Radiobiology 2016

Summary • Response of tumors depends on • intrinsic cellular radiosensitivity • stromal interactions (vasculature) • microenvironment (hypoxia) • tumour volume (stem cell number) • cellular proliferation (repopulation). • Tumor models can be used to explore • different treatment regimes • importance of biological pathways • Volume response: • measure time to regrowth, not regression. • correct for doubling time when comparing tumors • Tumor cure: gold standard • not possible with drugs alone (insufficient kill) • many animals and long time, so only use as confirmation