Radiation therapy, a widely used method in cancer treatment, employs high-energy radiation to destroy cancer cells or inhibit their growth. However, traditional radiation therapy has some limitations, particularly the potential to damage healthy tissues and the issue of tumor cells developing resistance to radiation. At this point, nanoparticles emerge as a significant innovation and hold great potential in providing targeted treatment in cancer research. According to recent studies, nanoparticles can enhance the effectiveness of therapy by making tumor cells more sensitive to radiation (radiosensitization), allowing the same results to be achieved with lower radiation doses. Additionally, due to their high surface area and reactivity, nanoparticles can serve as drug delivery systems, enabling chemotherapy drugs to reach the tumor site directly and be released in a controlled manner. This reduces systemic side effects and increases treatment efficacy. Nanoparticles used in imaging techniques help detect tumors more precisely, thereby allowing for better management of the treatment process. In the future, the development of smart and multifunctional nanoparticles will facilitate the widespread adoption of personalized treatment approaches and bring about groundbreaking innovations in cancer therapy. These advancements will make radiation therapy more targeted, effective, and safer, significantly improving the quality of life for cancer patients.