Multisite Benchmark Study for Standardized Relative CBV in Untreated Brain Metastases Using the DSC-MRI Consensus...

Area of Science:

• Neuroimaging
• Oncology
• Radiology

Background:

• A national consensus protocol for DSC-MRI perfusion data collection was established to standardize relative cerebral blood volume (rCBV) measurements in brain tumors.
• This aims to reduce intersite variability and facilitate comparisons across studies for brain metastases and primary brain tumors.

Purpose of the Study:

• To prospectively collect consensus DSC-MRI data for brain metastases.
• To characterize derived rCBV maps in untreated brain metastases.
• To compare rCBV in brain metastases against glioblastoma (GBM) and normal-appearing brain using the consensus protocol.

Main Methods:

• Multisite prospective study involving 49 patients with untreated brain metastases and 31 with GBM.
• DSC-MRI data collected using a midrange flip angle, GRE-EPI acquisition, and a specific contrast agent protocol.
• Quantitative standardized relative CBV (srCBV) maps generated; comparisons made with normal-appearing white matter (NAWM) and GBM using non-parametric statistical tests.

Main Results:

• Mean srCBV for all brain metastases (1.83±1.05) was significantly lower than for GBM (2.67 ± 1.34) (P = .0009).
• Both metastases and GBM showed significantly higher srCBV than NAWM (0.68 ± 0.18) (P < .0001).
• Distinct metastases, including lung and genitourinary, showed statistically different srCBV compared to GBM.

Conclusions:

• The consensus DSC-MRI protocol successfully determined mean srCBV values for treatment-naïve brain metastases.
• These findings establish a benchmark for srCBV in brain metastases relative to NAWM and GBM.
• This provides a standardized measure for future research adhering to the national consensus recommendation.