This review discusses recent advances and future directions in radiation therapy for cancer treatment. Radiation therapy remains a crucial component of cancer treatment, with approximately 50% of all cancer patients receiving it during their illness. It contributes to about 40% of curative cancer treatment. The main goal of radiation therapy is to prevent cancer cell multiplication by damaging their DNA. Since the discovery of X-rays in 1895 and the Nobel Prize awarded to Marie Curie in 1911 for her research on radium, radiation therapy has evolved significantly. Over the past century, advancements in radiation techniques and understanding of cancer cell biology have improved survival rates and reduced treatment side effects. Radiation therapy uses ionizing radiation to damage cancer cells, with the aim of maximizing damage to cancer cells while minimizing harm to normal cells. There are two main methods of delivering radiation: external beam radiation, which uses high-energy rays from outside the body, and internal radiation (brachytherapy), which uses radioactive sources placed inside the body. Various radiation therapy techniques, such as 3D conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT), and image-guided radiotherapy (IGRT), have been developed to improve treatment accuracy and effectiveness. Particle radiation, including electron, proton, and neutron beams, is also used in cancer treatment. Proton therapy, for example, offers better dose distribution due to its unique absorption profile, allowing maximum energy deposition at the tumor site while minimizing damage to healthy tissues. Particle radiation has higher biological effectiveness than photon radiation, making it more effective for radioresistant cancers. The biological effectiveness of radiation depends on factors such as linear energy transfer (LET), total dose, fractionation rate, and the radio-sensitivity of the targeted cells. Radiation therapy can cause different types of cell death, including apoptosis, mitotic catastrophe, necrosis, and senescence. Understanding these mechanisms is crucial for improving the effectiveness of radiation therapy. Advances in technology and research continue to improve radiation therapy, including the development of more precise delivery systems and a better understanding of the molecular pathways involved in radiation-induced cell death. These advancements aim to enhance the therapeutic ratio and reduce toxicity for cancer patients. Future research will focus on optimizing radiation therapy in combination with other treatment modalities and improving individualized treatment approaches based on genetic profiling.This review discusses recent advances and future directions in radiation therapy for cancer treatment. Radiation therapy remains a crucial component of cancer treatment, with approximately 50% of all cancer patients receiving it during their illness. It contributes to about 40% of curative cancer treatment. The main goal of radiation therapy is to prevent cancer cell multiplication by damaging their DNA. Since the discovery of X-rays in 1895 and the Nobel Prize awarded to Marie Curie in 1911 for her research on radium, radiation therapy has evolved significantly. Over the past century, advancements in radiation techniques and understanding of cancer cell biology have improved survival rates and reduced treatment side effects. Radiation therapy uses ionizing radiation to damage cancer cells, with the aim of maximizing damage to cancer cells while minimizing harm to normal cells. There are two main methods of delivering radiation: external beam radiation, which uses high-energy rays from outside the body, and internal radiation (brachytherapy), which uses radioactive sources placed inside the body. Various radiation therapy techniques, such as 3D conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT), and image-guided radiotherapy (IGRT), have been developed to improve treatment accuracy and effectiveness. Particle radiation, including electron, proton, and neutron beams, is also used in cancer treatment. Proton therapy, for example, offers better dose distribution due to its unique absorption profile, allowing maximum energy deposition at the tumor site while minimizing damage to healthy tissues. Particle radiation has higher biological effectiveness than photon radiation, making it more effective for radioresistant cancers. The biological effectiveness of radiation depends on factors such as linear energy transfer (LET), total dose, fractionation rate, and the radio-sensitivity of the targeted cells. Radiation therapy can cause different types of cell death, including apoptosis, mitotic catastrophe, necrosis, and senescence. Understanding these mechanisms is crucial for improving the effectiveness of radiation therapy. Advances in technology and research continue to improve radiation therapy, including the development of more precise delivery systems and a better understanding of the molecular pathways involved in radiation-induced cell death. These advancements aim to enhance the therapeutic ratio and reduce toxicity for cancer patients. Future research will focus on optimizing radiation therapy in combination with other treatment modalities and improving individualized treatment approaches based on genetic profiling.