S410
Clinical - Gynaecological
ESTRO 2026
Keywords: cervical cancer, FDG-PET
diameter and hemoglobin. Failures were classified a priori as local, local+distant, oligometastatic ( ≤ 5 lesions), or diffuse (>5). Results: CR was observed in 119/161 patients (73.9%). During follow-up, 59/161 (36.6%) failed. Five- year OS was 90.7% (95% CI 83.8–94.7) for CR and 16.4% (95% CI 6.7–29.9) for non-CR. In multivariable analysis, CR remained a strong independent predictor of improved OS (HR 0.079, 95% CI 0.042–0.148; p<0.0001). Among those with recurrence (n=59), the pattern of failure differed by PET response: oligometastatic relapse occurred in 9/17 (52.9%) after CR versus 7/42 (16.7%) after non-CR, yielding a risk difference of +36.3 percentage points (95% CI 10.0–62.5) and an odds ratio of 5.63 (95% CI 1.61–19.66). In the whole cohort, mutually exclusive failure subtypes were distributed as local 4.3%, local+distant 14.9%, diffuse 7.5%, and oligometastatic 9.9%.
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The role of interfractional variations of bladder and rectal filling for vaginal cuff movement by using a rectal balloon in pelvic proton beam therapy Lars B. Wessel 1,2 , Friderike K. Longarino 1,3 , Natalia Sycheva 1,4 , Jan-Hendrik Bolten 1,2 , Hanna Waldsperger 1,2 , Katharina Kozyra 1,2 , Philipp Schröter 1,2 , Fabian Weykamp 1,2 , Eva Meixner 1,2 , Kristin Uzun-Lang 1,2 , Laila König 1,2 , Juergen Debus 1,2 , Nathalie Arians 1,2 1 Department of Radiation Oncology and Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg University Hospital, Heidelberg, Germany. 2 Department of Radiation Oncology, National Center for Tumor diseases (NCT), Heidelberg, Germany. 3 Clinical Cooperation Unit Translational Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany. 4 Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany Purpose/Objective: To assess the interfractional organ movement in patients treated with postoperative proton beam therapy for gynecological cancers and to evaluate the clinical need for the use of rectal balloons (RB) to ensure adequate target coverage. Material/Methods: 23 patients received postoperative active raster-scanning Intensity Modulated Proton Beam Therapy (IMPT) for gynecological cancers between 2017 and 2020 at major
Conclusion: Complete metabolic response on post-RT 18F-FDG PET/CT in LACC is associated with markedly superior survival and a distinct relapse phenotype enriched for oligometastatic disease. These data support response-adapted surveillance: after CR, prioritize whole-body imaging to identify potentially treatable oligometastatic recurrences; for non-CR, especially with central residual/progressive disease, systematically consider salvage surgery when feasible. Prospective, standardized studies are warranted to validate these findings and delineate the clinical and resource implications of response-adapted follow-up.
cancer treatment center in Europe. Positioning verification Computed
Tomography (pv-CT) images were retrieved from hospital databases and registered with the initial planning CT images. On each CT image rectum, bladder and the vaginal cuff (VC) were contoured. The Clinical Target
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