TY - JOUR
T1 - Quantification of macrophages in high-grade gliomas by using ferumoxytol-enhanced MRI
T2 - A pilot study
AU - Iv, Michael
AU - Samghabadi, Peyman
AU - Holdsworth, Samantha
AU - Gentles, Andrew
AU - Rezaii, Paymon
AU - Harsh, Griffith
AU - Li, Gordon
AU - Thomas, Reena
AU - Moseley, Michael
AU - Daldrup-Link, Heike E.
AU - Vogel, Hannes
AU - Wintermark, Max
AU - Cheshier, Samuel
AU - Yeom, Kristen W.
PY - 2019/1
Y1 - 2019/1
N2 - Purpose: To investigate ferumoxytol-enhanced MRI as a noninvasive imaging biomarker of macrophages in adults with high-grade gliomas. Materials and Methods: In this prospective study, adults with high-grade gliomas were enrolled between July 2015 and July 2017. Each participant was administered intravenous ferumoxytol (5 mg/kg) and underwent 3.0-T MRI 24 hours later. Two sites in each tumor were selected for intraoperative sampling on the basis of the degree of ferumoxytol-induced signal change. Susceptibility and the relaxation rates R2 ∗ (1/T2 ∗ ) and R2 (1/T2) were obtained by region-of-interest analysis by using the respective postprocessed maps. Each sample was stained with Prussian blue, CD68, CD163, and glial fibrillary acidic protein. Pearson correlation and linear mixed models were performed to assess the relationship between imaging measurements and number of 4003 magnification highpower fields with iron-containing macrophages. Results: Ten adults (four male participants [mean age, 65 years ± 9 {standard deviation}; age range, 57-74 years] and six female participants [mean age, 53 years ± 12 years; age range, 32-65 years]; mean age of all participants, 58 years ± 12 [age range, 32-74 years]) with high-grade gliomas were included. Significant positive correlations were found between susceptibility, R2 ∗ , and R2' and the number of high-power fields with CD163-positive (r range, 0.64-0.71; P , .01) and CD68-positive (r range, 0.55-0.57; P value range, .01-.02) iron-containing macrophages. No significant correlation was found between R2 and CD163- positive (r = 0.33; P = .16) and CD68-positive (r = 0.24; P = .32) iron-containing macrophages. Similar significance results were obtained with linear mixed models. At histopathologic analysis, iron particles were found only in macrophages; none was found in glial fibrillary acidic protein-positive tumor cells. Conclusion: MRI measurements of susceptibility, R2 ∗ , and R2' (R2 ∗ - R2) obtained after ferumoxytol administration correlate with iron-containing macrophage concentration, and this shows their potential as quantitative imaging markers of macrophages in malignant gliomas.
AB - Purpose: To investigate ferumoxytol-enhanced MRI as a noninvasive imaging biomarker of macrophages in adults with high-grade gliomas. Materials and Methods: In this prospective study, adults with high-grade gliomas were enrolled between July 2015 and July 2017. Each participant was administered intravenous ferumoxytol (5 mg/kg) and underwent 3.0-T MRI 24 hours later. Two sites in each tumor were selected for intraoperative sampling on the basis of the degree of ferumoxytol-induced signal change. Susceptibility and the relaxation rates R2 ∗ (1/T2 ∗ ) and R2 (1/T2) were obtained by region-of-interest analysis by using the respective postprocessed maps. Each sample was stained with Prussian blue, CD68, CD163, and glial fibrillary acidic protein. Pearson correlation and linear mixed models were performed to assess the relationship between imaging measurements and number of 4003 magnification highpower fields with iron-containing macrophages. Results: Ten adults (four male participants [mean age, 65 years ± 9 {standard deviation}; age range, 57-74 years] and six female participants [mean age, 53 years ± 12 years; age range, 32-65 years]; mean age of all participants, 58 years ± 12 [age range, 32-74 years]) with high-grade gliomas were included. Significant positive correlations were found between susceptibility, R2 ∗ , and R2' and the number of high-power fields with CD163-positive (r range, 0.64-0.71; P , .01) and CD68-positive (r range, 0.55-0.57; P value range, .01-.02) iron-containing macrophages. No significant correlation was found between R2 and CD163- positive (r = 0.33; P = .16) and CD68-positive (r = 0.24; P = .32) iron-containing macrophages. Similar significance results were obtained with linear mixed models. At histopathologic analysis, iron particles were found only in macrophages; none was found in glial fibrillary acidic protein-positive tumor cells. Conclusion: MRI measurements of susceptibility, R2 ∗ , and R2' (R2 ∗ - R2) obtained after ferumoxytol administration correlate with iron-containing macrophage concentration, and this shows their potential as quantitative imaging markers of macrophages in malignant gliomas.
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U2 - 10.1148/radiol.2018181204
DO - 10.1148/radiol.2018181204
M3 - Article
C2 - 30398435
AN - SCOPUS:85058870707
VL - 290
SP - 198
EP - 206
JO - Radiology
JF - Radiology
SN - 0033-8419
IS - 1
ER -