom
authors.affiliation: Support Center for Advanced Neuroimaging, Institute for Diagnostic and Interventional Neuroradiology, University Hospital Inselspital and University of Bern; and.
authors.forename: Roland
authors.initials: R
authors.lastname: Wiest
authors.affiliation: Institute for Surgical Technology & Biomechanics, University of Bern.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Reyes
mesh_terms: D005909:Glioblastoma / Q000473:pathology* / Q000601:surgery*; D006801:Humans; D018365:Neoplasm, Residual / Q000473:pathology; D019635:Neurosurgical Procedures / Q000379:methods; D012189:Retrospective Studies; D015173:Supratentorial Neoplasms / Q000473:pathology* / Q000601:surgery*; D047368:Tumor Burden
keywords: BraTumIA; BraTumIA = brain tumor image analysis; CET = contrast-enhancing tumor; CRET = complete resection of the enhancing tumor; EOR = extent of resection; MPR = multiplanar reconstruction; PRET = partial resection of the enhancing tumor; RTV = residual tumor volume; T1w = T1-weighted; T2w = T2-weighted; W = Kendall's coefficient of concordance; automatic tumor volumetry; extent of resection; glioblastoma; oncology; residual tumor volume