Perfusion MRI-Based Fractional Tumor Burden Differentiates between Tumor and Treatment Effect in Recurrent...

Area of Science:

• Neuro-oncology
• Radiology
• Medical Imaging

Background:

• Fractional tumor burden (FTB) shows better correlation with histologic tumor volume fraction in treated glioblastoma than other perfusion metrics like relative cerebral blood volume (rCBV).
• Differentiating tumor from treatment effects is crucial for managing recurrent high-grade gliomas.

Purpose of the Study:

• To define fractional tumor burden classes (low and high blood volume) to distinguish tumor from treatment effect.
• To determine if fractional tumor burden can inform treatment-related decision-making in glioblastoma patients.

Main Methods:

• Retrospective evaluation of 47 high-grade glioma patients with recurrent contrast-enhancing lesions.
• Histopathologic examination to define treatment effect versus tumor.
• Analysis of normalized rCBV thresholds to define FTB classes and assessment using area under the receiver operating characteristic curve (AUC).

Main Results:

• Mean lower FTB, high FTB, and rCBV were significantly different between treatment effect and tumor (P < .001).
• AUC for high FTB was 0.85, for low FTB was 0.7, and for rCBV was 0.81.
• Disagreements in treatment decisions occurred in 7% of tumor cases and 44% of treatment effect cases.

Conclusions:

• High and low fractional tumor burden effectively differentiate treatment effect from tumor in recurrent glioblastomas.
• Fractional tumor burden maps can assist in clinical decision-making for glioblastoma management.