With these limitations in mind, this study directs attention to two particularly appealing delivery modalities which may improve the efficacy of neuro-oncologic chemotherapeutic agents: liposomes (liposomal irinotecan) and convection enhanced delivery (CED). Liposomes are typically composed of double chain phospholipid amphiphiles (chemical compounds with combined hydrophilic and lipophilic properties) in combination with cholesterol, forming spheroidal bilayer membrane structures that encompass an aqueous internal domain. Based on structural/pharmacologic features, distinct liposome classes have been developed to package various therapeutic agents for the treatment of cancer. From the circulating bloodstream, liposomes are able to diffuse across the blood brain barrier (BBB) due to their lipophilic characteristics. An example is liposomal irinotecan which may reduce the toxicity of irinotecan to healthy tissues while maintaining or increasing its anti-tumor potency.