Normal Tissue Radiation Responses

Abstract

Radiation toxicity in normal tissues can be classified as early effects, late effects and consequential late effects. These effects vary based on the tissue type, radiation dose, fractionation, and the volume of tissue irradiated. Parallel organs such as the lung can tolerate high doses to a small volume better than low doses to the whole organ. Serial structures such as the spinal cord can tolerate low doses to the whole organ, but cannot tolerate high doses to a small volume. Two major schemes for tissue classification are the Casarett classifications and Michalowski classifications. Radiation effects on normal tissues are described in a series of paragraphs split up by organ or tissue. Toxicity observed in human patients is scored on a variety of schemas, including Late Effects of Normal Tissue, Subjective Objective Management Analytic (LENT-SOMA) and Common Toxicity Classification for Adverse Events (CTC-AE).