Abstract

Background:

Leptomeningeal metastasis from non-small cell lung cancer (LM-NSCLC) is a severe complication of advanced disease, and the prognosis is very poor. This study examined the feasibility of Ommaya reservoir implantation in conducting intraventricular chemotherapy.

Objective:

The aim of the study is to evaluate the efficacy of intrathecal chemotherapy with pemetrexed via Ommaya reservoir in patients with LM-NSCLC in combination with palliative systemic treatment, including immune checkpoint inhibitors and/or bevacizumab. Overall survival (OS), response rate, and adverse events associated with the procedure and drug administration were assessed. LM was evaluated according to the Response Assessment in Neuro-Oncology (RANO) criteria.

Methods:

Twenty-three patients with LM-NSCLC underwent Ommaya reservoir implantation between January 2023 and September 2024. One patient (4.3%) underwent revision surgery due to malfunction and infection. Twenty-three patients received intrathecal chemotherapy with pemetrexed (50mg days 1 and 8, every 3 weeks). The median OS was 10.0 months (95% confidence interval 8.4-11.6 months). RANO-assessed response rate was 78.2% (18/23). The most common adverse event was myelosuppression (n=10; 43.4%).

Conclusion:

Ommaya reservoir implantation combined with sequential repeated intrathecal chemotherapy with pemetrexed is an effective treatment option for patients with NSCLC-LM.