| 1. |
- Bø, Hans Kristian, et al.
(författare)
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Intra-rater variability in low-grade glioma segmentation.
- 2017
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Ingår i: Journal of neuro-oncology. - : Springer Science and Business Media LLC. - 1573-7373 .- 0167-594X. ; 131:2, s. 393-402
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Tidskriftsartikel (refereegranskat)abstract
- Assessment of size and growth are key radiological factors in low-grade gliomas (LGGs), both for prognostication and treatment evaluation, but the reliability of LGG-segmentation is scarcely studied. With a diffuse and invasive growth pattern, usually without contrast enhancement, these tumors can be difficult to delineate. The aim of this study was to investigate the intra-observer variability in LGG-segmentation for a radiologist without prior segmentation experience. Pre-operative 3D FLAIR images of 23 LGGs were segmented three times in the software 3D Slicer. Tumor volumes were calculated, together with the absolute and relative difference between the segmentations. To quantify the intra-rater variability, we used the Jaccard coefficient comparing both two (J2) and three (J3) segmentations as well as the Hausdorff Distance (HD). The variability measured with J2 improved significantly between the two last segmentations compared to the two first, going from 0.87 to 0.90 (p=0.04). Between the last two segmentations, larger tumors showed a tendency towards smaller relative volume difference (p=0.07), while tumors with well-defined borders had significantly less variability measured with both J2 (p=0.04) and HD (p<0.01). We found no significant relationship between variability and histological sub-types or Apparent Diffusion Coefficients (ADC). We found that the intra-rater variability can be considerable in serial LGG-segmentation, but the variability seems to decrease with experience and higher grade of border conspicuity. Our findings highlight that some criteria defining tumor borders and progression in 3D volumetric segmentation is needed, if moving from 2D to 3D assessment of size and growth of LGGs.
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| 2. |
- Bø, Hans Kristian, et al.
(författare)
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Intraoperative 3D ultrasound-guided resection of diffuse low-grade gliomas: radiological and clinical results.
- 2020
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Ingår i: Journal of neurosurgery. - 1933-0693. ; 132:2, s. 518-529
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVEExtent of resection (EOR) and residual tumor volume are linked to prognosis in low-grade glioma (LGG) and there are various methods for facilitating safe maximal resection in such patients. In this prospective study the authors assess radiological and clinical results in consecutive patients with LGG treated with 3D ultrasound (US)-guided resection under general anesthesia.METHODSConsecutive LGGs undergoing primary surgery guided with 3D US between 2008 and 2015 were included. All LGGs were classified according to the WHO 2016 classification system. Pre- and postoperative volumetric assessments were performed, and volumetric results were linked to overall and malignant-free survival. Pre- and postoperative health-related quality of life (HRQoL) was evaluated.RESULTSForty-seven consecutive patients were included. Twenty LGGs (43%) were isocitrate dehydrogenase (IDH)-mutated, 7 (14%) were IDH wild-type, 19 (40%) had both IDH mutation and 1p/19q codeletion, and 1 had IDH mutation and inconclusive 1p/19q status. Median resection grade was 93.4%, with gross-total resection achieved in 14 patients (30%). An additional 24 patients (51%) had small tumor remnants < 10 ml. A more conspicuous tumor border (p = 0.02) and lower University of California San Francisco prognostic score (p = 0.01) were associated with less remnant tumor tissue, and overall survival was significantly better with remnants < 10 ml (p = 0.03). HRQoL was maintained or improved in 86% of patients at 1 month. In both cases with severe permanent deficits, relevant ischemia was present on diffusion-weighted postoperative MRI.CONCLUSIONSThree-dimensional US-guided LGG resections under general anesthesia are safe and HRQoL is preserved in most patients. Effectiveness in terms of EOR appears to be consistent with published studies using other advanced neurosurgical tools. Avoiding intraoperative vascular injury is a key factor for achieving good functional outcome.
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| 3. |
- Fyllingen, Even Hovig, et al.
(författare)
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Survival of glioblastoma in relation to tumor location: a statistical tumor atlas of a population-based cohort.
- 2021
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Ingår i: Acta neurochirurgica. - : Springer Science and Business Media LLC. - 0942-0940 .- 0001-6268. ; 163, s. 1895-1905
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies on the effect of tumor location on overall survival in glioblastoma have found conflicting results. Based on statistical maps, we sought to explore the effect of tumor location on overall survival in a population-based cohort of patients with glioblastoma and IDH wild-type astrocytoma WHO grade II-III with radiological necrosis.Patients were divided into three groups based on overall survival: < 6 months, 6-24 months, and > 24 months. Statistical maps exploring differences in tumor location between these three groups were calculated from pre-treatment magnetic resonance imaging scans. Based on the results, multivariable Cox regression analyses were performed to explore the possible independent effect of centrally located tumors compared to known prognostic factors by use of distance from center of the third ventricle to contrast-enhancing tumor border in centimeters as a continuous variable.A total of 215 patients were included in the statistical maps. Central tumor location (corpus callosum, basal ganglia) was associated with overall survival < 6 months. There was also a reduced overall survival in patients with tumors in the left temporal lobe pole. Tumors in the dorsomedial right temporal lobe and the white matter region involving the left anterior paracentral gyrus/dorsal supplementary motor area/medial precentral gyrus were associated with overall survival > 24 months. Increased distance from center of the third ventricle to contrast-enhancing tumor border was a positive prognostic factor for survival in elderly patients, but less so in younger patients.Central tumor location was associated with worse prognosis. Distance from center of the third ventricle to contrast-enhancing tumor border may be a pragmatic prognostic factor in elderly patients.
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| 4. |
- Jakola, Asgeir Store, et al.
(författare)
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Quantitative texture analysis in the prediction of IDH status in low-grade gliomas.
- 2018
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Ingår i: Clinical neurology and neurosurgery. - : Elsevier BV. - 1872-6968 .- 0303-8467. ; 164, s. 114-120
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Tidskriftsartikel (refereegranskat)abstract
- Molecular markers provide valuable information about treatment response and prognosis in patients with low-grade gliomas (LGG). In order to make this important information available prior to surgery the aim of this study was to explore if molecular status in LGG can be discriminated by preoperative magnetic resonance imaging (MRI).All patients with histopathologically confirmed LGG with available molecular status who had undergone a preoperative standard clinical MRI protocol using a 3T Siemens Skyra scanner during 2008-2015 were retrospectively identified. Based on Haralick texture parameters and the segmented LGG FLAIR volume we explored if it was possible to predict molecular status.In total 25 patients (nine women, average age 44) fulfilled the inclusion parameters. The textural parameter homogeneity could discriminate between LGG patients with IDH mutation (0.12, IQR 0.10-0.15) and IDH wild type (0.07, IQR 0.06-0.09, p=0.005). None of the other four analyzed texture parameters (energy, entropy, correlation and inertia) were associated with molecular status. Using ROC curves, the area under curve for predicting IDH mutation was 0.905 for homogeneity, 0.840 for tumor volume and 0.940 for the combined parameters of tumor volume and homogeneity. We could not predict molecular status using the four other chosen texture parameters (energy, entropy, correlation and inertia). Further, we could not separate LGG with IDH mutation with or without 1p19q codeletion.In this preliminary study using Haralick texture parameters based on preoperative clinical FLAIR sequence, the homogeneity parameter could separate IDH mutated LGG from IDH wild type LGG. Combined with tumor volume, these diagnostic properties seem promising.
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| 5. |
- Munkvold, Bodil Karoline Ravn, et al.
(författare)
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Tumor Volume Assessment in Low-Grade Gliomas: A Comparison of Preoperative Magnetic Resonance Imaging to Coregistered Intraoperative 3-Dimensional Ultrasound Recordings.
- 2018
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Ingår i: Neurosurgery. - : Ovid Technologies (Wolters Kluwer Health). - 1524-4040 .- 0148-396X. ; 83:2, s. 288-296
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Tidskriftsartikel (refereegranskat)abstract
- Image guidance based on magnetic resonance imaging (MRI) and/or ultrasound (US) is widely used to aid decision making in glioma surgery, but tumor delineation based on these 2 modalities does not always correspond.To analyze volumes of diffuse low-grade gliomas (LGGs) based on preoperative 3-D FLAIR MRIs compared to intraoperative 3-D US image recordings to quantitatively assess potential discrepancies between the 2 imaging modalities.Twenty-three patients with supratentorial WHO grade II gliomas undergoing primary surgery guided by neuronavigation based on preoperative FLAIR MRI and navigated 3-D US were included. Manual volume segmentation was performed twice in 3-D Slicer version 4.0.0 to assess intrarater variabilities and compare modalities with regard to tumor volume. Factors possibly related to correspondence between MRI and US were also explored.In 20 out of 23 patients (87%), the LGG tumor volume segmented from intraoperative US data was smaller than the tumor volume segmented from the preoperative 3-D FLAIR MRI. The median difference between MRI and US volumes was 7.4 mL (range: -4.9-58.7 mL, P < .001) with US LGG volumes corresponding to a median of 74% (range: 42%-183%) of the MRI LGG volumes. However, there was considerable intraobserver variability for US volumes. The correspondence between MRI and US data was higher for astrocytomas (92%).The tumor volumes of LGGs segmented from intraoperative US images were most often smaller than the tumor volumes segmented from preoperative MRIs. There was a much better match between the 2 modalities in astrocytomas.
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| 6. |
- Skjulsvik, Anne Jarstein, et al.
(författare)
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Is the anatomical distribution of low-grade gliomas linked to regions of gliogenesis?
- 2020
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Ingår i: Journal of neuro-oncology. - : Springer Science and Business Media LLC. - 1573-7373 .- 0167-594X. ; 147, s. 147-157
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Tidskriftsartikel (refereegranskat)abstract
- According to the stem cell theory, two neurogenic niches in the adult human brain may harbor cells that initiate the formation of gliomas: The larger subventricular zone (SVZ) and the subgranular zone (SGZ) in the hippocampus. We wanted to explore whether defining molecular markers in low-grade gliomas (LGG; WHO grade II) are related to distance to the neurogenic niches.Patients treated at two Norwegian university hospitals with population-based referral were included. Eligible patients had histopathological verified supratentorial low-grade glioma. IDH mutational status and 1p19q co-deletion status was retrospectively assessed. 159 patients were included, and semi-automatic tumor segmentation was done from pre-treatment T2-weighted (T2W) or Fluid-Attenuated Inversion Recovery (FLAIR) images. 3D maps showing the anatomical distribution of the tumors were then created for each of the three molecular subtypes (IDH mutated/1p19q co-deleted, IDH mutated and IDH wild-type). Both distance from tumor center and tumor border to the neurogenic niches were recorded.In this population-based cohort of previously untreated low-grade gliomas, we found that low-grade gliomas are more often found closer to the SVZ than the SGZ, but IDH wild-type tumors are more often found near SGZ.Our study suggests that the stem cell origin of IDH wild-type and IDH mutated low-grade gliomas may be different.
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| 7. |
- Stensjøen, Anne Line, et al.
(författare)
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Does Pretreatment Tumor Growth Hold Prognostic Information for Patients with Glioblastoma?
- 2017
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Ingår i: World neurosurgery. - : Elsevier BV. - 1878-8769 .- 1878-8750. ; 101
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Tidskriftsartikel (refereegranskat)abstract
- Glioblastomas are highly aggressive and heterogeneous tumors, both in terms of patient outcome and molecular profile. Magnetic resonance imaging of tumor growth could potentially reveal new insights about tumor biology noninvasively. The aim of this exploratory retrospective study was to investigate the prognostic potential of pretreatment growth rate of glioblastomas, after controlling for known prognostic factors.A growth model derived from clinical pretreatment postcontrast T1-weighted magnetic resonance imaging images was used to divide 106 glioblastoma patients into 2 groups. The "faster growth" group had tumors growing faster than expected based on their volume at diagnosis, whereas the "slower growth" group had tumors growing slower than expected. Associations between tumor growth and survival were examined by the use of multivariable Cox regression and logistic regression.None of the known prognostic factors were significantly associated with tumor growth. An extended multivariable Cox model showed that during the first 12 months of follow-up, there was no significant difference in survival between faster and slower growing tumors. Beyond 12 months' follow-up, however, there was a significant, independent survival benefit in having a tumor with slower pretreatment growth. In a multiple logistic regression model including patients receiving both radiotherapy and chemotherapy (n= 82), slower pre-treatment growth of the tumor was shown to be a significant predictor of 2-year survival (odds ratio 4.4).Pretreatment glioblastoma growth harbors prognostic information. Patients with slower growing tumors have higher odds of survival beyond 2 years, adjusted for other prognostic factors.
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