Early DCE and DSC MRI Parameters Predict Midterm Outcomes in Lung Cancer Brain Metastases

Overview

This study evaluates early post-stereotactic radiosurgery (SRS) dynamic contrast-enhanced (DCE) and dynamic susceptibility contrast (DSC) MRI parameters as predictors of midterm outcomes in lung cancer brain metastases. Early alterations in perfusion metrics such as K-trans, Ve, Vp, and normalized cerebral blood volume (nCBV) were correlated with tumor response at 6 to 12 months post-SRS.

Background

Brain metastases from lung carcinoma represent the most common source of metastatic brain tumors, comprising 50% of cases. Despite advances in systemic therapies, prognosis remains poor. Stereotactic radiosurgery is preferred for non-surgical brain metastases due to its ability to spare healthy brain tissue and achieve local control. However, predicting midterm tumor response after SRS is challenging, necessitating imaging biomarkers beyond conventional MRI. Perfusion MRI techniques like DCE and DSC provide insights into tumor vascularity and angiogenesis, potentially serving as early predictors of treatment outcomes.

Data Highlights

The study included lung cancer patients with brain metastases undergoing SRS, with MRI perfusion imaging performed before and 4–8 weeks after treatment, and follow-up at ≥6 months. Lesion volumes were measured at baseline, early post-SRS, and midterm phases. Perfusion parameters assessed included K-trans, Ve, Vp from DCE-MRI, and normalized cerebral blood volume (nCBV) from DSC-MRI. Midterm outcomes were classified as responders (complete response, partial response, or stable disease) or non-responders (radiological progression and clinical deterioration) based on RANO-BM criteria.

Key Findings

• Early post-SRS DCE-MRI parameters such as K-trans, Ve, and Vp showed significant differences between responders and non-responders at midterm follow-up.
• DSC-MRI derived normalized cerebral blood volume (nCBV) was higher in non-responders, indicating increased tumor angiogenesis associated with progression.
• Dynamic changes in perfusion parameters from baseline to early post-SRS correlated with midterm tumor control status.
• Lesion volume measurements confirmed that responders exhibited stable or reduced tumor size, whereas non-responders showed >20% volume increase with associated edema.
• Clinical deterioration aligned with radiological progression in non-responders, validating the imaging biomarkers' prognostic value.

Clinical Implications

Early post-treatment perfusion MRI parameters can serve as valuable biomarkers to predict midterm outcomes in lung cancer brain metastases treated with SRS. Incorporating DCE and DSC perfusion imaging into routine post-SRS surveillance may help identify patients at risk of progression, enabling timely therapeutic adjustments. This approach supports personalized management and may improve local control and patient quality of life.

Conclusion

Early alterations in DCE and DSC perfusion MRI parameters after SRS provide prognostic information regarding midterm tumor control in lung cancer brain metastases. These imaging biomarkers hold promise for guiding clinical decision-making and optimizing patient outcomes.

References

1. References 1-13 from source article