Association of MRI findings with clinical characteristics and prognosis in patients with leptomeningeal carcinomatosis from non-small cell lung cancer

Purpose Magnetic resonance imagining (MRI) is helpful for diagnosis of leptomeningeal carcinomatosis (LMC) and localizing LMC symptoms. Goal of this study is how MRI findings of LMC are associated with clinical characteristics or prognosis in patients with non-small cell lung cancer (NSCLC). Methods We retrospectively collected data on 283 patients with LMC from NSCLC, adenocarcinoma based on cerebrospinal fluid cytology. All patients had brain MRI with gadolinium enhancement at LMC diagnosis, and spinal MRI was performed at the physician’s discretion. We evaluated the prognostic factors for overall survival (OS) of all patients and subgroup of patients with central nervous system cause of death. Results Two-hundred sixteen patients (76%) had definite or suggestive LMC findings and 67 had negative findings on brain MRI. Of the 37 patients who presented with cauda equina syndrome, 35 (95%) exhibited typical spinal MRI findings. Median OS of all patients was 3.65 months (95% confidence interval, 3.06–4.18). There was no significant difference in median OS between MRI-negative and MRI-positive groups (4.31 vs. 3.48 months, p = 0.711), whereas negative MRI finding showed longer median OS significantly in a subgroup of 77 patients with a central nervous system cause of death ( p = 0.035). Considering clinical characteristics, progressive systemic disease, and altered mentality were significant prognostic factors associated with poor OS, whereas presenting symptom of headache with nausea/vomiting, intra-CSF chemotherapy, WBRT after LMC diagnosis, and concurrent RTKi treatment were significant for favorable OS in multivariable analysis. Conclusions Positive MRI findings suggests heavier disease burden than negative MRI findings in patients with LMC who died of a central nervous system cause. Spinal MRI findings in patients with LMC correlate with cauda equina symptoms.