The aim of this observational study, based on a prospectively collected cohort, is to evaluate the prognostic value of patient-derived organoids in predicting responses to conventional and repurposing drugs, including temozolomide, in patients with primary or recurrent glioblastoma. The primary question is whether the patient's response to temozolomide is recapitulated in their corresponding patient-derived glioblastoma organoid (GBO). Patient drug responses are evaluated using survival data, while GBO drug responses are assessed through a drug-response testing platform utilizing cell viability assays. Additionally, this platform is used to explore the potential application of various chemotherapeutic agents.