The Feasibility of Integrating Resting-State fMRI Networks into Radiotherapy Treatment Planning

Area of Science:

• Neuroimaging
• Radiation Oncology
• Cognitive Neuroscience

Background:

• Functional magnetic resonance imaging (fMRI) aids in protecting critical brain regions during radiation therapy for primary brain tumors.
• While task-based fMRI has been explored, resting-state fMRI (rs-fMRI) integration into radiation treatment planning remains underinvestigated.

Purpose of the Study:

• To assess the feasibility of incorporating rs-fMRI data, specifically the default mode network (DMN), into radiation treatment plans for primary brain tumors.
• To compare dosimetry between fMRI-guided and standard treatment plans.
• To estimate the potential reduction in memory loss using normal tissue complication probability models.

Main Methods:

• Retrospective analysis of 9 patients with primary brain tumors.
• Incorporation of DMN data from rs-fMRI into radiation treatment planning.
• Comparison of radiation doses (mean and maximum) to the DMN between fMRI-guided and standard plans.
• Utilized normal tissue complication probability models to predict memory loss risk.

Main Results:

• Achieved significant reductions in mean (20%) and maximum (12%) radiation doses to the DMN (P = 0.002).
• Maintained dose coverage to the planning tumor volume and dose-volume constraints for organs at risk.
• Normal tissue complication probability models indicated a >20% reduction in the probability of memory loss when considering fMRI DMN.

Conclusions:

• Demonstrated the feasibility of using rs-fMRI data to spare cognitively relevant brain regions in radiation treatment planning.
• This approach shows promise for reducing radiation dose to critical brain networks.
• Results support future clinical trials to evaluate the long-term behavioral impact of fMRI-guided radiation therapy.