Basic Clinical Radiobiology 2017

Summary growth delay assay • Dependent on reliable volume measurement (difficult!) • with ultrasound imaging or bioluminescence more reliable than manual caliper • Only suitable for few logs of tumor cells (selection) • Reflects growth rate of clonogenic and non-clonogenic cells

• Dependent on growth rate of tumor • comparison of different tumors difficult

• drugs may change growth rate (overestimation of efficacy) • radiation damage of vessels changes growth rate (tumor bed effect; overestimation of efficacy)