ESTRO38 Congress Report

RTT

2. Dosimetric benefit of a clinically applied adaptive plan selection strategy for rectal cancer (E38-0922) Rianne de Jong, Jorrit Visser, Niek van Wieringen, Koen Crama, Jan Wiersma, Debby Geijsen, Arjan Bel

Amsterdam UMC, University of Amsterdam, Department of Radiation Oncology, Meibergdreef 9, Amsterdam, the Netherlands

Overview of abstract Plan selection is an adaptive image guidance strategy in radiation therapy where for an individual patient multiple plans are available for treatment. Which plan to use for treatment is based on the anatomy captured on a daily ConebeamCT scan, which is acquired just prior to treatment at the treatment machine. This study compares a clinically implemented adaptive plan selection strategy for rectal cancer to the conventional single plan strategy with respect to target volume coverage and dose to the organs at risk. What were the three main findings of your research? The results of the comparison between the plan selection strategy and the conventional single plan strategy in rectal cancer show that coverage of the target volume is maintained and the dose to the organs at risk (bladder and small bowel) is significantly reduced in favour of the plan selection strategy. On average the reduction is small but can be substantial for individual patients.

What impact could your research have? The results of this study can help a radiation therapy department identify priorities and/or treatment sites when starting with the clinical implementation of plan selection. The study describes the benefits of this strategy for rectal cancer and each department can decide of the benefits outweigh the extra burden. Is this research indicative of a bigger trend in oncology? Plan selection is slowly being implemented as an adaptive strategy based on ConebeamCT scans. After plan selection for bladder and cervix, which is widely described in literature, rectal cancer is now a new site where plan selection can be applied.

RTT | Congress report

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