It has long been believed that damage to the GI tract from abdominal radiotherapy was due to its effect on epithelial stem cells. But scientists at Memorial Sloan Kettering Cancer Center have shown that the damage instead results from effects on endothelial cells in the gut microvasculature. The finding not only suggests ways to minimize the GI side effects of radiation, but also implies that angiogenesis inhibitors could be used to lower radiation doses and enhance their effects.

Radiation-induced GI syndrome includes symptoms such as diarrhea and infection that results from destruction of the gut epithelial lining. Since the gut epithelium experiences quick turnover of four to five days, scientists