BCRB 2018

Concept of Functional Sub-Units (FSUs)

lung liver kidney

spinal cord esopha- gus intestine

parallel organisation

serial organisation

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functional damage, if a critical number of FSU’s is inactivated (threshold volume) risk of complication ~ total dose distribution rather than on “hot spots”

Inactivation of one subunit can lead to loss of organ function (binary response) risk of complication strongly influenced by “hot spots”

ESTRO BCR Course / Volume effect in RT – W. Dörr