ESTRO 2025 - Abstract Book

S278

Brachytherapy - Gynaecology

ESTRO 2025

15mm, respectively. For BT-specific structures, the model demonstrated good performance with a median DSC of 0.88 (applicator) and 0.86 (utero-cervix), though lower accuracy for urethra (0.43) and vagina (0.72) (Table 1).

Figure 1. DSC and sDSC2 for female pelvis anatomical structures and gynecological BT applicators

Table 1. Hausdorff 95 (HD95) distance (mm) for the evaluated structures Structure median

mean

std

Bladder

3

6

8

Urethra

9

9

7

Rectum

6

9

8

Colon_Sigmoid

15

23

24

Loops_Bowel

9

20

32

UteroCervix

8

16

26

Vagina

9

11

7

Applicator

8

16

21

Conclusion: The developed brachytherapy model shows strong potential for clinical implementation, achieving high accuracy for most pelvic structures compared to manual segmentation across a multi-institutional dataset. This could significantly improve BT workflow efficiency while maintaining consistency with international guidelines.

Keywords: AI, auto-contouring, brachytherapy