Comparison of intracerebrospinal fluid methotrexate by Ommaya reservoir versus lumbar puncture in leptomeningeal carcinomatosis with hydrocephalus: a retrospective cohort study

<title>Abstract</title> Objective The aim of this study was to investigate the clinical efficacy and long-term outcome of different routes of intracerebrospinal fluid (intra-CSF) methotrexate administration in the treatment of leptomeningeal carcinomatosis (LC) with hydrocephalus. Methods A total of 36 patients were included in this retrospective study. 15 patients were enrolled in the Ommaya reservoir (OR) group and 21 in the lumbar punctures (LP) group. Overall survival (OS) was estimated using the Kaplane-Meier method. Prognostic models were constructed using Cox proportional hazards models. Results Of the 36 patients, most primary cancers were non-small cell lung cancer (69.4%) and breast cancer (13.9%). Compared with the LP group, the OR group had higher overall response rate ( <italic>p</italic> = 0.016) and clinical response rate ( <italic>p</italic> = 0.002). Further, the OR group provided better control of intracranial pressure ( <italic>p</italic> = 0.042). All side effects, due to procedure-related complications and drug toxicities, were reported in 4 and 2 patients, respectively. Median OS was 54.7 weeks, in the OR versus 44.1 weeks in the LP group. No statistical difference was observed in the survival of the two groups ( <italic>p</italic> = 0.53). Significant prognostic factors associated with poorer outcome on multivariate analysis were extraneural metastasis ( <italic>p</italic> = 0.01), non-targeted therapy ( <italic>p</italic> &lt; 0.001), and ineffective response after intra-CSF chemotherapy ( <italic>p</italic> = 0.041) . Conclusions Compared with intra-CSF methotrexate administration via LP, OR adminstration did not prolong the OS in LC patients with hydrocephalus. But it was more effective in relieving clinical symptoms and did not increase adverse events. Concomitant targeted therapy and effective response may improve the survival.