Distinct Cerebrovascular Reactivity Patterns for Brain Radiation Necrosis

Area of Science:

• Neuroimaging
• Oncology
• Radiology

Background:

• Accurate differentiation between radiation necrosis and recurrent glioblastoma is crucial for patient management.
• Current imaging techniques lack precision in distinguishing these conditions.
• Novel imaging biomarkers are needed to improve diagnostic accuracy.

Purpose of the Study:

• To investigate if blood oxygenation-level dependent functional MRI cerebrovascular reactivity (BOLD-CVR) patterns differ between radiation necrosis and recurrent glioblastoma.
• To establish BOLD-CVR as a potential tool for distinguishing these two entities.
• To compare BOLD-CVR in patients with newly diagnosed glioblastoma versus those with radiation necrosis.

Main Methods:

• BOLD-CVR mapping was performed on patients with diagnosed radiation necrosis and newly diagnosed glioblastoma.
• Contrast-enhancing lesions were identified using T1-weighted MRI to define volumes of interest (VOIs).
• Intralesional and perilesional BOLD-CVR values were analyzed using concentric VOIs, and ROC curves assessed discriminative properties.

Main Results:

• Mean intralesional BOLD-CVR was significantly lower in radiation necrosis compared to glioblastoma (p=0.04).
• Distinct perilesional BOLD-CVR patterns were observed, with improvement in radiation necrosis and persistently low values in glioblastoma.
• Combined analysis of intralesional and perilesional BOLD-CVR demonstrated good discrimination between the groups (AUC: 0.85).

Conclusions:

• Distinct intralesional and perilesional BOLD-CVR patterns show potential for differentiating radiation necrosis from recurrent glioblastoma.
• BOLD-CVR may serve as a valuable imaging biomarker in neuro-oncology.
• Further research is warranted to validate these preliminary findings in larger cohorts.