Perilesional Edema Volume Predicts Response to Stereotactic Radiosurgery in Melanoma Brain Metastases

Overview

This retrospective study evaluated the impact of perilesional edema volume (PEV) on intracranial response and survival in melanoma brain metastases (MBM) treated with stereotactic radiotherapy (SRT) and systemic therapy. Findings indicate that a PEV cutoff of 0.5 cc significantly predicts local intracranial progression-free survival and treatment response.

Background

Melanoma brain metastases pose a significant treatment challenge due to their aggressive nature and poor prognosis. Stereotactic radiotherapy (SRT) is a key local treatment modality offering high local control rates and better quality of life compared to whole brain radiation therapy. Despite advances in systemic therapies, predictive factors for response to SRT in MBM remain limited. Perilesional edema volume (PEV) has been linked to treatment resistance in other cancers but its role in melanoma brain metastases is unclear.

Data Highlights

Key Findings

• Perilesional edema volume (PEV) above 0.5 cc is associated with significantly worse local intracranial progression-free survival (p = 0.001).
• PEV quantification was performed using 3D segmentation of FLAIR/T2-weighted MRI images with 3D Slicer software.
• Patients with lower PEV demonstrated higher intracranial objective response rates (complete or partial response) following SRT.
• SRT combined with systemic therapies was individualized based on multidisciplinary tumor board decisions.
• Exclusion criteria ensured a homogeneous cohort by omitting prior treatments and meningeal carcinomatosis cases.

Clinical Implications

Quantifying perilesional edema volume via MRI prior to stereotactic radiotherapy can serve as a valuable predictive biomarker for treatment response in melanoma brain metastases. Incorporating PEV assessment into clinical workflows may help identify patients more likely to benefit from SRT and guide personalized treatment planning. This approach supports optimizing local control and potentially improving survival outcomes.

Conclusion

Perilesional edema volume is a significant predictor of intracranial response and progression-free survival in melanoma brain metastases treated with stereotactic radiotherapy. Integrating PEV measurement into clinical evaluation may enhance prognostication and treatment decision-making.

References

1. Multiple sources (2020-2023) -- Evaluating the Role of Perilesional Edema Volume in Predicting Response to Stereotactic Radiosurgery in Melanoma Brain Metastases