Lung_Cancer_adaptive - Ethos

A conebeam CT is taken to determine the current tumour extent and the deformations occurring in comparison to the dose distribution to be applied. Normal tissues heart, lung and tracheal tree are automatically contoured by the Ethos therapy system in that cone-beam CT. A specialist physician and a physicist are present during this process. These organ contours are used to determine the extent of the current target volume and the adaptive radiotherapy plan is adjusted to the new target volume. If the current tumour extent is not sufficiently covered by the initial radiotherapy plan planned for the series with its planned tolerances, or if the surrounding normal tissue is exposed to too much radiation, then the online adaptive radiotherapy plan for the current treatment is selected by the specialist. Otherwise, the initial radiotherapy plan is used for IGRT.