Vol. 8, Issue 3, Part F (2022)

Abstract
Outline: The present understanding of the mechanisms of radiation-induced harm in the normal tissue and the available medical treatments to lessen its severity. Higher radiation doses can now be delivered to well-defined tumor target tissues because to advancements in radiation delivery using megavoltage and intensity-modulated radiation treatment. However, the curative treatment of malignancies has a significant danger of damaging vital normal tissues and organs, particularly when radiation and chemotherapy are combined. Depletion of stem tissue and progenitor cells as well as injury to vascular endothelial micro vessels are the main causes of pathogenesis. The recovery and repopulation of stromal stem cells may be chronically hampered by long-lived free radicals, reactive oxygen/nitrogen species, and pro-inflammatory cytokines/chemokines, leading to progressive damage after radiation exposure, according to emerging theories of radiation-induced normal tissue toxicity. It may be possible to gain new insight into the pathogenesis of radiation-induced tissue damage by better understanding the mechanisms governing interactions between excessive reactive oxygen species production, pro-inflammatory cytokine production, activated macrophages, and the role of bone marrow-derived progenitor and stem cells. New targets for preventing or reducing radiation injury to tissues and organs might become apparent with a deeper understanding of the molecular signaling pathways of cytokines and chemokines.