Does pigmentation, hemosiderin and blood affect visible 5-ALA fluorescence in cerebral melanoma metastasis?

Sodium fluorescein-guided resection of brain metastases: A needed approach or an option? A systematic review and meta-analysis

PURPOSE

Brain metastases (BM) often leave residual tumors despite having visible margins, which increases the risk of local tumor recurrence and can impact overall patient survival rates. Fluorescence-guided surgery (FGS) utilizing sodium fluorescein (FL) has been reported as an effective technique in recent studies. This study aimed to evaluate the efficacy of FL FGS in improving the extent of resection of brain metastases and its impact on overall survival.

METHODS

We conducted a systematic search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Our primary focus was on gross total resection (GTR). Additionally, we extracted survival data and evaluated the risk of bias using a modified version of the Joanna Briggs Institute critical appraisal tool.

RESULTS

The study comprised 970 patients with brain metastases through eight different studies. The study found that patients who underwent FL-guided resection had a significantly higher rate of GTR (OR: 2.02, 95% CI: 1.14-3.56, p = 0.0156, I2 = 41.5%). Additionally, the study concluded that FL-guided resection is associated with better overall survival rates (HR: 0.61, 95%CI: 0.47 0.80, p = 0.0003, I2 = 41.5%).

CONCLUSION

Our research suggests that the use of FL is associated with a higher rate of GTR and improved overall patient survival. None of the studies we reviewed reported significant complications associated with the use of FL in patients.

Intraoperative Fluorophores: An Update on 5-Aminolevulinic Acid and Sodium Fluorescein in Resection of Tumors of the Central Nervous System and Metastatic Lesions-A Systematic Review and Meta-Analysis

INTRODUCTION

Recent advances in tumor visualization have improved the extent of resection (EOR) of primary and secondary tumors of the central nervous system, while limiting the morbidity and mortality of the surgery. One area of recent interest has been the use of intraoperative fluorophores for tumor visualization such as 5-aminolevulinic acid (5-ala) and sodium fluorescein. We performed a systematic review and meta-analysis on the utility of fluorophore administration and EOR with each fluorophore to update the current literature.

METHODS

We conducted a systematic review and meta-analysis on the use of intraoperative 5-ala or fluorescein between 2021 and 2023 using the PubMed, SCOPUS, and WOS databases. The initial search yielded 8688 results. After inclusion and exclusion criteria were met, 44 studies remained for review. A meta-analysis was performed to compare the EOR between studies for each fluorophore and to compare the presence of intraoperative fluorescence by tumor type. Odds ratios (OR) were calculated for gross total resection (GTR), and two-way ANOVA tests were performed to compare rates of intraoperative fluorescence by fluorophore and tumor type.

RESULTS

In all groups except low-grade glioma, fluorescence was present after 5-ala administration; fluorescence was present for all groups after fluorescein administration. Two-way ANOVA analysis for both fluorophores demonstrated no statistically significant difference in presence of fluorescence between type of tumor resected. Meta-analysis of EOR did show a higher, but not significant, rate of GTR in the 5-ala group compared to controls (OR = 1.29, 95% CI = 0.49; 3.37). In the fluorescein group, there were statistically significant higher odds of GTR compared to the control group (OR = 2.10, 95% CI = 1.43; 3.10, I2 = 0%).

CONCLUSIONS

Both 5-ala and sodium fluorescein demonstrated intraoperative fluorescence among various tumor types in both cranial and spinal tumors, as well as efficacy in improving EOR. Both fluorophores merit further investigation for use in surgery of CNS tumors.