S60
Brachytherapy - Gynaecology
ESTRO 2026
minimal toxicity. Tumour stage, size, and total HR-CTV D90 (EQD2) were principal determinants of outcome. The finding that higher D90 did not improve survival underscores the need for volume-adjusted dose– response modelling and individualized adaptive planning when optimizing hybrid brachytherapy for LACC.The study protocol was approved by the Ethics Committee of Tianjin Medical University Cancer Institute & Hospital (Approval Number: bc20254228). All patients provided written informed consent prior to participation in the study. Keywords: EQD2 dose–response, 3D-printed template, Outcome References: 1. Haie-Meder C et al. GEC-ESTRO (I): Concepts for 3D image-based cervical cancer brachytherapy. Radiother Oncol. 2005;74:235-245.2. Pötter R et al. GEC-ESTRO (II): 3D dose-volume parameters in cervix brachytherapy. Radiother Oncol. 2006;78:67-77.3. ICRU Report 89: Prescribing, Recording and Reporting Brachytherapy for Cancer of the Cervix. Oxford Univ Press; 2016.4. Pötter R et al. EMBRACE II: MRI-guided adaptive brachytherapy in locally advanced cervical cancer. Radiother Oncol. 2021;160:185-193.5. Lindegaard JC et al. RetroEMBRACE: MRI-guided interstitial brachytherapy improves outcome in advanced cervical cancer. Radiother Oncol. 2016;120:428-433. Digital Poster 2134 Treatment approach and outcome in patients with locoregional recurrent endometrial cancer. Heidi MA Rütten 1 , Hanne MA Heerkens 1 , Ruud MA van Leeuwen 1 , Marleen MA Kok 1 , Inge MA Struis 1 , Johanna MA Pijnenborg 2 , Lia MA Verhoef 1 1 Radiation Oncology, Radboud university medical centre, Nijmegen, Netherlands. 2 Obstetrics & Gynaecology,, Radboud university medical centre, Nijmegen, Netherlands Purpose/Objective: Treatment of locoregional recurrent endometrial cancer is challenging especially when patients are previously irradiated. Most often a combination of external beam radiotherapy (EBRT) and brachytherapy (BT) is used. Aim of this study was to analyse treatment and outcome in patients with a locoregional recurrence. Material/Methods: Patients with locoregional recurrent endometrial cancer diagnosed between 2014 and 2024 and treated with radiotherapy with curative intent at our institution were selected. Data on tumour characteristics, treatment, radiotherapy dose and technique and outcome were collected.
aims (HR-CTV D90 ≥ 85–90 Gy EQD2; OARs within tolerance). Survival was estimated by Kaplan–Meier and Cox models. Results: Median HR-CTV volume was 55.9 cm ³ and median D90 92.9 Gy (EQD2). All OAR D2cc medians met ICRU-89 constraints.Procedural feasibility was high, with a median of 7 needles per fraction, mean implant time 4.2 minutes, and only 1.7% major bleeding events. The hybrid workflow was reproducible and safe in >500 insertions.At a median follow-up of 20.1 months, the 3-year OS, PFS and LRFS were 89.8%, 83.2%, and 95.0%.Univariate Cox analysis identified HR-CTV D90 (per 5 Gy, HR 2.44, p = 0.026), tumour size > 6 cm (HR 3.47, p = 0.042), and advanced FIGO stage (p = 0.021) as significant predictors of OS/PFS; all retained borderline significance in multivariate models (p ≈ 0.07–0.09).Survival analysis showed that patients receiving HR-CTV D90 ≥ 93 Gy had poorer OS and PFS, reflecting that higher dose groups represented larger or more advanced tumours requiring escalation rather than a direct benefit from higher dose. Dose–response evaluation indicated a plateau around 93 Gy EQD2.Severe late GI/GU toxicities ( ≥ G3) occurred in 2.5% and 1.7%, with no grade 4–5 events.
Figure1. Forest plots of univariate and multivariate Cox regression for OS and PFS showing HRs (95% CIs).
Figure2. Kaplan–Meier survival curves stratified by HR- CTV D90 ( ≥ 93 Gy vs < 93 Gy). Conclusion: Patient-specific multimodality 3D-guided hybrid IGBT was feasible and achieved excellent local control with
Made with FlippingBook - Share PDF online