Existing drug delivery methods have not led to a significant increase in survival for patients with malignant primary brain tumors. While the combination of conventional therapies consisting of surgery, radiotherapy, and chemotherapy has improved survival for some types of brain tumors (e.g., WNT medulloblastoma), other types of brain tumors (e.g., glioblastoma and diffuse midline glioma) still have a poor prognosis. The reason for the differences in response can be largely attributed to the blood–brain barrier (BBB), a specialized structure at the microvasculature level that regulates the transport of molecules across the blood vessels into the brain parenchyma. This structure hampers the delivery of most chemotherapeutic agents for the treatment of primary brain tumors. Several drug delivery methods such as nanoparticles, convection enhanced delivery, focused ultrasound, intranasal delivery, and intra-arterial delivery have been developed to overcome the BBB in primary brain tumors. However, prognosis of most primary brain tumors still remains poor. The heterogeneity of the BBB in primary brain tumors and the distinct vasculature of tumors make it difficult to design a drug delivery method that targets the entire tumor. Drug delivery methods that combine strategies such as focused ultrasound and nanoparticles might be a more successful approach. However, more research is needed to optimize and develop new drug delivery techniques to improve survival of patients with primary brain tumors.

现有的给药方法并未显着提高恶性原发性脑肿瘤患者的生存率。虽然包括手术、放疗和化疗在内的传统疗法的组合提高了某些类型脑肿瘤（例如，WNT 髓母细胞瘤）的生存率，但其他类型的脑肿瘤（例如，胶质母细胞瘤和弥漫性中线胶质瘤）的预后仍然很差。反应差异的原因在很大程度上可以归因于血脑屏障 (BBB)，这是一种微血管水平的特殊结构，可调节分子穿过血管进入脑实质的转运。这种结构阻碍了大多数用于治疗原发性脑肿瘤的化疗药物的递送。几种药物递送方法，例如纳米颗粒，已经开发了对流增强递送、聚焦超声、鼻内递送和动脉内递送来克服原发性脑肿瘤中的 BBB。然而，大多数原发性脑肿瘤的预后仍然很差。原发性脑肿瘤中 BBB 的异质性和肿瘤的独特脉管系统使得设计靶向整个肿瘤的药物递送方法变得困难。结合聚焦超声和纳米粒子等策略的药物输送方法可能是一种更成功的方法。然而，需要更多的研究来优化和开发新的药物递送技术，以提高原发性脑肿瘤患者的生存率。大多数原发性脑肿瘤的预后仍然很差。原发性脑肿瘤中 BBB 的异质性和肿瘤的独特脉管系统使得设计靶向整个肿瘤的药物递送方法变得困难。结合聚焦超声和纳米粒子等策略的药物输送方法可能是一种更成功的方法。然而，需要更多的研究来优化和开发新的药物递送技术，以提高原发性脑肿瘤患者的生存率。大多数原发性脑肿瘤的预后仍然很差。原发性脑肿瘤中 BBB 的异质性和肿瘤的独特脉管系统使得设计靶向整个肿瘤的药物递送方法变得困难。结合聚焦超声和纳米粒子等策略的药物输送方法可能是一种更成功的方法。然而，需要更多的研究来优化和开发新的药物递送技术，以提高原发性脑肿瘤患者的生存率。