Radiation‐Induced Biological Effects: Molecular and Cellular Mechanism, and Applications to Radiation/Nuclear Emergency and Cancer Therapy

Radiation has been wildly used in clinics for disease therapy over a century. However, the side effects associated with radiotherapy are often substantial and multifaceted, underscoring the need for effective management of radiation-induced injuries. Additionally, with the growing reliance on nuclear technology, concerns about accidental exposures have intensified. Radiation-induced biological effects represent a highly complex process that impacts multiple physiological activities within organisms. Ongoing research aims to elucidate the underlying molecular mechanisms and to develop reliable methods for radiation dose estimation-both for emergency scenarios and therapeutic applications. This review provides a systematic overview of the biological effects of ionizing radiation, covering DNA damage and repair pathways, cellular senescence, and diverse modes of cell death. It also offers an in-depth analysis of recent advances in radiation biodosimetry and the application of radiation in cancer therapy, along with insights into future research directions. By integrating mechanistic knowledge with practical applications, this review aims to support the optimization of radiation-based strategies, enhance public health preparedness, and inspire continued innovation in the field.