Radiobiology: Cells, Effects and Dose-Response

Which Cells Are Sensitive

The law of Bergonie and Tribondeau states that cells are most radiosensitive when they are immature and undifferentiated (stem cells), divide rapidly, have a long dividing future and are metabolically active, while mature, specialized cells that rarely divide are the most resistant. Highly sensitive cells include lymphocytes (the most radiosensitive in the body), spermatogonia, erythroblasts and intestinal crypt cells; endothelial cells, osteoblasts and fibroblasts are intermediate; mature muscle and nerve cells are least sensitive. A cell is most sensitive during mitosis (M phase) and least sensitive in late S phase. This is why embryos, fetuses and children are more sensitive than adults.