Evaluating the role of plan complexity metrics in online adaptive radiotherapy for pancreatic cancer patients Samuele Cavinato, Matteo Galetto, Alessandro Scaggion, Andrea Bettinelli, Matteo Nardini, et al. Medical Physics, 2026 Purpose To systematically investigate the behavior of plan complexity metrics (PCMs) in an MR‐Linac online adaptive radiotherapy (oART) workflow for pancreatic cancer, and to evaluate their potential as surrogate indicators of delivery accuracy. Methods Thirty‐seven patients with locally advanced pancreatic cancer were retrospectively analyzed, yielding 222 MR‐Linac plans (37 reference and 185 delivered fractions). Fifteen PCMs were extracted from plans generated with three optimizers: Penalty, Objectives and Constraints, and A3i (current clinical practice). Plan specific quality assurance (PSQA) has been performed through an independent dose calculation algorithm. Statistical analyses included: (i) inter‐optimizer comparisons (ANOVA and mixed‐effects models), (ii) variance decomposition of adapted‐plan complexity metrics using linear mixed‐effects models (LMEMs), and (iii) evaluation of PSQA stability using statistical process control (SPC) and leave‐one‐patient‐out (LOPO) cross‐validation. Results Optimizer choice strongly influenced plan complexity. The Penalty optimizer generated higher‐complexity plans, whereas Objectives and Constraints and A3i produced more modulation‐efficient configurations with fewer small, low‐MU segments. Variance decomposition identified a subset of metrics that exhibited consistent behavior across all optimizers, serving as robust descriptors independent of the algorithm. Metrics dominated by between‐patient variance (σ 2 between ) emerged as reliable surrogates for patient‐specific complexity Tongue & Groove Index, Average Leaf Gap and Number of Active Leaves consistently showed high between‐patient contributions (σ 2 between > 74%) among others. In contrast, metrics related to low‐MU segments (Seg MU < 5 and Seg MU < 5 [%]) were dominated by within‐patient variance (σ 2 within ), with A3i showing the most pronounced fluctuations (85.8% and 84.8%, respectively). These descriptors are therefore more sensitive to plan‐specific or optimizer‐related stochasticity than to stable patient factors. SPC analyses demonstrated that the current adaptive workflow is robustly stable for most patients: 11 of 13 never experienced a fraction below the tolerance level (TL), and 12 of 13 never exceeded the action level (AL), even when thresholds were dynamically recalculated within the LOPO‐CV. Conclusion This study provides the first systematic assessment of PCMs in MR‐guided oART, demonstrating optimizer‐specific complexity signatures, predominant inter‐patient variability, and the predictive value of selected metrics for delivery accuracy. Although limited to a single tumor site and workflow, the methodology supports the development of institution‐specific, complexity‐aware scorecards to enhance adaptive planning and quality assurance.
“Surviving is not enough”: shifting the focus from treatment success to quality of life in anal cancer survivors. Patient- reported outcomes and the evolving landscape of survivorship care Stefania Manfrida, Natalia Barogi, Viola De Luca, Diana Giannarelli, Loredana Dinapoli, et al. Frontiers in Oncology, 2026 Background Chemoradiotherapy (CRT) is the standard treatment for squamous cell carcinoma of the anal canal (ACC), achieving excellent local control and sphincter preservation. However, many long-term survivors experience persistent bowel, urinary, sexual, and psycho social sequelae affecting quality of life (QoL). The PROACT study (Patient – Reported Outcomes in Anal Cancer Patients Treated with Intensity-Modulated Radiotherapy; NCT06364579) wants to explore the relationship between oncologic outcomes and patient-reported QoL in the era of modern radiotherapy. Methods This single-institution ambispective study included patients with a diagnosis of ACC treated between 2011 and 2024 with intensity modulated radiotherapy (IMRT)-based CRT, followed—when indicated—by an image guided interventional radiotherapy (IRT) boost. Oncologic outcomes and toxicity were assessed using standard criteria. QoL was evaluated annually up to 5 years post-treatment using the EORTC QLQ-C30 and anal cancer–specific QLQ-ANL27 questionnaires. Statistical analyses explored associations between QoL domains and patient-, disease-, and treatment-related factors. Results Median age was 62 years (range 34–83); 82.2% were female. Median follow-up was 51 months. Three- and five-year overall survival were both 97.5%. Disease-free survival was 88.2% and 84.5% at three and five years, respectively, while locoregional relapse-free survival was 92.8% and 89.0%. Colostomy-free survival showed identical rates at three and five years (97.3%). Late≥ G3 Gastrointestinal toxicity occurred in 6 patients (6.7%). Compared with the general population, both sexes reported significantly higher global QoL (males p = 0.002; females p = 0.001), while diarrhea was worst in women ( p = 0.0008). Younger age (<70 years), female sex, and late GI toxicity correlated with poorer functional outcomes, particularly in bowel and sexual domains. Conclusions PROACT underscores that treatment success in anal cancer extends beyond cure, encompassing survivorship, functionality, and well-being. Integrating oncologic and patient-reported outcomes offers a comprehensive, patient-centered framework for optimizing long-term care.
