Potential for Differentiation of Pseudoprogression From True Tumor Progression With Dynamic Susceptibility-Weighted Contrast-Enhanced Magnetic Resonance Imaging Using Ferumoxytol vs. Gadoteridol: A Pilot Study

Abstract

Purpose-We evaluated dynamic susceptibility-weighted contrast-enhanced magnetic resonance imaging (DSC-MRI) using gadoteridol in comparison to the iron oxide nanoparticle blood pool agent, ferumoxytol in patients with glioblastoma multiforme (GBM) who received standard radiochemotherapy (RCT).Methods and Materials-Fourteen patients with GBM received standard RCT and underwent 19 MRI sessions that included DSC-MRI acquisitions with gadoteridol on day 1 and ferumoxytol on day 2. Relative cerebral blood volume (rCBV) values were calculated from DSC data obtained from each contrast agent. T1-weighted acquisition post-gadoteridol administration was used to identify enhancing regions.Results-In 7 MRI sessions of clinically presumptive active tumor, gadoteridol-DSC showed low rCBV in 3 and high rCBV in 4, while ferumoxytol-DSC showed high rCBV in all 7 sessions (p=0.002). After RCT, 7 MRI sessions showed increased gadoteridol contrast enhancement on T1-weighted scans coupled with low rCBV without significant differences between contrast agents (p=0.9). Based on post-gadoteridol T1-weighted scans, DSC-MRI, and clinical presentation four patterns of response to RCT were observed: 1) regression, 2) pseudoprogression, 3) true progression, and 4) mixed response.Conclusion-We conclude that DSC-MRI with a blood-pool agent such as ferumoxytol may provide a better monitor of tumor rCBV than DSC-MRI with gadoteridol. Lesions demonstrating increased enhancement on T1-weighted MRI coupled with low ferumoxytol rCBV, are likely exhibiting pseudoprogression, while high rCBV with ferumoxytol is a better marker than

Using iron oxide nanoparticles to diagnose CNS inflammatory diseases and PCNSL

“…Based on our prior work, immediate post-USPIO MRI shows intravascular, not abnormal parenchymal enhancement. [22][23][24] The second day of imaging at 24 hours is a relatively intracellular-weighted (and/or interstitial-weighted) rather than intravascular-weighted MRI given that ferumoxytol has an intravascular halflife of approximately 14 to 20 hours. 25 This proved helpful in one patient in this series who underwent a second diagnostic biopsy in which a different surgical target was selected based on the T2-weighted USPIOenhanced MRI.…”

Dynamic perfusion CT in brain tumors

“…Previous DSC-MR studies showed that true progression had significantly higher relative BV (rBV) than pseudoprogression [34,35] and TIN [36,37]. Using PCT, true progression showed significantly higher values of rBF, rBV, and PS than TIN [38][39][40].…”

The paradoxical effect of bevacizumab in the therapy of malignant gliomas

“…Only select RTOG centers will use DCE and DSC MRI to evaluate tumor perfusion and permeability. 20 Future studies will likely increasingly incorporate dynamic MRI using not only gadolinium-based contrast agents (GBCA), but also blood pool agents such as ferumoxytol, which has demonstrated promising results in the differentiation of progression from pseudoprogression 48 ( figure 5). The timing of bevacizumab administration in the RTOG 0825 study is also concerning.…”

“…The difference was highly statistically significant for ferumoxytol (p Ͻ 0.00001) and significant for gadoteridol (p ϭ 0.01). (From Gahramanov et al 48 Figure reprinted with permission.) These findings suggest that ferumoxytol is a more reliable agent than gadoteridol to determine rCBV in high-grade gliomas.…”