680 / 1068
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