Approximately 70% of adult patients with primary malignant brain tumors are malignant gliomas, which have high rates of disability and mortality. Even with optimal treatment, patients with glioblastoma (WHO WHO grade 4) have an average survival of 12-15 months, and patients with mesenchymal glioma (WHO grade 3) have an average survival of 2-5 years. The treatment of glioma is a combination of surgery, radiotherapy and chemotherapy. Surgery advocates maximum safe removal of the tumor, and radiotherapy and concurrent chemotherapy are started two weeks after surgery. Tumor cells can complete 1 division cycle in 15 days, so radiotherapy at 2 weeks after surgery may multiply the residual tumor and affect the effect of subsequent radiotherapy and chemotherapy. If radiotherapy is given early, it will affect the wound healing. And chemotherapy drugs do not easily cross the blood-brain barrier and are ineffective. Most gliomas recur within 2-3 cm of the primary site, so local chemotherapeutic drugs draw attention. The Brem research group at Hopkins University in the United States used carmustine (BCNU) extended-release implantation into the surgical residual cavity to treat gliomas, filling the 2-week gap between surgery and the start of radiotherapy, which can improve the efficacy of treating gliomas. It has been approved for marketing by the US FDA and developed countries such as Canada, bringing a boon to the treatment of glioma patients. The only patient with glioblastoma treated by the author who survived for more than 5 years used Gliadel Wafer intraoperatively and is still alive.