Lower GI 2017

Conclusive remarks

- IGRT for rectal cancer: relevant to improve accuracy of delivery - Mesorectum changes occurr and can be corrected

only

only in part, is it an issue ? - IGRT for boosting: GTV/rectal motion can be (better) modeled - Even with daily image-guided correction, still relevant residual error due to deformation (margins need to be carefully assessed) - Trend in rectal changes and reduction of motion during long-course RCHT («small» margins were found to be adequate for adaptive SIB in the second part of treatment) - Shrinkage of T may be relevant and may be exploited to optimize adaptive approaches (to boost the residual T) - ART with this approach was implemented (78 pts treated up to now) - Promising results and room for further dose escalation on residual T - Predicting the response based on (mid-RT) MRI response