The aim of this study is to dosimetrically validate deformable dose accumulation in online adaptive radiotherapy using realistic physiological tissue deformation and comparing point dose measurements to the treatment planning system-calculated and accumulated point dose. For the data analysis, four real human body donors were used after fixation to preserve physiological tissue elasticity. Online adaptive radiotherapy was performed using the Varian Ethos system for variable bladder and bowel filling as created using catheters. The dose to the bladder, urethra, and rectum was measured using thermoluminescent dosimeters. The measured dose at each point was compared with the sum of the single-fraction adaptive doses and with the accumulated dose. On average, the summation of point doses from the individual fractions (adapted plan as calculated by the Ethos software) is consistent with the accumulated dose, demonstrating internal consistency of the Ethos system regarding deformable dose summation. However, from the 46 point doses analyzed, 22 show deviations larger than ± 10
This study aimed to prospectively compare clinician-reported acute toxicity and patient-reported health-related quality of life (HRQoL) between daily cone-beam CT (CBCT)-based online adaptive radiotherapy (oART) and image-guided radiotherapy (IGRT) in patients with localized prostate cancer treated with moderate hypofractionation. In this prospective study, 74 patients with localized prostate cancer received either CBCT-based oART (n = 43) or CBCT-based IGRT (n = 31) with 62/57.6/48 Gy in 20 fractions, allocated pragmatically by convenience. Acute gastrointestinal (GI) and genitourinary (GU) toxicity was assessed weekly using CTCAE v5.0, and HRQoL was evaluated using the EORTC QLQ-C30 questionnaire at baseline and the end of therapy. Between-group differences were tested using Boschloo’s exact test, Wilcoxon rank-sum test and t-tests; temporal and between-group changes were evaluated based on minimally clinically important differences (MCIDs). Baseline patient and treatment characteristics were similar, except for more high-/very high-risk tumors in the oART group (40.5
Magnetic resonance image-guided adaptive brachytherapy (MR-IGABT) is the standard of care for definitive radiochemotherapy in locally advanced cervical cancer, but radiotherapy departments with sufficient case volume and unrestricted access to MRI capacity remain limited. This study evaluated the feasibility and outcomes of a nationwide Austrian model combining decentralized external-beam radiotherapy (EBRT) with centralized MR-IGABT. This retrospective cohort study included patients with FIGO IB–IVA cervical cancer treated between 2018 and 2022 who received EBRT ± concomitant chemotherapy at external Austrian institutions and were subsequently referred to the Medical University of Vienna for brachytherapy. All patients received four fractions of MR-IGABT with MRI-based target delineation according to GEC-ESTRO recommendations. Primary endpoints were local control (LC) and overall survival (OS). Secondary endpoints included pelvic lymph node control (PLNC), recurrence-free survival (RFS), and grade ≥ 3 morbidity requiring medical intervention. Eighty-nine patients from nine institutions were analyzed. Median age was 52 years; 54
Combined chemoradiotherapy is a key treatment strategy for esophageal cancer in both neoadjuvant and definitive settings. Accurate and consistent target volume delineation is essential to optimize therapeutic efficacy and minimize toxicity. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) enables visualization of metabolically active tumor regions and may improve the accuracy and reproducibility of target volume definition. This retrospective study aimed to evaluate the impact of PET/CT-guided contouring on target volume size, target volume geometry, organ-at-risk exposure, and interobserver variability compared with conventional CT-based delineation. Twenty patients treated between 2022 and 2024 at the Department of Radiation Oncology, University Hospital Magdeburg, were included. Gross tumor volumes (GTVs) were independently delineated on CT and PET/CT datasets. Clinical target volumes (CTVs) and planning target volumes (PTVs) were subsequently generated. Geometric agreement was assessed using the Dice similarity coefficient (DSC) and 95th percentile Hausdorff distance (HD95). Interobserver variability was evaluated using simultaneous truth and performance level estimation (STAPLE)-generated reference contours. Paired t‑tests (α = 0.05) were used to assess volumetric and dosimetric differences. PET/CT-based planning significantly reduced PTV volumes, with mean PTV decreasing from 602.3 ± 267.4 cm3 to 453.2 ± 237.4 cm3 (p < 0.001). In four patients (20
