Physics and Imaging in Radiation Oncology最新文献

{"title":"Comparing methods to improve cone-beam computed tomography for dose calculations in adaptive proton therapy","authors":"Casper Dueholm Vestergaard ,&nbsp;Nadine Vatterodt ,&nbsp;Ulrik Vindelev Elstrøm ,&nbsp;Kenneth Jensen ,&nbsp;Ole Nørrevang ,&nbsp;Ludvig Paul Muren ,&nbsp;Stine Sofia Korreman ,&nbsp;Vicki Trier Taasti","doi":"10.1016/j.phro.2025.100784","DOIUrl":"10.1016/j.phro.2025.100784","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Proton therapy requires dose monitoring, often performed based on repeated computed tomography (reCT) scans. However, reCT scans may not accurately reflect the internal anatomy and patient positioning during treatment. In-room cone-beam CT (CBCT) offers a potential alternative, but its low image quality limits proton dose calculation accuracy. This study therefore evaluated different methods for quality-improvement of CBCTs (synthetic CTs; sCTs) for use in adaptive proton therapy of head-and-neck cancer patients.</div></div><div><h3>Materials and methods</h3><div>Thirty-five CBCTs from twenty-four head-and-neck cancer patients were used to assess four sCT generation methods: an intensity-correction method, two deformable image registration methods, and a deep learning-based method. The sCTs were evaluated against same-day reCTs for CT number accuracy, proton range accuracy through single-spot plans, and dose recalculation accuracy of clinical plans via dose-volume-histogram (DVH) parameters.</div></div><div><h3>Results</h3><div>All four methods generated sCTs with improved image quality while preserving the anatomy relative to the CBCT. The differences in absolute median proton range between sCT methods were small and generally less than the difference between sCT and reCT, which had median differences of 1.0–1.1 mm. Similarly, differences in DVH parameters were generally small between the sCT methods. While outliers were identified for all four methods, these outliers were often consistent for all sCT methods and could be attributed to anatomical and/or positional discrepancies between the CBCT and reCT.</div></div><div><h3>Conclusions</h3><div>All four sCT methods enabled accurate proton dose calculation and preserved the anatomy, making them of value for adaptive proton therapy.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"34 ","pages":"Article 100784"},"PeriodicalIF":3.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144088929","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":"Knowledge-based model for automated multi-isocenter total marrow and lymphoid irradiation planning across standard and large patient anatomies","authors":"Manuela Meraldi ,&nbsp;Nicola Lambri ,&nbsp;Damiano Dei ,&nbsp;Piera Navarria ,&nbsp;Giacomo Reggiori ,&nbsp;Ciro Franzese ,&nbsp;Stefano Tomatis ,&nbsp;Cristina Lenardi ,&nbsp;Marta Scorsetti ,&nbsp;Pietro Mancosu","doi":"10.1016/j.phro.2025.100781","DOIUrl":"10.1016/j.phro.2025.100781","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Total marrow and lymphoid irradiation (TMLI) planning is challenging. This study evaluates whether a knowledge-based (KB) model for TMLI delivered using volumetric modulated arc therapy (VMAT) can achieve clinically acceptable dose distributions through fully or semi-automated optimization and whether a single model is effective across varying patient anatomies.</div></div><div><h3>Materials and methods</h3><div>Fifty-one consecutive VMAT-TMLI patients were selected. A KB model was trained using 30 patients treated with standard configurations (5 body isocenters). Validation included two cohorts: 10 standard patients and 11 patients with a larger anatomy treated using separate isocenters for the arms (4 body and 2 arms isocenters). Two planning approaches were explored: fully automated (AutoKB), and KB with manual adjustments (HybridKB) by a planner with no prior experience in TMLI. KB plans were evaluated against clinical plans (CPs) using paired t-tests.</div></div><div><h3>Results</h3><div>The KB model reduced mean doses to major organs-at-risk (OARs). For standard configurations, mean OAR doses were 71% ± 2%, 66% ± 2%, and 66% ± 2% for CP, AutoKB, and HybridKB (both p &lt; 0.01). For larger patients, the corresponding values were 75% ± 3%, 69% ± 2%, and 68% ± 2% (both p &lt; 0.01). D2% of the planning target volume increased in AutoKB, reaching 122% ± 2% (p &lt; 0.001) vs. 117% ± 3% in CP for standard configurations, and 126% ± 2% (p &lt; 0.001) vs. 117% ± 3% in CP for arms configurations. HybridKB was on par with CPs.</div></div><div><h3>Conclusions</h3><div>A single KB model enabled effective planning for multi-isocenter TMLI, including anatomies requiring separate isocenters for the arms. Fully automated KB provided suboptimal dose distributions. KB with manual refinements reduced planner dependence and improved plan quality.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"34 ","pages":"Article 100781"},"PeriodicalIF":3.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144123138","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":"Feasibility of prompt gamma verification for cone-beam computed tomography-based online adaptive proton therapy","authors":"Stefanie Bertschi ,&nbsp;Kristin Stützer ,&nbsp;Jonathan Berthold ,&nbsp;Ulrik Elstrøm ,&nbsp;Anne Vestergaard ,&nbsp;Giuliano Perotti Bernardini ,&nbsp;Gabriel Marmitt ,&nbsp;Guillaume Janssens ,&nbsp;Julian Pietsch ,&nbsp;Stefan Both ,&nbsp;Stine Korreman ,&nbsp;Christian Richter","doi":"10.1016/j.phro.2025.100778","DOIUrl":"10.1016/j.phro.2025.100778","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Prompt-gamma based <em>in vivo</em> treatment verification, such as prompt-gamma imaging (PGI), is crucial for detecting anatomical changes and serving as safety net during proton therapy treatments. This is especially important in an online-adaptive setting, when imaging will be based on cone-beam computed tomography (CBCT). This study investigated whether PGI, proven effective to detect relevant anatomical changes in clinical settings, can also verify treatment plans adapted on CBCTs, particularly the reliability of CBCT-based PGI-simulations of expected prompt-gamma distributions, a key requirement for PGI-based verification.</div></div><div><h3>Material and methods</h3><div>For a homogeneous and anthropomorphic phantom, a fan-beam computed tomography (CT) and a CBCT were acquired. Corrected CBCT and virtual CT datasets were generated. PGI simulations and independent dose calculations were performed on the different CBCT datasets and compared to the fan-beam CT, extracting PGI-based and integrated-depth-dose (IDD)-based range-shifts. For three head-and-neck cancer patients, PGI-based shifts between the fan-beam CT and a synthetic CT (from a daily CBCT) were compared to line-dose-based shifts from clinical dose calculations.</div></div><div><h3>Results</h3><div>For the homogeneous phantom, all CBCT datasets enabled adequate PGI simulations, with PGI-based shifts correlating very closely with IDD-based shifts. For the anthropomorphic phantom and the three patient datasets, observed PGI-based shifts were correlated to IDD-based shifts.</div></div><div><h3>Conclusions</h3><div>For phantom and patient data, PGI simulations depended mainly on the reliability of depth-dose distributions on the planning image with negligible uncertainties from PG emission. For CBCT-based OAPT, correct depth-dose distributions are required. Hence, PGI is also a promising treatment verification tool for CBCT-based OAPT.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"34 ","pages":"Article 100778"},"PeriodicalIF":3.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143941761","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":"Transmission beam planning for improved robustness and efficiency in proton therapy for head and neck cancer","authors":"Alessandro Vai ,&nbsp;Alfredo Mirandola ,&nbsp;Vittoria Pavanello ,&nbsp;Giuseppe Magro ,&nbsp;Matteo Bagnalasta ,&nbsp;Luca Trombetta ,&nbsp;Anna Maria Camarda ,&nbsp;Rossana Ingargiola ,&nbsp;Sara Ronchi ,&nbsp;Anna Cavallo ,&nbsp;Marzia Franceschini ,&nbsp;Andrea Riccardo Filippi ,&nbsp;Nicola Alessandro Iacovelli ,&nbsp;Mario Ciocca ,&nbsp;Ester Orlandi","doi":"10.1016/j.phro.2025.100777","DOIUrl":"10.1016/j.phro.2025.100777","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Optimizing head and neck cancer (HNC) plans with single-energy proton beams that fully traverse the patient (transmission beams) can improve robustness and delivery efficiency, complementing conventional approaches.</div></div><div><h3>Materials and Methods</h3><div>Experimental measurements, validated with Monte Carlo (MC) simulations, were carried out on a uniform water-equivalent plastic phantom (RW3) containing a metal component (2-Euro coins) irradiated with a single high energy proton field (228.6 MeV) to verify the transmission beam concept. 28 nasopharyngeal cancer (NPC) intensity modulated proton therapy (IMPT) were then optimized with nine coplanar single-energy fields (228.6 MeV), positioning the Bragg peaks well beyond the patient body, so called transmission beam mode. These plans (IMPT-TB) were compared to conventional IMPT and volumetric modulated arc therapy (VMAT) photon plans in terms of dose distributions quality, expected organ at risk (OAR) toxicity, robustness and delivery time.</div></div><div><h3>Results</h3><div>Transmission beams minimized dose perturbation by metal objects (∼7% max relative variation at 18 cm depth). IMPT-TB plans achieved comparable dose distribution and expected toxicities to IMPT, increasing the dose bath (+96 % vs. IMPT) but remaining significantly lower than VMAT (−31.4 %). For 94 % of patients (N = 26), IMPT-TB met at least one additional dose constraint that the corresponding IMPT plan failed to satisfy. Moreover, in the analyzed subgroup (N = 5), IMPT-TB plans delivered with our synchrotron exhibit a 67 % reduction in beam time compared to IMPT plans.</div></div><div><h3>Conclusions</h3><div>IMPT-TB plans demonstrated enhanced robustness and significantly faster delivery compared to IMPT. Transmission beams could be clinically implemented, also in conjunction with standard IMPT, for proton radiation treatment of NPC.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"34 ","pages":"Article 100777"},"PeriodicalIF":3.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143941194","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":"Uncertainty-guided pancreatic tumor auto-segmentation with Tversky ensemble","authors":"Cenji Yu ,&nbsp;Skylar S. Gay ,&nbsp;Aashish C. Gupta ,&nbsp;Rachael M. Martin-Paulpeter ,&nbsp;Ethan B. Ludmir ,&nbsp;Yao Zhao ,&nbsp;Jack Duryea ,&nbsp;Xinru Chen ,&nbsp;Carlos E. Cardenas ,&nbsp;Jinzhong Yang ,&nbsp;Albert C. Koong ,&nbsp;Tucker J. Netherton ,&nbsp;Dong Joo Rhee ,&nbsp;Laurence E. Court","doi":"10.1016/j.phro.2025.100740","DOIUrl":"10.1016/j.phro.2025.100740","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Pancreatic gross tumor volume (GTV) delineation is challenging due to their variable morphology and uncertain ground truth. Previous deep learning-based auto-segmentation methods have struggled to handle tasks with uncertain ground truth and have not accommodated stylistic customizations. We aim to develop a human-in-the-loop pancreatic GTV segmentation tool using Tversky ensembles by leveraging uncertainty estimation techniques.</div></div><div><h3>Material and methods</h3><div>In this study, we utilized a total of 282 patients from the pancreas task of the Medical Segmentation Decathlon. Thirty patients were randomly selected to form an independent test set, while the remaining 252 patients were divided into an 80–20 % training-validation split. We incorporated Tversky loss layer during training to train a five-member segmentation ensemble with varying contouring tendencies. The Tversky ensemble predicted probability maps by estimating pixel-level segmentation uncertainties. Probability thresholding was employed on the resulting probability maps to generate the final contours, from which eleven contours were extracted for quantitative evaluation against ground truths, with variations in the threshold values.</div></div><div><h3>Results</h3><div>Our Tversky ensemble achieved DSC of 0.47, HD95 of 12.70 mm and MSD of 3.24 mm respectively using the optimal thresholding configuration. We outperformed the Swin-UNETR configuration that achieved the state-of-the-art result in the pancreas task of the medical segmentation decathlon.</div></div><div><h3>Conclusions</h3><div>Our study demonstrated the effectiveness of employing an ensemble-based uncertainty estimation technique for pancreatic tumor segmentation. The approach provided clinicians with a consensus probability map that could be fine-tuned in line with their preferences, generating contours with greater confidence.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"34 ","pages":"Article 100740"},"PeriodicalIF":3.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143829421","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":"Spot-optimization reduces beam delivery time in liver breath hold intensity modulated proton therapy","authors":"Michael Butkus ,&nbsp;Daniel Bastawros ,&nbsp;Yunze Yang ,&nbsp;Roberto Cassetta ,&nbsp;Roni Hytonen ,&nbsp;Robert Kaderka","doi":"10.1016/j.phro.2025.100763","DOIUrl":"10.1016/j.phro.2025.100763","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Liver irradiations with intensity-modulated proton therapy (IMPT) often require motion mitigation techniques that prolong treatment. A prototype spot-optimization algorithm was tested to evaluate whether plan delivery time could be reduced while preserving quality.</div></div><div><h3>Methods and materials</h3><div>Fifteen patients previously treated with liver IMPT using breath-hold were re-planned with nominal treatment planning system (TPS) settings and using a prototype spot-optimization algorithm in which combinations of minimum Monitor Unit (MU) and layer-spacing settings were tested: 1MU/1MeV, 3MU/3MeV, 1MU/5MeV, 5MU/3MeV. Spot-optimized and nominals plans were compared using standard dose-volume histogram (DVH) metrics for targets and organs-at-risk. A Wilcoxon signed-rank test was applied (p &lt; 0.05). Delivery time for all plans were measured by creating and delivering IMPT quality assurance (QA) plans. Gamma analyses were performed on all plans to test deliverability. Plans were considered deliverable if &gt;90 % of points passed a gamma criterion of 3 %/3mm.</div></div><div><h3>Results</h3><div>Minimal DVH differences were observed between nominal and spot-optimized plans. For the 3MU/3MeV setting, no DVH metrics were significantly different. Median and interquartile range (IQR) delivery times for these plans were 40 % (38 %<strong>–</strong>44 %) faster than nominal plans. 5MU/3MeV plans had median (IQR) delivery times 59 % (52 %<strong>–</strong>61 %) faster than nominal plans but had a small but significant increase in Liver_Eff D_mean with a median (IQR) difference of 0.2 Gy(RBE) (0.0<strong>–</strong>0.4 Gy(RBE)). QA analysis showed all spot-optimized plans were deliverable.</div></div><div><h3>Conclusions</h3><div>The spot-optimization algorithm produced clinically deliverable plans with negligible DVH differences to nominal plans and reduced delivery time of liver IMPT by over one-third.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"34 ","pages":"Article 100763"},"PeriodicalIF":3.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The value of post radiotherapy prostate specific antigen dynamics for prostate cancer risk stratification models","authors":"Jane Shortall ,&nbsp;Eliana Vasquez Osorio ,&nbsp;Andrew Green ,&nbsp;Kimberley Reeves ,&nbsp;David Wong ,&nbsp;Tanuj Puri ,&nbsp;Peter Hoskin ,&nbsp;Ananya Choudhury ,&nbsp;Marcel van Herk ,&nbsp;Alan McWilliam","doi":"10.1016/j.phro.2025.100787","DOIUrl":"10.1016/j.phro.2025.100787","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Risk-stratification at diagnosis of prostate cancer does not always predict risk of biochemical recurrence (BCR). Fully utilizing post-radiotherapy follow-up Prostate Specific Antigen (PSA) data could offer earlier and higher prognostic value than pre-treatment risk-stratification.</div><div>We investigate whether PSA dynamics in the first three-years of follow-up can re-stratify risk of treatment failure after radical radiotherapy, allowing for targeted intervention.</div></div><div><h3>Materials and methods</h3><div>Retrospective analysis of repeat follow-up PSA measurements from men with mixed-risk prostate cancer treated in two separate radical radiotherapy techniques (n = 446, 2005–2007). PSA trajectories were modelled between zero and three-years follow-up using Gaussian Process regression. Models were sampled and clustered using hierarchical clustering to define characteristic post-radiotherapy PSA trajectories.</div><div>Kaplan-Meier analysis compared dichotomising by pre-treatment risk-group and characteristic PSA trajectory. Cox proportional-hazard models with and without follow-up PSA information compared using Akaike Information Criterion (AIC).</div></div><div><h3>Results</h3><div>PSA trajectories were characterized as stable, steady-rise, and unstable. Kaplan-Meier analysis showed that pre-treatment risk-group was not prognostic of BCR (p &gt; 0.05), however characteristic PSA trajectory was (p &lt; 0.001). PSA trajectory improved multivariable model performance when added to baseline prognostic variables. Unstable PSA had highest BCR.</div><div>Results were validated across two cohorts and sensitivity analysis, suggesting results were robust. However, analysis excluded patients with BCR within three-years follow-up due to lack of data.</div></div><div><h3>Conclusion</h3><div>PSA dynamics within the first three-years of post-radiotherapy follow-up for prostate cancer were more prognostic of BCR than pre-treatment risk-groups, suggesting PSA dynamics could be used to re-stratify BCR risk during early follow-up.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"34 ","pages":"Article 100787"},"PeriodicalIF":3.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144134589","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":"Cost-effectiveness of personalized policies for implementing organ-at-risk sparing adaptive radiation therapy in head and neck cancer","authors":"Seyedmohammadhossein Hosseinian ,&nbsp;Daniel Suarez-Aguirre ,&nbsp;Cem Dede ,&nbsp;Raul Garcia ,&nbsp;Lucas McCullum ,&nbsp;Mehdi Hemmati ,&nbsp;Aysenur Karagoz ,&nbsp;Abdallah S.R. Mohamed ,&nbsp;Stephen Y. Lai ,&nbsp;Katherine A. Hutcheson ,&nbsp;Amy C. Moreno ,&nbsp;Kristy K. Brock ,&nbsp;Fatemeh Nosrat ,&nbsp;Clifton D. Fuller ,&nbsp;Andrew J. Schaefer","doi":"10.1016/j.phro.2025.100772","DOIUrl":"10.1016/j.phro.2025.100772","url":null,"abstract":"<div><h3>Background and Purpose</h3><div>The principle of adaptive radiation therapy (ART) is to adjust radiation plans in response to anatomical changes during treatment. The purpose of this study was to develop a decision-making model for implementation of personalized ART that balances the costs and clinical benefits of radiation plan adaptations in head and neck cancer (HNC).</div></div><div><h3>Materials and Methods</h3><div>Using retrospective imaging data from 52 HNC patients, a Markov decision process (MDP) model was developed to determine optimal timing for plan adaptations based on the difference in normal tissue complication probability (ΔNTCP) between planned and delivered doses to organs-at-risk. To capture the trade-off between the costs and benefits of plan adaptations, the end-treatment ΔNTCPs were converted to Quality Adjusted Life Years (QALYs) and then to equivalent monetary values using a willingness-to-pay per QALY parameter.</div></div><div><h3>Results</h3><div>The optimal policies were derived for 96 combinations of willingness-to-pay per QALY (W) and re-planning cost (RC) and validated using Monte Carlo simulation for two representative scenarios: (1) W = $200,000, RC = $1,000; (2) W = $100,000, RC = $2,000. In scenario (1), the MDP model’s policy reduced the probability of excessive toxicity (ΔNTCP ≥ 5 %) to zero (from 0.21 without re-planning) at an average cost of $380 per patient. In scenario (2), it reduced this probability to 0.02 at an average cost of $520 per patient.</div></div><div><h3>Conclusions</h3><div>The MDP model’s policies outperformed the current fixed-time (one-size-fits-all) approaches in both clinical and financial outcomes in the simulations.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"34 ","pages":"Article 100772"},"PeriodicalIF":3.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143928939","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 0.05 mm3 diode-based single charged-particle real-time radiation detector for electron radiotherapy","authors":"Kyoungtae Lee ,&nbsp;Rahul Lall ,&nbsp;Michel M. Maharbiz ,&nbsp;Mekhail Anwar","doi":"10.1016/j.phro.2025.100762","DOIUrl":"10.1016/j.phro.2025.100762","url":null,"abstract":"<div><div>Real-time radiation monitoring at the single-particle level is an unmet need for electron radiotherapy, especially for dose deposition to targets in motion or critical OARs. We have developed a first-in-class CMOS-based 0.05 mm³ single electron sensitive detector. The chiplet integrates all the requisite electronics. The functionality of the system is verified under 6 and 9 MeV clinical electron beams. Percentage depth vs. pulse-width curves for 6 and 9 MeV beams are measured and verified using Monte-Carlo simulations. The proposed system has the potential to enhance the electron radiotherapy quality and safety, providing real-time dosimetry from multiple sites simultaneously.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"34 ","pages":"Article 100762"},"PeriodicalIF":3.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Partial adaptation for online-adaptive proton therapy triggered by during-delivery treatment verification: Feasibility study on prostate cancer treatments","authors":"Virginia Gambetta ,&nbsp;Victoria Pieta ,&nbsp;Jonathan Berthold ,&nbsp;Tobias Hölscher ,&nbsp;Albin Fredriksson ,&nbsp;Christian Richter ,&nbsp;Kristin Stützer","doi":"10.1016/j.phro.2025.100755","DOIUrl":"10.1016/j.phro.2025.100755","url":null,"abstract":"<div><h3>Background and Purpose</h3><div>Online treatment verification during proton therapy delivery may detect deviations due to anatomical changes occurring along the treatment course and trigger immediate intervention, if necessary. We investigated the potential of partial plan adaptation in two-field prostate cancer treatments as a solution for online-adaptive proton therapy (OAPT) after the detection of relevant treatment deviations during the first field delivery.</div></div><div><h3>Materials and Methods</h3><div>In a retrospective study, ten fractions from eight prostate cancer patients with prompt gamma imaging (PGI) detected treatment deviations, which were confirmed on respective in-room control computed tomography (cCT) scans, were considered. For each cCT, a dose-mimicking-based robust partial adaptation reoptimized the second field by considering the suboptimal dose delivery of the first non-adapted, PGI-monitored field. The results were compared to the non-adapted scenario and upfront full adaptation (both fields) in terms of achievable target coverage (prescription: 48 Gy/60 Gy to low-risk/high-risk target) and organ-at-risk (OAR) sparing.</div></div><div><h3>Results</h3><div>Partially adapted plans showed comparable target coverage (median <em>D</em>_98%: 99.9%/98.0% for low-/high-risk target) to fully adapted plans (100.3%/98.7%) and were superior to non-adapted plans (98.7%/94.5%). Achievable OAR sparing was patient-specific depending on the proximity to the target region, but within clinical goals for the partially and fully adapted plans.</div></div><div><h3>Conclusions</h3><div>Partial adaptation triggered mid-delivery of a fraction can still generate plans of comparable conformity to full adaptation, even in the case of plans with only two, opposing fields. A verification-triggered OAPT may therefore become an alternative to upfront OAPT, saving time and imaging dose in fractions without relevant anatomy changes.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"34 ","pages":"Article 100755"},"PeriodicalIF":3.4,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}