Surgical resection is not recommended, and the principle of treatment is comprehensive, with high-dose methotrexate-based chemotherapy, which can be combined with rituximab, cytarabine and temozolomide depending on the condition, and radiotherapy as treatment for chemotherapy-insensitive or relapsed/refractory PCNSL. The choice of radiotherapy regimen should be decided based on the site and size of the tumor, the patient’s age and physical function for evaluation.