NOTQ-02 UTILITY OF SERIAL MRI FINGERPRINTING TO DETECT NEUROCOGNITIVE SUBSTRUCTURES CHANGES IN BRAIN METASTASES PATIENTS
Theodore Arsenault, Andrew Dupuis, Sree Gongala, Robin Ghotra, Prashant Vempati, Kai-Cheng Chuang, Joan Lee, Qing Qing Li, Nan Zhao, Atallah Baydoun, Rasim Boyacioglu, Mark Griswold, Chaitra Badve, Haley PerlowAbstract
MRI fingerprinting (MRF) detects structure-specific relaxometry changes in brain tissue. The purpose of this study is 1) to characterize longitudinal changes in MR Fingerprinting (MRF)-derived T1 and T2 relaxometry within key cognitive structures for brain metastasis patients, and 2) to determine whether MRF changes correlate with the time interval between treatment and post-treatment imaging at the level of individual brain structures. MRF was performed at 1.5 T in 16 patients at pre-treatment baseline, an intermediate scan (128±55 days, n = 3), and post-treatment (157±59 days, range 94–314 days). T1and T2 maps were co-registered to the planning T1Gd using pre-computed rigid-body transforms. CSF-contaminated voxels were excluded (T1 > 2500 ms at 1.5 T). Left and right hippocampal and amygdala structures were combined bilaterally for analysis. Longitudinal MRF changes (PRE→POST) were quantified per structure. At baseline, mean relaxation times were established for the hippocampus (T1=1240±87ms; T2=88±9 ms), amygdala (T1=1204±99 ms; T2=78±8 ms), and corpus callosum (T1=845±88 ms; T2=68±7 ms). While longitudinal changes were observed across all structures—the most prominent being a 2.7% increase in corpus callosum T2 (Δ = 1.79±4.10 ms; d = 0.44)—significant temporal correlations were localized exclusively to the hippocampus (r ≈ -0.65, FDR-corrected p = 0.020), indicating a specific time-dependent decrease in MRF values post-treatment. No significant temporal correlations were observed in the amygdala (p = 0.186) or corpus callosum (p ≥ 0.480). Changes in T1/T2 relaxation times are hypothesis-generating and may represent tissue changes related to cancer burden, radiation therapy, or systemic therapy. These findings support the use of quantitative MRF as a sensitive, regionally resolved biomarker for monitoring brain tissue changes. MRF will be leveraged to develop a cognitive biomarker in the upcoming Athena 3 trial.