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Indirect effects: stem cells
Solid tumors are organized hierachically and is assumed that they contain
a small population of self-renewing cancer stem cells
Cancer stem cells, especially in their quiescent state are considered
radioresistant
Many cancer stem cells are
located in a perivascular niche
and are
supported by endothelial cells
Hypofractionation preferentially destroys endothelial cells and may
inadvertently eradicate cancer stem cells