Physics and Imaging in Radiation Oncology最新文献

{"title":"Raman spectroscopy and atomic force microscopy as tools to evaluate the radiobiological sensitivity of breast cancer cells at different therapeutic doses","authors":"Martha A. Iñiguez Beltrán ,&nbsp;Mónica A. Acosta Elías ,&nbsp;Erika Silva Campa ,&nbsp;Aracely Angulo Molina ,&nbsp;Alexel J. Burgara Estrella ,&nbsp;Perla E. Medina Corral ,&nbsp;Javier A. Murillo Quijada ,&nbsp;José A. Sarabia Sainz ,&nbsp;Rodrigo Melendrez Amavizca ,&nbsp;Antonio Cota Rodríguez","doi":"10.1016/j.phro.2026.100982","DOIUrl":"10.1016/j.phro.2026.100982","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Radiotherapy is widely used as a treatment for patients with breast cancer (BC). In vitro irradiation of BC cells provides a strategy to investigate early cellular and molecular events induced by ionizing radiation. Characterizing structural and membrane responses may identify biomarkers of radiosensitivity, improving understanding of treatment effects and enabling patient specific optimization. In this work, Raman spectroscopy and atomic force microscopy (AFM) were applied in vitro to investigate mechanisms relevant to BC radiotherapy.</div></div><div><h3>Materials and methods</h3><div>Breast cancer cell line MD Anderson-Metastatic Breast-231 (MDA-MB-231) was exposed to doses of 2, 4, and 10 Gy. Non-irradiated BC cells were used as control samples. Samples were incubated at 37 °C, 5% carbon dioxide (CO₂), and analyzed at 0, 24, and 48 h post-irradiation using AFM and Raman spectroscopy to detect morphological and biochemical changes.</div></div><div><h3>Results</h3><div>Raman spectroscopy showed significantly increased intensities at 1250, 1455, and 1670 cm⁻¹ at 24 h, followed by decreases at 48 h (4–10 Gy). Atomic force microscopy showed reduced membrane roughness at 0 h from 34.0 ± 3.4 nm in controls to 23.6 ± 2.9 nm at 10 Gy, and from 39.50 ± 6.05 nm to 26.86 ± 5.44 nm at 48 h. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay showed reduced viability at 48 h: 84.0% (2 Gy), 81.5% (4 Gy), and 80.3% (10 Gy).</div></div><div><h3>Conclusions</h3><div>Raman spectroscopy and AFM demonstrate the capability to detect early radiation-induced chemical and surface alterations, suggesting potential utility for identifying biomarkers of radiotherapeutic response in breast cancer cells.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"39 ","pages":"Article 100982"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147805789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of a quasi-automatic treatment planning workflow for head-and-neck cancer in radiotherapy","authors":"Moritz Westermayer ,&nbsp;Daniela Sandu ,&nbsp;Cécile Laude ,&nbsp;Séverine Racadot ,&nbsp;Anne-Agathe Serre ,&nbsp;David Sarrut ,&nbsp;Marie-Claude Biston","doi":"10.1016/j.phro.2026.100983","DOIUrl":"10.1016/j.phro.2026.100983","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Automation of radiotherapy workflows enhances efficiency, consistency and would support adaptive online dosimetry on standard linacs. This study investigated the feasibility and quality of a quasi-automatic treatment planning workflow for head-and-neck cancer.</div></div><div><h3>Materials and methods</h3><div>Forty head-and-neck cancer patients previously treated with VMAT were included. Clinical plans were optimized using manually delineated targets and corrected organs-at-risk (OARs) autocontours. Autoplans were generated using clinical and uncorrected autocontours of OARs and CTVn levels, with macroscopic tumors copied from clinical contours. Dose differences between auto- and clinical plans were quantified by projecting autoplans onto clinical contours post-optimization. For 10 patients, 5 medical experts (MEs) manually delineated CTVn levels. Inter‑observer variability (IOV) and mean autocontour deviation from experts (MAV) were quantified using Dice Similarity Coefficient (DSC), surface‑DSC, and 95th percentile-Hausdorff distance (HD_95%). IOV‑derived asymmetric safety margins around PTVn autocontours were computed from Euclidean distances.</div></div><div><h3>Results</h3><div>Autoplans optimized on clinical contours achieved comparable or superior sparing of OARs with higher PTV coverage. Autoplans based on uncorrected autocontours also improved OARs sparing but showed significantly lower target coverage compared to clinical plans (meanV_95%: 91.9 ± 4.2% vs 98.0 ± 0.9%, p &lt; 0.001). HD_95% and surface Dice scores demonstrated significant differences in CTVn contours for two MEs relative to other MEs (p &lt; 0.05). Applying quantified IOV-based safety margins resulted in meanV_95% of 95.1 ± 5.4%, while no significant impact on OARs dose was observed (p &gt; 0.4).</div></div><div><h3>Conclusions</h3><div>The quasi‑automatic workflow generated clinically acceptable, often superior plans. IOV‑based CTVn margins enhanced robustness and may hasten clinical adoption.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"39 ","pages":"Article 100983"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147805792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of gantry-less magnetic resonance guided proton therapy with photon therapy for hepatocellular carcinoma patients","authors":"Franciska Lebbink ,&nbsp;Emilie Alvarez Michael ,&nbsp;Anna Kornek ,&nbsp;Annika Lattermann ,&nbsp;Chiara Valentini ,&nbsp;Petra Trnkova ,&nbsp;Esther G.C. Troost","doi":"10.1016/j.phro.2026.100967","DOIUrl":"10.1016/j.phro.2026.100967","url":null,"abstract":"<div><div>Background and purpose: With magnetic resonance imaging (MRI), soft-tissue tumors such as hepatocellular carcinoma (HCC) are visualised. MR guided proton therapy (MRgPT) may combine the advantages of proton therapy with soft-tissue image-guidance. Therefore, we assessed the calculated dose differences between MR-guided photon therapy (MR-LINAC) and MRgPT at a horizontal beamline for HCC patients, considering non-adapted and adapted plans.</div><div>Materials and Methods: Planning computed tomography and T2-weighted MRI of ten HCC patients with 13 lesions were included. Adaptive hypofractionated MR-LINAC, gantry-based PT as well as MRgPT treatment plans at a horizontal beamline were optimized using RayStation 2023B-R on the daily MRIs. The comparison included various dose-volume-histogram (DVH) parameters of target volumes and normal tissue.</div><div>Results: Clinical target volume (CTV) coverage could be fulfilled for 12/13 cases, where plan adaptation was required for 41, 36 and 15 out of 65 fractions for MRgPT, gantry-based PT and MR-LINAC, respectively. With plan adaptation, the <em>D</em>_98%<em>_,CTV</em> could be restored for 56, 60 and 59 fractions, respectively. The median adapted <em>D_avg</em> of the uninvolved liver was reduced from 10.1 Gy for MR-LINAC to 6.1 Gy(RBE) for MRgPT, and 4.5 Gy(RBE) for gantry-based PT. For all adapted plans, the normal tissue constraints were fulfilled in all patients.</div><div>Conclusions: More than half of the proton fractions needed plan adaptation for adequate target coverage. MRgPT lead to clinically acceptable treatment plans for HCC patients and reduced the dose to the uninvolved liver compared to MR-LINAC, with similar target coverage. HCC may thus be a promising indication for hypofractionated adaptive MRgPT.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"39 ","pages":"Article 100967"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147805795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel audit methodology to improve detection of planning and delivery errors in passive motion management","authors":"Alex Burton ,&nbsp;Sabeena Beveridge ,&nbsp;Nicholas Hardcastle ,&nbsp;Rick Franich","doi":"10.1016/j.phro.2026.100976","DOIUrl":"10.1016/j.phro.2026.100976","url":null,"abstract":"<div><h3>Background and purpose</h3><div>End-to-end dosimetry audits, including respiratory motion, typically compare film measurements acquired in a moving frame directly to planned dose distributions that do not resolve the applied motion. Inherent motion-induced dose differences cannot be distinguished from error-induced differences in this analysis. An alternate comparison approach is proposed utilising both motion-coupled and decoupled film measurements to overcome the motion-induced differences, and improve error detection.</div></div><div><h3>Materials and methods</h3><div>Reference internal target volume-based plans were created for lung and liver SBRT treatment sites in the ACDS motion phantom. A series of planning and delivery errors were introduced, and 4D dose accumulation was used to estimate the delivered dose. All plans were delivered to the phantom loaded with two films, analysed using gamma criteria ranging from 3%/1mm to 7%/5mm. A receiver operator characteristic decision matrix based on the gamma passing rate and 4D dose difference to reference (<span><math><mrow><mfenced><mrow><mi>Δ</mi><mn>4</mn><mi>D</mi></mrow></mfenced></mrow></math></span>) was used to calculate sensitivity/specificity using the standard and proposed (test) comparison approaches.</div></div><div><h3>Results</h3><div>7/13 introduced errors had <span><math><mrow><mfenced><mrow><mi>Δ</mi><mn>4</mn><mi>D</mi></mrow></mfenced></mrow></math></span> ≥ 5% (range: −21.0% to + 3.0%). 3/25 combinations in the standard arm had sensitivity and specificity ≥ 0.5, versus 9/25 in the test arm. Standard analysis performed optimally using 5%/3mm criteria (sensitivity = 1.0, specificity = 0.62). The test arm had equal sensitivity with improved specificity (0.75) using 4%/2mm criteria.</div></div><div><h3>Conclusions</h3><div>Film measurements acquired in a moving frame are over-sensitive with low specificity. Eliminating the impact of motion using the proposed measurement/analysis approach enables more stringent gamma criteria (4%/2mm versus 5%/3mm) for better classification accuracy.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"39 ","pages":"Article 100976"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147805790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"External beam focal boost radiotherapy to intraprostatic lesions in prostate cancer: a scoping review","authors":"Ying Liu ,&nbsp;Shangbin Qin ,&nbsp;Xueying Ren ,&nbsp;Yun Bai ,&nbsp;Xianshu Gao ,&nbsp;Hongzhen Li ,&nbsp;Mingwei Ma","doi":"10.1016/j.phro.2026.100980","DOIUrl":"10.1016/j.phro.2026.100980","url":null,"abstract":"<div><h3>Background</h3><div>Focal boost external beam radiation therapy (EBRT) delivers an escalated dose to intraprostatic lesions (IPLs) in prostate cancer. It is an emerging field characterized by highly heterogeneous practices.</div></div><div><h3>Materials and methods</h3><div>This scoping review was conducted with adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines. Eligible reports were reports detailing treatment methods and outcomes of focal boost EBRT in prostate cancer.</div></div><div><h3>Results</h3><div>Forty-two studies were reviewed. Fractionation shifted over time from conventional to moderate and ultra hypofractionation. Patient populations were largely high-risk localized disease. Assuming α/β = 1.5, equivalent IPL boost dose in 2 Gy/fraction spanned 71.3–138 Gy in 32–45 fractions with conventional fractionation, 81.5–112.5 Gy in 15–25 fractions with moderate hypofractionation, and 96.4–196.4 Gy in 2–5 fractions with ultra hypofractionation. Multiparametric magnetic resonance imaging (MRI) was used for IPL delineation in 39 studies, and positron emission tomography/computed tomography (PET/CT) in five studies. Five-year biochemical disease-free survival and overall survival were: conventional fractionation 92–98.2% &amp; 100%, moderate 75.2–96.7% &amp; not reported, and ultra hypofractionation 93.2–100% &amp; 86–100%. Median ≥ Grade 2 genitourinary/gastrointestinal toxicities were &lt; 45% and ≥ Grade 3 &lt; 10%.</div></div><div><h3>Conclusions</h3><div>Focal boost EBRT appears feasible and may improve biochemical control without increasing toxicity, particularly in high-risk disease. However, optimal dose/fractionation, organ at risk constraints, and long-term survival benefits remain undefined. Large, preferably multicenter prospective studies involving several hundred patients, with standardized endpoints and comprehensive toxicity assessment are warranted.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"39 ","pages":"Article 100980"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147805794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Auto-segmentation and dose accuracy evaluation of synthetic computed tomography generated from pelvis cone-beam computed tomography images using a cycle-generative adversarial network with a novel loss function","authors":"Silambarasan Anbumani ,&nbsp;Andrew Keeler ,&nbsp;Jiaofeng Xu ,&nbsp;Daniel Thill ,&nbsp;Nicolette O’Connell ,&nbsp;Eric Paulson ,&nbsp;Monica E. Shukla ,&nbsp;Eenas A. Omari","doi":"10.1016/j.phro.2026.100972","DOIUrl":"10.1016/j.phro.2026.100972","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Synthetic CT (sCT) images generated from cone-beam CT (CBCT) images have shown improved image quality over CBCT images. This work evaluated a deep learning (DL)-based sCT model with the potential to facilitate accurate adaptive radiotherapy for pelvis patients.</div></div><div><h3>Materials and methods</h3><div>A DL-based cycle-Generative Adversarial Network (cycleGAN) model, incorporating a novel loss function to enhance structural image similarity, was used to generate sCT images from CBCT images acquired on a conventional c-arm Linac during intensity-modulated radiotherapy. Auto-segmentation accuracy for 10 pelvic structures was assessed compared to physician-drawn contours using Dice similarity coefficients (DSC), Hausdorff distance (HD), and mean distance-to-agreement (MDA). CT numbers for pelvic organs-of-interest were compared between sCT and planning CT (refCT). Dose, calculated using a Monte Carlo algorithm, was compared using relative dose differences to the gross tumor volume (GTV) for D_98%, D_50%, and D_2% between sCT and recalculated refCT, alongside 3D-global gamma analysis with 3%/3mm, 2%/2mm, and 1%/2mm criteria.</div></div><div><h3>Results</h3><div>The sCTs demonstrated high auto-segmentation accuracy with DSC &gt; 0.8 and MDA &lt; 2 mm, except for the small bowel and colon. CT number differences were within published tolerances to achieve less than 1% dose difference excepting structures with substantial gas variations compared to the refCT. The mean dose difference to the GTV was 0.3%±0.6 across D_98%, D_50%, and D_2%. 3D-gamma passing rates were 97 ± 2% for the most restrictive criterion used, 1%/2mm.</div></div><div><h3>Conclusions</h3><div>The improved cycleGAN-based CBCT-to-sCT model generated high-quality sCT images that may be directly utilized for image segmentation and dose calculation to advance adaptive radiotherapy on conventional Linacs.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"39 ","pages":"Article 100972"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147851536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Necessity of energy layer repainting for proton radiotherapy in breast cancer patients","authors":"Bojan Štrbac,&nbsp;Truls Andersen,&nbsp;Jeffrey Free,&nbsp;Pietro Piscotta,&nbsp;John Maduro,&nbsp;Johannes A. Langendijk","doi":"10.1016/j.phro.2026.100971","DOIUrl":"10.1016/j.phro.2026.100971","url":null,"abstract":"<div><div>This study assessed the necessity of energy layer repainting for free-breathing breast proton therapy using pencil beam scanning (PBS). Ten patients were analyzed via log file-based 4D dose reconstruction across three scenarios: no repainting (1×), 3×, and 5× energy-layer repainting. Median target coverage deviations (D₉₈%) remained within ±4.1% for all strategies, with no statistically significant differences (p &gt; 0.05). Respiratory motion was minimal (mean &lt;2.2 mm)<strong>,</strong> while delivery time increased substantially with repainting. For free-breathing breast PBS with minimal respiratory motion, small target excursions, intra-fraction delivery averaging, and conventional fractionation rendered energy layer repainting unnecessary.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"39 ","pages":"Article 100971"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147805655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparative assessment of deep learning and knowledge-based dose prediction models for advanced radiotherapy planning of prostate cancer with focal boosting","authors":"Maria A. Piliero ,&nbsp;Antonio Angrisani ,&nbsp;Davide G. Bosetti ,&nbsp;Margherita Casiraghi ,&nbsp;Francesco Castronovo ,&nbsp;Nicolas Vial ,&nbsp;Salvatore Cozzi ,&nbsp;Matteo Coppotelli ,&nbsp;Klaudia Krzekotowska ,&nbsp;Lisa Milan ,&nbsp;Francesco Pupillo ,&nbsp;Stefano Presilla ,&nbsp;Thomas Zilli","doi":"10.1016/j.phro.2026.100977","DOIUrl":"10.1016/j.phro.2026.100977","url":null,"abstract":"<div><div>This study compared knowledge-based and deep-learning dose prediction models with clinically approved plans for prostate radiotherapy with focal boosting. The knowledge-based model accurately reproduced clinical plans. Deep-learning predictions showed median variations of 5% (IQR &lt; 5%) for bladder and rectum in high-dose regions and 3.8 Gy higher mean dose (IQR 1.2 Gy) for the femoral heads. However, pudendal artery mean doses were 15 Gy higher (IQR: 10–19 Gy) and urethral V_62.4Gy exceeded 50%, above the 2% constraint, likely reflecting their absence in the training dataset. While deep-learning models provide a consistent spatial framework for plan optimization, expert review remains essential.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"39 ","pages":"Article 100977"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147805793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An evaluation of uncertainty quantification methods and measures for deep learning outcome prediction models in head and neck cancer radiotherapy","authors":"Daniel C. MacRae ,&nbsp;Luuk van der Hoek ,&nbsp;Joëlle E. van Aalst ,&nbsp;Suzanne P.M de Vette ,&nbsp;Robert van der Wal ,&nbsp;Hendrike Neh ,&nbsp;Baoqiang Ma ,&nbsp;Nanna M. Sijtsema ,&nbsp;Matias A. Valdenegro-Toro ,&nbsp;Peter M.A. van Ooijen ,&nbsp;Lisanne V. van Dijk","doi":"10.1016/j.phro.2026.100978","DOIUrl":"10.1016/j.phro.2026.100978","url":null,"abstract":"<div><h3>Background and Purpose</h3><div>Deep learning (DL) outcome prediction models show promise in radiotherapy but face limited clinical adoption due to concerns about prediction reliability. Although uncertainty quantification (UQ) can provide confidence estimates alongside predictions, there is currently little consensus on appropriate UQ approaches for DL-based outcome prediction. This study therefore evaluates and compares different UQ approaches for normal tissue complication probability (NTCP) and tumour control probability (TCP) models in head and neck cancer.</div></div><div><h3>Materials and Methods</h3><div>Four published DL models were reproduced: two NTCP models predicting xerostomia and dysphagia at six months post-treatment, and two TCP models predicting two-year survival and locoregional control. Three UQ methods—Monte Carlo dropout, deep ensembles, and test-time augmentation—and three uncertainty measures—predictive entropy, variance, and mutual information—were evaluated. Models were retrained on development sets (NTCP: 964 patients, TCP: 255 patients), and assessed on independent validation sets (NTCP: 241 patients, TCP: 85 patients) using discriminative performance, calibration metrics, and sparsification analysis.</div></div><div><h3>Results</h3><div>Incorporating UQ methods maintained comparable discriminative performance to baseline models across all endpoints (mean AUC: 0.72–0.73 vs 0.72). Deep ensembles and Monte Carlo dropout demonstrated strong calibration between uncertainty values and prediction accuracy, while test-time augmentation showed variable reliability. Entropy and variance consistently correlated with prediction accuracy, whereas mutual information proved unstable.</div></div><div><h3>Conclusions</h3><div>Monte Carlo dropout and deep ensembles provide meaningful uncertainty estimates for NTCP and TCP prediction without compromising model performance. These methods show potential for selective prediction workflows where high-confidence predictions guide treatment decisions while uncertain cases are flagged.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"39 ","pages":"Article 100978"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147805656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure visibility and online adaptation suitability of a new high-performance ring-gantry cone-beam computed tomography imaging system in thoracic radiotherapy","authors":"Agustinus J.A.J. van de Schoot,&nbsp;Joan J. Penninkhof,&nbsp;Britt Kunnen,&nbsp;Kimm P. Fremeijer,&nbsp;Elise M. Nicolai – Koornneef,&nbsp;Kirsten Offereins - van Harten,&nbsp;Judith H. Sluijter,&nbsp;Nienke D. Sijtsema,&nbsp;Marjan van de Pol,&nbsp;Raymond de Boer,&nbsp;Maarten L.P. Dirkx,&nbsp;Steven F. Petit","doi":"10.1016/j.phro.2026.100984","DOIUrl":"10.1016/j.phro.2026.100984","url":null,"abstract":"<div><h3>Background and purpose</h3><div>A recently introduced high-performance ring-gantry cone-beam computed tomography (CBCT_H) imaging system promises superior image quality compared with conventional ring-gantry CBCT imaging (CBCT_C), however, it incurs additional costs. Our aim was to determine the added value of CBCT_H compared with CBCT_C in thoracic radiotherapy by quantifying structure visibility and online adaptive radiotherapy (oART) suitability.</div></div><div><h3>Materials and methods</h3><div>Twenty lung cancer patients treated in free-breathing and twenty left-sided breast cancer patients treated in deep-inspiration breath-hold were included in this prospective clinical study. Three CBCT imaging pairs per patient, consisting of CBCT_H and CBCT_C acquired on consecutive days, were included. Four observers independently scored all 240 CBCT datasets on structure visibility and oART suitability (1–5 scale). The effect of respiratory motion management on image quality enhancement was determined by comparing cohort-specific score differences.</div></div><div><h3>Results</h3><div>In total, 4440 structure visibility and 960 oART suitability scores were collected. Patient-averaged scores favored CBCT_H in 82% (100%) of the cases in the lung (breast) cohort. Compared with CBCT_C, CBCT_H-based scores increased significantly (p &lt; 0.05) in both cohorts for structure visibility (lung: 2.8 to 3.1; breast: 3.1 to 3.8) and oART suitability (lung: 2.6 to 2.9; breast: 3.1 to 3.9). Structure visibility (oART suitability) score differences increased with deep-inspiration breath-hold (p &lt; 0.001) compared with free-breathing, by on average 0.38 (0.39).</div></div><div><h3>Conclusion</h3><div>In thoracic radiotherapy, CBCT_H yielded statistically significant improvements in structure visibility and oART suitability where the largest improvements were obtained for CBCT_H in deep-inspiration breath-hold. These results can contribute to informed decision-making regarding cost-effectiveness of CBCT_H.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"39 ","pages":"Article 100984"},"PeriodicalIF":3.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147805730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}