ESTRO 2025 - Abstract Book

S852

Clinical - Gynaecology

ESTRO 2025

Results: At diagnosis out of 1425 patients, 760 (53.3%) had LNMs. Median number was 2 (range 0-17) LNMs per patient. Overall, 2359 LNMs were registered: 1644 LNMs (69.7%) in the small pelvis, 426 (18.1%) in the common iliac region, and 253 (10.7%) in PAO-low. Table 1 and 2 provide details for patients and individual LNMs at diagnosis and for treatment aspects. There was a positive correlation between larger nodal CTV and strong FDG positivity (p<0.05). Leading risk factor for elective PAO-irradiation was ≥3 pelvic LNMs in 94 patients and ≥1 LNMs in the common iliac region in 180 patients, respectively, with 73 and 164 being treated according to protocol. PAO-irradiation was also administered in 129 out of 130 patients with PAO-low-LNMs at diagnosis. Of 2359 LNMs, 1969 (83.5%) received nodal boost, and 287 (12.2%) were surgically removed. The initial HR-CTV of the primary tumor was median 59 cc for single vs. >70 cc for multiple LNMs (p<0.05). Regional nodal control including PAO-low+high could be analysed for 1377 patients (data set from 14.11.2024). 120 patients developed nodal failure. Stratified for nodal risk groups at diagnosis, patients without LNMs at diagnosis had superior nodal control compared to patients to 1-2 pelvic, ≥3 pelvic, ≥1 common iliac, and PAO-low-LNMs with 95.6% versus 91.9%, 88.0%, 87.8% and 79.9%, respectively; p<0.001.