Localized delivery of chemotherapeutic drugs to the cancer tissues offers a number of advantages compared to systemic delivery such as its avoidance of systemic chemotherapeutic drug circulation, which leads to less drug waste and decreased side effects and delivery of high dose of the active agent in the tumor which improves the efficacy of the treatment and reduces side effects. We have developed biodegradable medical implants for delivery of localized high dose of therapeutic agents (chemotherapy and radiotherapy) in the tumor bed, and decrease the dose to all other parts of the body, in cancers with localized nature, including glioblastoma, early stage cervical cancer and early stage breast cancer. We have shown significant improvement of the efficacy (up to 100-fold) and reduced side effects (up to 10-fold), which dramatically improved the overall therapeutic strategies for these diseases.