Some Physical Factors in the Development of Secondary Cancers in Patients Who Have Undergone Radiation Therapy

The paper presents a systematic analysis of physical factors influencing the development of secondary malignant neoplasms in patients who have undergone radiation therapy. Based on clinical data, animal experiments, and epidemiological studies (Hiroshima, Chernobyl), key aspects are considered: the biological effects of ionizing radiation, age- and gender-related differences (increased risks in children and women), localisation of the primary tumor (breast, prostate, head, and neck), as well as radiation therapy methods (photon, proton). Special attention is paid to the role of secondary particles (neutrons, protons) and medical imaging (CT, PET), which increase the cumulative radiation dose. Mathematical models for risk assessment are discussed, taking into account dose, fractionation, and tissue radiosensitivity. The results highlight the need to optimize radiation therapy methods, limit the frequency of diagnostic procedures involving ionizing radiation, and develop personalized approaches to reduce long-term risks.