Measurements of heterogeneity in gliomas on computed tomography relationship to tumour grade

Abstract

To undertake a preliminary study that uses CT texture analysis (CTTA) to quantify heterogeneity in gliomas on contrast-enhanced CT and to assess the relationship between tumour heterogeneity and grade. Retrospective analysis of contrast enhanced CT images was performed in 44 patients with histologically proven cerebral glioma between 2007 and 2010. 11 tumours were low grade (Grade I = 3; Grade II, = 8) and 33 high grade (Grade III = 10, Grade IV = 23). CTTA assessment of tumour heterogeneity was performed using a proprietary software algorithm (TexRAD) that selectively filters and extracts textures at different anatomical scales between filter values 1.0 (fine detail) and 2.5 (coarse features). Heterogeneity was quantified as standard deviation (SD) with or without filtration. Tumour heterogeneity, size and attenuation were correlated with tumour grade. For each parameter, receiver operating characteristics characterised the diagnostic performance for discrimination of high grade from low grade glioma and of grade III tumours from grade IV. Further the CTTA was compared to the radiological diagnosis. Tumour heterogeneity correlated significantly with grade (SD without filtration rs = 0.664, p < 0.001, SD with coarse filtration (rs = 0.714, p < 0.001). Tumour size and attenuation showed only moderate correlations with tumour grade (rs = 0.426, p = 0.004 and rs = 0.447, p = 0.002 respectively). Coarse texture was the best discriminator between high and low grade tumours (AUC 0.832, p < 0.0001) and between grade III and grade IV gliomas (AUC = 0.878 p = 0.0001). Compared to the radiological diagnosis, CTTA further characterised the indetermined cases. By quantifying tumour heterogeneity, CTTA has the potential to provide a marker of tumour grade for patients with cerebral glioma. By differentiating between high and low grade tumours, CTTA could possibly assist clinical management.

CT texture analysis can help differentiate between malignant and benign lymph nodes in the mediastinum in patients suspected for lung cancer

“…However, a systematic bias was introduced when looking at inter-observer variance. The second reader concistently had 12 higher values than the first reader. This may reflect inclusion of nearby calcifications or vessel walls.…”

Application of Computed Tomography for Differential Diagnosis of Glioma Stoke and Simple Cerebral Hemorrhage

“…Astrocytoma, originating from astroglia, is the most commonly-encountered tumor in nervous system, usually occupying over 70% in gliomas. Uneven density, unclear edge, much annular intensity, different degrees of edema and space-occupying effect are presented in its CT signs (Gielen et al, 2013;Skogen et al, 2013). Oligodendroglioma, accounting for 5% in brain-derived tumors, frequently manifests slightly low density, calcification and mild space-occupying effect, and part of them can encounter cystic change.…”

Texture analysis of diffusion weighted imaging for the evaluation of glioma heterogeneity based on different regions of interest

“…The World Health Organization (WHO) classifies gliomas into grades I-IV, where I and II are low-grade gliomas (LGGs) and III and IV are high-grade gliomas (HGGs) (1). Determining the correct grade of the tumor is of great importance as it dictates the management and prognosis for the patient (2). HGGs are managed with radical resection and with adjuvant radiotherapy and/or chemotherapy, whereas LGGs are very slow growing and can undergo curative resection and have considerably better prognosis (3).…”

“…Mostradiologists estimate tumor classification via simple visual inspection of ADC, however, this inevitably has a lot of subjective factors. The method of texture analysis that quantifies tumor heterogeneity on routinely available images could offer a complementary tool to existing radiological practice in differentiating HGGs from LGGs (2).…”

“…However, the choice of region of interest is variable. A study performed by Skogen et al (2) only drew the area within the contrast enhanced tumor and excluded peritumoral edema for CT texture analysis in quantifying tumor heterogeneity of gliomas and showed a correlation between tumor heterogeneity and tumor grade. Skogen et al (21) delineated the solid tumor for the regions of interest (ROI), and revealed that textural features extracted on contrast-enhanced (CE) images were highly discriminant between LGG and HGG.…”