10045-MET-4 CEREBROSPINAL FLUID DIVERSION FOLLOWED BY SYSTEMIC THERAPY FOR LEPTOMENINGEAL METASTASIS-RELATED HYDROCEPHALUS IN PATIENTS WITH SOLID CANCER: ASSESSMENT WITH CLASSIFICATION OF EANO-ESMO CLINICAL PRACTICE GUIDELINE

Abstract BACKGROUND Management of leptomeningeal metastasis-related hydrocephalus (LM-H) is particularly challenging to control severe symptoms by intracranial hypertension. The aim of this study is assessment the outcomes of CSF diversion followed by systemic therapy for LM-H in patients with solid cancer. METHODS The authors reviewed 80 patients with LM-H required CSF diversion between October 2008 and May 2023. CSF diversion followed by chemotherapy and/or radiotherapy was indicated when a patient had (1) controlled extra-CNS metastases and (2) systemic life expectancy longer than three months after control of LM. The outcomes were analyzed with Kaplan-Meier estimates. RESULTS The patients consisted of 49 women and 31 men with a mean age of 57 years (range 35-81) . Primary cancers were lung (NSCLC) in 47 (59%), breast (BC) in 16 (20%), gastric (GC) in 10 (13%), cholangiocarcinoma 1 and other cancer in 6. Forty patients (50%) underwent whole brain radiotherapy, 17 patients (21%) cranio-spinal irradiation, and 45 patients (56%) were administrated systemic chemotherapy after CSF diversion. CSF diversion yielded a rapid improvement of their performance status (PS) in 90%. The median OS was significantly longer in patients with maintenance chemotherapy than in those without chemotherapy (4.5 versus 2 months, p<0.001). The patients were classified with EANO-ESMO clinical practice guideline (cytology, MR findings and clinical findings). Type A (linear) in 34, B (Nodular) in 14, C (linear and nodular) in 13 ID (normal) in 19. Linear enhancement groups (IA+IC) were shorter survival than other nodular (IB) and normal findings (ID) (p=0.0038) in long survivor over 6 months. Post-surgical complications were infection in 3, peritoneal dissemination in 2, and shunt malfunction in 1. CONCLUSION Combination of CSF diversion and systemic therapy is a safe and effective strategy in patients with LM-H.