ESTRO 2024 - Abstract Book

S2482

Clinical - Urology

ESTRO 2024

For both V50 Gy and V35 Gy the patients were grouped depending on whether the dose plan did or did not comply with the DVH-constraints. Wilcoxon rank-test was used for testing if there was a difference between the groups.

At data cut-off in September 2023, 223 patients had completed their 12 months FU and could be included in the present study.

Results:

As shown in figure 1 and 2, the groups complying with and violating the V50 Gy constraint respectively differ significantly at the FU 4 weeks after EoT. At the subsequent FU’s the difference is not significant. For V35 Gy the significant difference between these two groups is seen at both 4 weeks and 3 months FU after EoT. The absolute differences for the 4 weeks FU at V50 Gy are 5.8 points. For V35 Gy the differences are 6.8 and 5.3 points at 4 weeks and 3 months, respectively. According to Skolarus et al. [1] the minimally important difference for the bowel domain for EPIC-26 (short form), which has a subset of 6 bowel related items, is in the 4 to 6 point range. Assuming one can extrapolate this result to the 13 bowel related items of the full EPIC questionnaire the differences measured in the present study is most likely clinically relevant.