The monograph is devoted to the analysis of catamnetic factors associated with an increased risk of developing late radiation complications. A retrospective analysis of 254 case histories of patients with malignant neoplasms of the cervix and 81 case histories of patients with malignant neoplasms of the breast after radiation therapy on AGAT-R, ROKUS-AM, Clinac 600C and who were hospitalized for late complications of radiation therapy in the department of radiation pathology and palliative medicine of the State Organization "Grigoriev Institute for Medical Radiology and Oncology of the National Academy of Medical Sciences of Ukraine" in the period 1994–2021. The prognostic value of initial hematological and biochemical indicators, as well as clinical and anamnestic parameters in the development of late radiation complications, was established. The monograph will be useful for oncologists, oncogynecologists, radiologists, radiation therapists, radiobiologists, biochemists and students of higher education institutions of medical profile. Tables – 21, figures – 35, bibliography – 81 references.