Efficacy and Safety of Intraventricule Pemetrexed Disodium Administered Via Ommaya Reservoir

confirmed pathologic diagnosis (histologic type of non-squamous non-small cell lung cancer in the primary lesion or metastatic lesion) with definitely genetic testing results (EGFR/ALK/ROS1);

In accordance with the CSCO Guidelines for the Diagnosis and Management of Central Nervous System Tumors, and the EANO-ESMO diagnostic criteria: a diagnosis of type I meningeal metastatic carcinoma is made when cerebrospinal fluid cytology testing reveals anisocytosis (3 consecutive tests are required if the cerebrospinal fluid cytology testing is initially negative for the patient) (one study showed that the specificity of anisocytosis in diagnosing meningeal metastases in patients with solid tumors was 100%) or meningeal lesions Biopsy confirms the diagnosis. (Type IIA-C meningeal metastases: negative or atypical cerebrospinal fluid cytology, MRI showing linear or/and nodular meningeal enhancement^ with typical clinical symptoms*).

MRI: at least 1.5T; demonstrates sulcal, smear, or linear ventricular enhancement, cranial nerve root enhancement or nodular meningeal enhancement, or cauda equina spinal enhancement; control enhancement T1-weighted sequences and Flair sequences; nodularity is defined as foci of ≥ 5x10mm enhancement; sequences of choice: cranial planar enhancement + T2Flair (enhancement) or and total spinal planar enhancement (when suspicion of spinal involvement); 3D T1 enhancement (involved cranial nerves - optional); cerebrospinal fluid flow imaging (functional or anatomic).

Typical clinical manifestations: headache, nausea, vomiting; epilepsy; mental changes, gait difficulties; cranial nerve damage (diplopia, visual abnormalities, hearing abnormalities, facial nerve palsy, difficulty chewing, difficulty swallowing, choking, etc.); neurogenic signs (cauda equina symptoms, mainly perineal numbness, tingling, defecation and urination disturbances, weakness or incomplete paralysis of both lower limbs); sensorimotor defects of the limbs; cervical back Radicular pain; be careful to differentiate from signs and symptoms of brain parenchymal metastases, extracranial disease, treatment-related adverse effects, and non-tumor comorbidities.