Efficacy of Slow Rate Ventriculolumbar Perfusion Chemotherapy for Leptomeningeal Carcinomatosis: Interim Result of a Phase II Study

Background To evaluate the efficacy of modified ventriculolumbar perfusion (VLP) chemotherapy with methotrexate on leptomeningeal carcinomatosis in terms of symptomatic response and side effects. Methods Previous infusion rate of 20 mL/h was reduced to 15 mL/h for the purpose of decreasing constitutional side effects of VLP such as nausea/vomiting, insomnia and confusion. The primary outcome was the response rate of increased intracranial pressure (ICP), and the secondary outcome was the occurrence of side effects compared to previous 20 mL/h trial. This interim analysis to validate the reduced infusion rate is not to affect the original effect of VLP chemotherapy. Results All forty-seven patients were enrolled including 22 patients with increased ICP. Thirteen patients out of these (59%) got normalized ICP after VLP chemotherapy. Moderate to severe (grade 2-3) confusion was observed in 3 patients (6%) and it was significantly reduced compared to those (23%) in the VLP 20 mL/h (p=0.017). Grade 2-3 nausea/vomiting was also reduced from 64% to 45% but failed to reach statistical significance (p=0.08). Median overall survival (OS) was 5.3 months (95% confidence interval, 3.55-7.05) and patients OS, who received maintenance VLP was significantly prolonged compared to patients who underwent induction VLP only (5.8 vs. 3.4 months, p=0.025). Conclusion VLP of reduced perfusion rate (15 mL/h) showed compatible control rate of increased ICP at this interim analysis. Decreased moderate to severe side effects and prolonged OS in patients received maintenance VLP encourage us to evaluate the effectiveness of this trial further.