IMRT Course 2016

UCLH strategy

Developed a process for CBCT based dosimetric review. Use CBCT to modify CT – override HU numbers in CT. Head and Neck IMRT – assess impact of weight loss (or gain) though modifications to external contour. Lung - override internal density changes if external shape and positioning is good. Limited ability to quantify impact of positional changes or shifting internal anatomy. Primary aim – assess need for rescan, replan, or revised dose, if: OAR tolerances likely to be exceeded. PTV coverage not achieved. Uncertainty is excessive. 7