Perfusion MRI-Based Fractional Tumor Burden Differentiates between Tumor and Treatment Effect in Recurrent Glioblastomas and Informs Clinical Decision-Making

Fellows’ Journal Club

Forty-seven patients with high-grade gliomas (primarily glioblastoma) with recurrent contrast-enhancing lesions on DSC-MR imaging were retrospectively evaluated after surgical sampling. Histopathologic examination defined treatment effect versus tumor. Normalized relative CBV thresholds of 1.0 and 1.75 were used to define low, intermediate, and high fractional tumor burden classes in each histopathologically defined group. Performance was assessed with an area under the receiver operating characteristic curve. Mean low fractional tumor burden, high fractional tumor burden, and relative CBV of the contrast-enhancing volume were significantly different between treatment effect and tumor with tumor having significantly higher fractional tumor burden and relative CBV and lower fractional tumor burden. High fractional tumor burden and low fractional tumor burden define fractions of the contrast-enhancing lesion volume with high and low blood volume, respectively, and can differentiate treatment effect from tumor in recurrent glioblastomas. Fractional tumor burden maps can also help to inform clinical decision-making.

Abstract

Figure 1 from Iv et al
Representative examples of treatment effect (upper row) and recurrent tumor (lower row) in 2 patients with previously resected and irradiated glioblastomas. Contrast-enhancing lesions on postcontrast T1-weighted (A and E) and ΔT1 (B and F) images. Output FTB maps superimposed on the contrast-enhanced T1-weighted images (C and G). Blue represents areas of low blood volume (FTBlow), and red represents areas of high blood volume (FTBhigh). Histograms (D and H) show all voxels of the contrast-enhancing volume classified into the respective FTBlow, FTBmid (yellow), and FTBhigh classes, which is based on the rCBV thresholds of 1.0 and 1.75.

BACKGROUND AND PURPOSE

Fractional tumor burden better correlates with histologic tumor volume fraction in treated glioblastoma than other perfusion metrics such as relative CBV. We defined fractional tumor burden classes with low and high blood volume to distinguish tumor from treatment effect and to determine whether fractional tumor burden can inform treatment-related decision-making.

MATERIALS AND METHODS

Forty-seven patients with high-grade gliomas (primarily glioblastoma) with recurrent contrast-enhancing lesions on DSC-MR imaging were retrospectively evaluated after surgical sampling. Histopathologic examination defined treatment effect versus tumor. Normalized relative CBV thresholds of 1.0 and 1.75 were used to define low, intermediate, and high fractional tumor burden classes in each histopathologically defined group. Performance was assessed with an area under the receiver operating characteristic curve. Consensus agreement among physician raters reporting hypothetic changes in treatment-related decisions based on fractional tumor burden was compared with actual real-time treatment decisions.

RESULTS

Mean lower fractional tumor burden, high fractional tumor burden, and relative CBV of the contrast-enhancing volume were significantly different between treatment effect and tumor (P = .002, P < .001, and P < .001), with tumor having significantly higher fractional tumor burden and relative CBV and lower fractional tumor burden. No significance was found with intermediate fractional tumor burden. Performance of the area under the receiver operating characteristic curve was the following: high fractional tumor burden, 0.85; low fractional tumor burden, 0.7; and relative CBV, 0.81. In comparing treatment decisions, there were disagreements in 7% of tumor and 44% of treatment effect cases; in the latter, all disagreements were in cases with scattered atypical cells.

CONCLUSIONS

High fractional tumor burden and low fractional tumor burden define fractions of the contrast-enhancing lesion volume with high and low blood volume, respectively, and can differentiate treatment effect from tumor in recurrent glioblastomas. Fractional tumor burden maps can also help to inform clinical decision-making.

Read this article: http://bit.ly/2AXsJyu

Perfusion MRI-Based Fractional Tumor Burden Differentiates between Tumor and Treatment Effect in Recurrent Glioblastomas and Informs Clinical Decision-Making
Tags:         
Jeffrey Ross
Fatal error: Uncaught Error: Call to undefined function get_cimyFieldValue() in /home2/ajnrblog/public_html/wp-content/themes/ample-child/author-bio.php:13 Stack trace: #0 /home2/ajnrblog/public_html/wp-content/themes/ample-child/content-single.php(35): include() #1 /home2/ajnrblog/public_html/wp-includes/template.php(812): require('/home2/ajnrblog...') #2 /home2/ajnrblog/public_html/wp-includes/template.php(745): load_template('/home2/ajnrblog...', false, Array) #3 /home2/ajnrblog/public_html/wp-includes/general-template.php(206): locate_template(Array, true, false, Array) #4 /home2/ajnrblog/public_html/wp-content/themes/ample/single.php(21): get_template_part('content', 'single') #5 /home2/ajnrblog/public_html/wp-includes/template-loader.php(106): include('/home2/ajnrblog...') #6 /home2/ajnrblog/public_html/wp-blog-header.php(19): require_once('/home2/ajnrblog...') #7 /home2/ajnrblog/public_html/index.php(17): require('/home2/ajnrblog...') #8 {main} thrown in /home2/ajnrblog/public_html/wp-content/themes/ample-child/author-bio.php on line 13