To characterize the rapid pharmacodynamic profile of intravenous L-arginine on lactate metabolism in brain metastases, highlighting its potential to enhance radiotherapy efficacy.
Key Findings:
The pooled L-arginine group showed significantly greater lactate reduction at T3 compared to controls (median ΔLac_T3: −1.09 vs. 0.00, p = 0.0012).
The 30 g dose group exhibited the most pronounced lactate reduction, with a peak of 63.5% at 30 minutes (ρ = −0.753, p < 0.001).
No treatment-related adverse events were reported up to 24 hours post-infusion.
Interpretation:
Intravenous L-arginine rapidly and safely suppresses lactate metabolism in brain metastases, suggesting a promising avenue for enhancing radiotherapy efficacy, particularly at the 30 g dose.
Limitations:
Small sample size limits the ability to make definitive conclusions, necessitating cautious interpretation of results.
No formal sample size calculation was performed for this exploratory study, which may affect the robustness of the findings.
Conclusion:
The study suggests that a regimen of '30 g L-arginine followed by radiotherapy within 30 minutes' is a candidate for validation in future phase II trials, potentially improving treatment outcomes for patients with brain metastases.
