Physics and Imaging in Radiation Oncology最新文献

{"title":"Multiomic random forest toxicity modeling of radiation esophagitis","authors":"Saurabh S. Nair ,&nbsp;Ramon M. Salazar ,&nbsp;Ting Xu ,&nbsp;Alexandra O. Leone ,&nbsp;Zhongxing Liao ,&nbsp;Laurence E. Court ,&nbsp;Joshua S. Niedzielski","doi":"10.1016/j.phro.2025.100838","DOIUrl":"10.1016/j.phro.2025.100838","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Radiation esophagitis (RE) is a major dose-limiting toxicity resulting from radiotherapy for non-small-cell lung cancer (NSCLC). Multiomic features may provide additional predictive value for high-grade RE compared to traditionally used clinical and dose-volume histogram (DVH) parameters. We aimed to investigate the utility of multiomic features in improving RE toxicity prediction models.</div></div><div><h3>Materials and methods</h3><div>Of the 179 NSCLC patients considered, 27 patients (15.08 %) were found to have toxicity ≥grade 3 RE per CTCAE v5.0. A total of 343 CT- and PET- based radiomic and dosiomic features were extracted. Four toxicity prediction models were created using clinical factors and features from one of the following groups: (a) base model (DVH), (b) radiomic, (c) dosiomic, and (d) combined radiomic and dosiomic. Models were developed using a random forest classifier with 100 Monte Carlo cross-validation iterations and an 80 %/20 % training/test split. Model predictive performance was evaluated by area under the receiver operating characteristic curve (AUC) and area under the precision-recall curve (AUPRC).</div></div><div><h3>Results</h3><div>The AUC and AUPRC values (mean ± standard deviation) for the 4 model types were 0.69 ± 0.10/0.42 ± 0.12 (base model), 0.71 ± 0.12/0.48 ± 0.13 (radiomic), 0.73 ± 0.10/0.48 ± 0.15 (dosiomic), and 0.75 ± 0.10/0.49 ± 0.14 (radiomic and dosiomic), respectively. The bootstrap percentile method, which was used to compare performance metrics between multiomic and base models, showed that the combined model was the best performing model type.</div></div><div><h3>Conclusion</h3><div>All multiomic models outperformed the base model. The combined radiomic-dosiomic model provides novel insights into high-grade RE risk and may inform future strategies for toxicity mitigation and personalized treatment planning.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100838"},"PeriodicalIF":3.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221818","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 multi-centre evaluation of deep learning based radiotherapy planning for left-sided node-negative breast cancer","authors":"Marlie Besouw ,&nbsp;Niels van Acht ,&nbsp;Dave van Gruijthuijsen ,&nbsp;Thérèse van Nunen ,&nbsp;Jorien van der Leer ,&nbsp;Maurice van der Sangen ,&nbsp;Jacqueline Theuws ,&nbsp;Jean-Paul Kleijnen ,&nbsp;Antoinette Verbeek-de Kanter ,&nbsp;Chrysi Papalazarou ,&nbsp;Marcelle Immink ,&nbsp;Roel Kierkels ,&nbsp;Coen Hurkmans","doi":"10.1016/j.phro.2025.100839","DOIUrl":"10.1016/j.phro.2025.100839","url":null,"abstract":"<div><h3>Background and Purpose</h3><div>Deep learning based planning (DLP) has the potential to improve consistency and efficiency in radiotherapy treatment planning. However, its clinical applicability remains limited, partly due to the need to translate a predicted dose into a deliverable dose. This study evaluated the generalisability of an institution specific DLP solution across multiple institutions by assessing its performance and developing a standardised translation parameter set.</div></div><div><h3>Materials and Methods</h3><div>Four institutions provided clinical treatment plans of 15 patients with left-sided node-negative breast cancer. Treatment plans delivering 40.05 Gy were generated using a deep learning prediction model trained on data from one institution. External validation was performed using national consensus criteria, by applying the initial parameter settings (InitialMimick) to datasets (n = 45) from three other institutions. A standardised parameter set (GenericMimick) was then developed based on data (n = 12) from all four institutions, whereafter it was evaluated on the remaining 48 patients of the dataset.</div></div><div><h3>Results</h3><div>InitialMimick plans showed higher average dose values in the planning target volume for the D_mean (40.5 vs. 40.1 Gy) and D_2% (42.4 vs. 41.4 Gy), with fewer cases meeting all clinical goals (15/45) compared to clinical plans (25/45). After parameter adjustment, GenericMimick plans resulted in more plans meeting all goals (28/48), comparable to the clinical plans (30/48), with D_mean of 40.3 vs. 40.1 Gy and D_2% of 41.9 vs. 41.5 Gy. Mean differences in organs at risk mean doses were less than 0.2 Gy.</div></div><div><h3>Conclusion</h3><div>DLP with a standardised translation parameter set demonstrated general applicability across multiple institutions.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100839"},"PeriodicalIF":3.3,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119440","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 respiratory surrogate system with table motion correction and visual feedback for computed tomography","authors":"Niklas Andre Lackner ,&nbsp;Janis Langkrär ,&nbsp;Andre Karius ,&nbsp;Oliver J. Ott ,&nbsp;Rainer Fietkau ,&nbsp;Christoph Bert ,&nbsp;Juliane Szkitsak","doi":"10.1016/j.phro.2025.100836","DOIUrl":"10.1016/j.phro.2025.100836","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Managing respiratory motion is crucial for computed tomography (CT) in radiotherapy. Clinical surrogate systems and visual coaching can exhibit inaccuracies due to table motion or sag, limiting effectiveness in deep inspiration breath-hold (DIBH) CT and four-dimensional CT (4DCT). This study evaluated a motion-corrected novel surrogate and feedback system to improve DIBH and 4DCT breathing quality.</div></div><div><h3>Materials and methods</h3><div>The feedback system was evaluated in phantom tests for table sag compensation under incremental loads (up to 104 kg). For patients, DIBH plateau stability metrics (n = 2) and baseline shifts in 4DCT (n = 3) were assessed. In a volunteer study (n = 10), audio and visual feedback were compared in DIBH and 4DCT scenarios, assessing breath-hold stability and breathing regularity, respectively.</div></div><div><h3>Results</h3><div>In phantom measurements, the impact of table sag on the breathing signal was effectively reduced at maximum load, with baseline shifts limited to −0.2 mm, compared to up to −5 mm in clinical systems. In patients, the system improved DIBH signal stability, as reflected in the plateau drift (−0.2 mm/s vs. −0.8 mm/s), and substantially reduced baseline shifts in 4DCT (−0.2 ± 0.2 mm) when compared to clinical systems (−1.7 ± 0.3 mm). Volunteer tests demonstrated improved DIBH reproducibility with visual feedback (standard deviation: 0.5 mm vs. 1.1 mm with audio feedback). In 4DCT scenarios, visual feedback unified irregular breathers but offered no consistent improvement over audio guidance.</div></div><div><h3>Conclusion</h3><div>The novel system compensated for table motion in phantom, patient, and volunteer measurements. In feedback scenarios, it performed well in DIBH, while its performance in 4DCT requires further optimization.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100836"},"PeriodicalIF":3.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119441","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":"Development and characterization of phantoms to investigate the Flash effect with Drosophila melanogaster at an ultra-high dose rate radiotherapy linac","authors":"Riccardo Dal Bello ,&nbsp;Marvin Kreuzer ,&nbsp;Irene Vetrugno ,&nbsp;Jamie C. Little ,&nbsp;Rafael Kranzer ,&nbsp;Stefan Schischke ,&nbsp;Lily Bossin ,&nbsp;Eduardo Gardenali Yukihara ,&nbsp;Matthias Guckenberger ,&nbsp;Martin Pruschy ,&nbsp;Stephanie Tanadini-Lang","doi":"10.1016/j.phro.2025.100835","DOIUrl":"10.1016/j.phro.2025.100835","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Ultra-high dose rate (UHDR) radiotherapy may widen the therapeutic window thanks to the Flash effect. Experimental linear accelerators have been converted to UHDR to collect pre-clinical evidence. Increasing the accessibility, throughput and investigating additional biological endpoints is key for deciphering the mechanism of the Flash effect. The aim of this study was to develop and characterise an experimental platform for UHDR experiments with <em>Drosophila melanogaster</em>, i.e. the fruit fly.</div></div><div><h3>Materials and methods</h3><div>A clinical linear accelerator was modified to deliver 16 MeV electron beams in UHDR and conventional (CONV) mode. Two phantoms were developed to irradiate <em>Drosophila melanogaster</em>. The characterization was based both on active (ultra-thin ion chamber prototype, scintillator) and passive detectors (radiochromic films, OSLD). Moreover, the UHDR capabilities for megavoltage photon were investigated with an additional dedicated phantom.</div></div><div><h3>Results</h3><div>The electron UHDR irradiations provided average dose rates in the range of 200–––7500 Gy/s. The beam spatial uniformity within a single vial was better than ± 5 %. The dose delivered to <em>Drosophila</em> melanogaster in different configurations and beam modalities was confirmed to the ± 5 % level. The average dose rate achieved with photon megavoltage UHDR radiation reached beyond 40 Gy/s.</div></div><div><h3>Conclusions</h3><div>This high-throughput experimental platform on a converted clinical linear accelerator could be used to compare CONV to UHDR for up to 500 animals per week for biological endpoints at up to 1000 Gy. The production of photon megavoltage UHDR radiation was also demonstrated for the first time at a converted clinical linac.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100835"},"PeriodicalIF":3.3,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145098016","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":"Rotational arc treatments with static ports and dynamic collimation reduces cardiopulmonary dose for esophageal cancer patients and diminishes model-based predicted benefit of proton therapy","authors":"Pieter Populaire ,&nbsp;Gilles Defraene ,&nbsp;Karel Aerts ,&nbsp;Truus Reynders ,&nbsp;Wout Piot ,&nbsp;Bianca Vanstraelen ,&nbsp;Karin Haustermans ,&nbsp;Wouter Crijns","doi":"10.1016/j.phro.2025.100833","DOIUrl":"10.1016/j.phro.2025.100833","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Reducing dose to the lungs and heart is essential to minimize toxicity in esophageal cancer patients undergoing trimodality therapy. This study compared a new technique combining rotational arcs, static beam angles and dynamic collimation (RAD) against standard intensity-modulated radiotherapy (IMRT) and proton therapy (PT).</div></div><div><h3>Materials and methods</h3><div>RAD-plans were created for ten patients from the PROTECT trial who had high mean lung doses in their clinical IMRT-plan. For all techniques, optimization prioritized lung sparing. Predicted pulmonary complication risks were estimated using a validated NTCP-model. Comparisons were made between IMRT, RAD, and PT, and the impact on model-based PT-referral (ΔNTCP &gt; 10 %) was assessed.</div></div><div><h3>Results</h3><div>RAD lowered mean lung dose compared with IMRT (median 10.2 Gy [range 8.3–12.5 Gy] versus 12.0 Gy [10.2–16.3 Gy], p &lt; 0.01) and also incidentally reduced mean heart dose (median 24.1 Gy [20.9–25.0 Gy] versus 25.7 Gy [21.9–26.1 Gy], p &lt; 0.01). PT achieved the greatest sparing, with mean lung dose reduced to 5.1 Gy [2.8–7.1 Gy] and mean heart dose to 9.8 Gy [6.4–13.6 Gy] (both p &lt; 0.01 compared to RAD). RAD reduced the predicted pulmonary complication risk versus IMRT on average 7 % (p &lt; 0.01), with individual patient ΔNTCPs ranging from 2 % to 19 %. PT offered further benefit, with an additional average ΔNTCP reduction of 11 % compared to RAD (p &lt; 0.01). Model-based PT-referral was indicated for nine IMRT-plans versus only five RAD-plans.</div></div><div><h3>Conclusion</h3><div>RAD reduced lung and heart dose compared to IMRT in esophageal cancer patients undergoing trimodality treatment, lowering predicted risk for pulmonary complications, which influenced PT-referral decisions.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100833"},"PeriodicalIF":3.3,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047863","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":"Exploring hypoxia in head and neck cancer through blood perfusion and metabolism using dual-energy computed tomography and positron emission tomography","authors":"Jens Edmund ,&nbsp;Christian Maare ,&nbsp;Henriette Klitgaard Mortensen ,&nbsp;Kristin Skougaard ,&nbsp;Camilla Kjaer Lonkvist ,&nbsp;Laura Ann Rechner","doi":"10.1016/j.phro.2025.100824","DOIUrl":"10.1016/j.phro.2025.100824","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Hypoxia for head and neck cancer (HNC) can be imaged with positron emission tomography (PET) using ¹⁸F-Fluoroazomycin-arabinoside (FAZA) but is not used routinely. In contrast, fluorodeoxyglucose (FDG) PET visualizing tumor metabolism is routinely used in radiotherapy (RT) of HNC patients. Dual-energy computed tomography (DECT) can generate an iodine concentration (IC) map visualizing the perfused blood volume. Here, we explore how hypoxia can be classified for HNC using a PET derived FDG and a DECT derived IC metric.</div></div><div><h3>Materials and methods</h3><div>Corresponding DECT, FAZA, and FDG PET/CT for 6 HNC patients before and during RT were acquired. A FAZA tumor-to-muscle (TMR) ratio ≥1.2 was used for hypoxic classification. Within the gross tumor volume (GTV), the IC standard deviation over mean ratio, <span><math><mfrac><msub><mi>σ</mi><mrow><mi>IC</mi></mrow></msub><mover><mrow><mi>IC</mi></mrow><mrow><mo>¯</mo></mrow></mover></mfrac></math></span>, was used to model blood perfusion and the percentage of maximum FDG standard uptake value (%SUV_max) was used for metabolic activity. Receiver Operating Characteristics (ROC) was performed for the modelled blood perfusion and metabolism individually and combined as <span><math><mfrac><mfrac><msub><mi>σ</mi><mrow><mi>I</mi><mi>C</mi></mrow></msub><mover><mrow><mi>I</mi><mi>C</mi></mrow><mo>¯</mo></mover></mfrac><mrow><mo>%</mo><mi>S</mi><mi>U</mi><msub><mi>V</mi><mi>max</mi></msub></mrow></mfrac></math></span>. The perfusion and metabolism metrics were further applied in a consumption and supply-based hypoxia (CSH) model.</div></div><div><h3>Results</h3><div>ROC curves improved with AUC around 0.9 when combining the blood perfusion and metabolism metrics. GTVs with high metabolic activity and and low modelled blood perfusion was dominated by hypoxic fractions &gt;0.75 supporting the CSH model.</div></div><div><h3>Conclusions</h3><div>Combining blood perfusion and metabolism modelled from DECT and FDG PET derived metrics resulted in a superior predictive power as potential hypoxia biomarkers which might be explained by a CSH model.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"35 ","pages":"Article 100824"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144864778","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":"Quantifying movement of optical structures during radiotherapy treatment for tumors near the orbita","authors":"Femke Vaassen,&nbsp;David Hofstede,&nbsp;Nikolina Birimac,&nbsp;Inge Compter,&nbsp;Marlies Granzier,&nbsp;Wouter van Elmpt,&nbsp;Catharina M.L. Zegers,&nbsp;Daniëlle B.P. Eekers","doi":"10.1016/j.phro.2025.100830","DOIUrl":"10.1016/j.phro.2025.100830","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Movement of optical structures during radiotherapy for tumors near the orbita might affect the amount of radiation given and consequently the risk for side effects. The aim of this study was therefore to quantify motion of optical structures during radiotherapy.</div></div><div><h3>Materials and methods</h3><div>Twenty brain tumor patients were retrospectively included, with planning computed tomography (CT)-scan (pCT) and five repeat-CT-scans (reCTs) without gazing instructions. Six optical structures were delineated bilaterally: lens, cornea, retina, lacrimal glands, macula, and optic nerves (ON). The ON was split in three subregions. The dice similarity coefficient (DSC), absolute distance (AD), and difference in 3D midpoint (ΔMP) were calculated between pCT and reCT. Planning risk volume (PRV)-margins and isotropic expansions to cover 95 % volume for 90 % patients were calculated. A dose-volume proof-of-principle was performed for a neurological and nasopharyngeal tumor.</div></div><div><h3>Results</h3><div>Highest median ΔMP was found for the cornea: 1.9 mm. For ON subregions, highest median and 95th-percentile ΔMP was found for proximal intra-orbital ON: 1.3 mm and 3.1 mm. ON showed highest median AD: 3.0 mm (negative Z-direction). Open eyelid status resulted in statistically significant lower DSC for ON, intra-cranial ON, and proximal intra-orbital ON, and higher ΔMP for proximal intra-orbital ON. 1–4 mm isotropic expansions were needed for separate structures, dependent on typical movement range. Higher dose-differences were found for the neurological than the nasopharyngeal plan.</div></div><div><h3>Conclusions</h3><div>The observed movement of optical structures indicated that a PRV-margin should be considered in clinical practice. Asking the patient to close their eyes during the treatment could decrease the movement.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"35 ","pages":"Article 100830"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144987833","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":"Multiparametric magnetic resonance imaging for radiotherapy response evaluation in high-risk soft tissue sarcoma: A pilot study","authors":"Milan van Meekeren ,&nbsp;Petra J. van Houdt ,&nbsp;Marta Fiocco ,&nbsp;Jessica M. Winfield ,&nbsp;Christina Messiou ,&nbsp;Birthe C. Heeres ,&nbsp;Hans Gelderblom ,&nbsp;Neeltje Steeghs ,&nbsp;Rick Haas ,&nbsp;Kirsten van Langevelde","doi":"10.1016/j.phro.2025.100818","DOIUrl":"10.1016/j.phro.2025.100818","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Soft tissue sarcomas (STS) are rare mesenchymal tumors for which no clinically validated quantitative magnetic resonance imaging (qMRI) parameters exist yet.</div><div>This study explores repeatability and association with histopathology of qMRI parameters during and after neo-adjuvant angiogenesis inhibition (oral pazopanib) and radiotherapy for localized, high-risk STS.</div></div><div><h3>Materials and methods</h3><div>For fifteen patients, qMRI parameters, including apparent diffusion coefficient (ADC), volume transfer constant (K^trans) and T₂ relaxation times were acquired twice at baseline (B1 and B2), twice during neo-adjuvant treatment and pre-surgery. For all three parameters, the mean was determined per tumor. Subsequently, repeatability coefficient (RC or %RC) was assessed from B1 and B2 mean values. Mixed models were estimated to study the association between percentage viable cells from histopathology and absolute change from baseline (ΔqMRI) for ADC mean and percentage change from baseline (%ΔqMRI) for T₂ and K^trans at each time point.</div></div><div><h3>Results</h3><div>RC was 0.17 × 10^-3 mm²/s for ADC and %RC was, 5 % and 65 % for T₂ and K^trans, respectively.</div><div>The changes in mean ADC and T₂ showed both increases and decreases at each timepoint, whereas mean K^trans predominantly showed decreases. ΔqMRI for ADC mean, %ΔqMRI for T₂ mean and %ΔqMRI for K^trans mean showed no statistically significant association with % viable cells.</div></div><div><h3>Conclusion</h3><div>This pilot study reported relatively low repeatability coefficients for ADC and T₂ and a higher repeatability coefficient for K^trans and showed heterogeneous changes in qMRI parameters in fifteen STS patients, however with no association between these parameters and percentage viable cells.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"35 ","pages":"Article 100818"},"PeriodicalIF":3.3,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144772926","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 stereotactic photon and proton treatment plans for metastasis-directed radiotherapy","authors":"Rans Kato,&nbsp;De Roover Robin,&nbsp;De Meerleer Gert,&nbsp;Haustermans Karin,&nbsp;Berghen Charlien,&nbsp;Poels Kenneth","doi":"10.1016/j.phro.2025.100808","DOIUrl":"10.1016/j.phro.2025.100808","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Achieving optimal local control is pivotal in the context of metastasis-directed therapy (MDT) in delaying further metastatic spread. The clear correlation between the biological equivalent dose (BED) and local control, with rates reaching 99 % when BED exceeds 100 Gy using an α:β ratio of 3, underlines the importance of investigating advanced radiation modalities.</div></div><div><h3>Materials &amp; methods</h3><div>A planning study was conducted in 20 patients treated for 38 lesions to compare photon based and proton based stereotactic radiation therapy in oligoprogressive metastatic castration-refractory prostate cancer patients. The primary objective was to determine whether proton therapy is achieving a satisfactory BED₃ of &gt; 100 Gy using the voxel wise minimum dose in more patients when compared with photon therapy respecting the dose constraints for the organs-at-risk.</div></div><div><h3>Results</h3><div>Volumetric Modulated Arc Therapy (VMAT) and Intensity Modulated Proton Therapy (IMPT) achieved a satisfactory BED₃ &gt; 100 Gy in 75 % and 78 % of the cases, respectively. A significance difference was observed in favor of IMPT for vowel-wise minimum gross tumor volume (GTV) D_99% (p &lt; 0.001). IMPT provided significant organs at risk (OAR) sparing, making it a promising modality for reducing long-term toxicities.</div></div><div><h3>Conclusion</h3><div>Proton therapy may reduce long-term treatment-related toxicities and be more effective for re-irradiation. It achieves a satisfactory BED₃ of &gt; 100 Gy in more patients as photon therapy with a statistically significant advantage in voxel wise minimum GTV D_99%.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"35 ","pages":"Article 100808"},"PeriodicalIF":3.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144654223","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":"Hybrid proton planning combining spread-out Bragg peak beams with transmission beams to shorten field delivery times while maintaining plan quality","authors":"Roni Hytönen ,&nbsp;Reynald Vanderstraeten ,&nbsp;Wilko F.A.R. Verbakel","doi":"10.1016/j.phro.2025.100809","DOIUrl":"10.1016/j.phro.2025.100809","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Delivery times of Bragg-peak-based intensity-modulated proton therapy fields play an important role in patient throughput and comfort. Despite the associated exit dose, single-layer proton transmission beams benefit from sharper penumbras and are extremely fast to deliver. In this study, we investigated the trade-offs in field delivery times<!--> <!-->(FDT) and plan quality when using both field types.</div></div><div><h3>Materials and methods</h3><div>Reference treatment plans were created for eight left-sided breast and ten oropharynx cancer patients using an in-house automatic iterative optimizer. Comparative hybrid plans were created for each case. For breast, different combinations of transmission and conventional beams were evaluated. For oropharynx, two of the three conventional beams were replaced with six transmission beams. Hybrid plans were evaluated by comparing the dose metrics and FDT against the reference plans.</div></div><div><h3>Results</h3><div>Hybrid breast plans exhibited mean and maximum organ at risk (OAR) doses, and target dose homogeneity and conformity comparable to the reference plans, while their FDTs decreased by median (interquartile range) of 58 %/166 s (56–61 %). Compared to reference plans, hybrid oropharynx plans exhibited higher mean OAR dose especially to oral cavity (median of 34 Gy vs 31 Gy) and spinal cord (20 Gy vs 11 Gy), while FDTs decreased by 73 %/91 s (71–73 %).</div></div><div><h3>Discussion</h3><div>Depending on the case, hybrid planning can significantly reduce total FDT with only limited impact on plan quality. The reduced total FDT can improve patient comfort, reduce overall duration of the treatment, and improve beam scheduling at multi-room centers.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"35 ","pages":"Article 100809"},"PeriodicalIF":3.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144654222","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}