Physics and Imaging in Radiation Oncology最新文献_第9页

Surface-guided breathing signal integration in breathing-adapted intelligent 4D computed tomography: prototype implementation and comparison with an infrared marker-based system 呼吸适应智能四维计算机断层扫描中的表面引导呼吸信号集成：原型实现和与基于红外标记的系统的比较

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100848

Niklas A. Lackner , Torsten Moser , Julian Young , Jannis Dickmann , Volker That , Christian Hofmann , Andre Karius , Mushawar Ahmad , Oliver J. Ott , Florian Putz , Rainer Fietkau , Christoph Bert , Juliane Szkitsak

Background and purpose

Breathing-adapted intelligent four-dimensional computed tomography (i4DCT) reduces motion artifacts during irregular breathing using real-time surrogate signal analysis to control X-ray timing. Current implementations rely on infrared (IR) markers or pressure belts. Surface-guided radiation therapy (SGRT), a widely used markerless technique in radiotherapy, has not been evaluated for direct i4DCT integration. This study tested SGRT for i4DCT acquisition in a phantom setup and benchmarked it against an infrared marker-based system.

Materials and methods

Phantom measurements with clinically relevant regular and irregular breathing signals were performed on a prototype CT scanner with direct SGRT control. To improve SGRT-based surrogate accuracy, a table motion correction profile was empirically modeled, and a vendor-specific prediction algorithm was implemented. Surrogate signal accuracy, latency, and motion reconstruction accuracy were compared between SGRT and an established IR system using amplitude- and phase-based reconstructions.

Results

SGRT exhibited an absolute latency of ∼ 63 ms, compared to ∼ 23 ms for the IR system. Across regular and irregular breathing signals, SGRT breathing signals showed Root Mean Square Error (RMSE) values up to ∼ 1.5 mm, while correlation with the ideal signal remained high (r = 1). Tumor center-of-mass deviations in amplitude-based reconstructions reached 1.5 mm without prediction at 20 breaths-per-minute and 15 mm amplitude, but reduced to < 0.5 mm with 50 ms prediction. Both amplitude- and phase-based reconstructions showed improved agreement with ideal motion when prediction was applied, with phase-based reconstructions yielding better accuracy.

Conclusions

These findings support SGRT as a clinically viable non-contact alternative to IR tracking in i4DCT, especially when combined with motion correction and predictive modeling.

背景和目的适应呼吸的智能四维计算机断层扫描（i4DCT）通过实时替代信号分析来控制x射线时间，减少不规则呼吸期间的运动伪影。目前的实现依赖于红外（IR）标记或压力带。表面引导放射治疗（SGRT）是一种广泛应用于放射治疗的无标记物技术，但尚未对其与i4DCT的直接结合进行评估。本研究在模拟装置中测试了SGRT用于i4DCT采集，并将其与基于红外标记的系统进行了基准测试。材料和方法在直接SGRT控制的原型CT扫描仪上测量与临床相关的规则和不规则呼吸信号。为了提高基于sgrt的代理精度，对表运动校正轮廓进行了经验建模，并实现了特定于供应商的预测算法。比较了SGRT和基于振幅和相位重建的IR系统的替代信号精度、延迟和运动重建精度。结果ssgrt的绝对延迟为~ 63 ms，而IR系统的绝对延迟为~ 23 ms。在规则和不规则呼吸信号中，SGRT呼吸信号的均方根误差（RMSE）值高达1.5 mm，而与理想信号的相关性仍然很高（r = 1）。当呼吸次数为每分钟20次，振幅为15mm时，基于振幅重建的肿瘤质心偏差在没有预测的情况下达到1.5 mm，但在预测50ms时，肿瘤质心偏差降至0.5 mm。当应用预测时，基于振幅和相位的重建都显示出与理想运动的一致性，基于相位的重建产生更好的精度。这些发现支持SGRT作为临床可行的非接触式替代IR跟踪的i4DCT，特别是当结合运动校正和预测建模时。

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引用次数: 0

A multi-centre evaluation of deep learning based radiotherapy planning for left-sided node-negative breast cancer 基于深度学习的左侧淋巴结阴性乳腺癌放疗计划的多中心评价

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-09-22 DOI: 10.1016/j.phro.2025.100839

Marlie Besouw , Niels van Acht , Dave van Gruijthuijsen , Thérèse van Nunen , Jorien van der Leer , Maurice van der Sangen , Jacqueline Theuws , Jean-Paul Kleijnen , Antoinette Verbeek-de Kanter , Chrysi Papalazarou , Marcelle Immink , Roel Kierkels , Coen Hurkmans

Background and Purpose

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.

Materials and Methods

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.

Results

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.

Conclusion

DLP with a standardised translation parameter set demonstrated general applicability across multiple institutions.

背景与目的基于深度学习的放射治疗计划（DLP）具有提高放射治疗计划一致性和效率的潜力。然而，其临床适用性仍然有限，部分原因是需要将预测剂量转化为可交付剂量。本研究通过评估其性能和开发标准化翻译参数集，评估了跨多个机构的特定机构DLP解决方案的通用性。材料与方法4家机构对15例左侧淋巴结阴性乳腺癌患者提供临床治疗方案。使用基于某机构数据训练的深度学习预测模型生成提供40.05 Gy的治疗方案。通过将初始参数设置（InitialMimick）应用于来自其他三个机构的数据集（n = 45），使用国家共识标准进行外部验证。然后根据来自所有四家机构的数据（n = 12）开发标准化参数集（GenericMimick），然后对数据集中剩余的48名患者进行评估。结果initialmimick计划在Dmean （40.5 vs. 40.1 Gy）和D2% （42.4 vs. 41.4 Gy）的计划目标体积中显示更高的平均剂量值，与临床计划（25/45）相比，达到所有临床目标（15/45）的病例较少。经过参数调整后，GenericMimick计划导致更多的计划达到所有目标（28/48），与临床计划（30/48）相当，Dmean为40.3 vs. 40.1 Gy， D2%为41.9 vs. 41.5 Gy。有危险器官的平均差异平均剂量小于0.2戈瑞。结论具有标准化翻译参数集的dlp在多个机构中具有普遍适用性。

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引用次数: 0

A novel respiratory surrogate system with table motion correction and visual feedback for computed tomography 一种具有桌面运动校正和视觉反馈的新型呼吸替代系统

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-09-19 DOI: 10.1016/j.phro.2025.100836

Niklas Andre Lackner , Janis Langkrär , Andre Karius , Oliver J. Ott , Rainer Fietkau , Christoph Bert , Juliane Szkitsak

Background and purpose

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.

Materials and methods

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.

Results

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.

Conclusion

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.

背景与目的CT放射治疗中呼吸运动的管理是至关重要的。临床替代系统和视觉指导可能由于桌面移动或凹陷而出现不准确性，限制了深度吸气屏气（DIBH） CT和四维CT （4DCT）的有效性。本研究评估了一种运动矫正的新型替代和反馈系统，以改善DIBH和4DCT呼吸质量。材料和方法反馈系统在增加载荷（高达104 kg）下的工作台凹陷补偿模拟试验中进行了评估。对患者进行DIBH平台稳定性指标（n = 2）和4DCT基线偏移（n = 3）的评估。在一项志愿者研究中（n = 10），比较DIBH和4DCT情景下的音频和视觉反馈，分别评估屏气稳定性和呼吸规律性。结果在假体测量中，在最大负荷下，工作台凹陷对呼吸信号的影响有效降低，基线移位限制在- 0.2 mm，而在临床系统中可达- 5 mm。在患者中，该系统改善了DIBH信号的稳定性，反映在平台漂移上（- 0.2 mm/s vs. - 0.8 mm/s），与临床系统（- 1.7±0.3 mm）相比，该系统大大减少了4DCT的基线漂移（- 0.2±0.2 mm）。志愿者测试表明，视觉反馈改善了DIBH的再现性（标准偏差：0.5 mm vs.音频反馈1.1 mm）。在4DCT场景中，视觉反馈统一了不规则呼吸者，但没有提供比音频指导一致的改善。结论该系统补偿了幻影、患者和志愿者的桌面运动测量。在反馈场景下，它在DIBH中表现良好，而在4DCT中的性能需要进一步优化。

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引用次数: 0

Development and characterization of phantoms to investigate the Flash effect with Drosophila melanogaster at an ultra-high dose rate radiotherapy linac 研究超高剂量率直线放射治疗下黑腹果蝇的闪效应

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-09-15 DOI: 10.1016/j.phro.2025.100835

Riccardo Dal Bello , Marvin Kreuzer , Irene Vetrugno , Jamie C. Little , Rafael Kranzer , Stefan Schischke , Lily Bossin , Eduardo Gardenali Yukihara , Matthias Guckenberger , Martin Pruschy , Stephanie Tanadini-Lang

Background and purpose

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 Drosophila melanogaster, i.e. the fruit fly.

Materials and methods

A clinical linear accelerator was modified to deliver 16 MeV electron beams in UHDR and conventional (CONV) mode. Two phantoms were developed to irradiate Drosophila melanogaster. 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.

Results

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 Drosophila 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.

Conclusions

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.

背景与目的超高剂量率放射治疗因其闪光效应而拓宽了治疗窗口。实验性线性加速器已转换为超高dr，以收集临床前证据。增加可及性、吞吐量和研究额外的生物端点是破解Flash效应机制的关键。本研究的目的是开发和表征一个用果蝇（即果蝇）进行UHDR实验的实验平台。材料和方法对一种临床直线加速器进行了改进，使其能够在UHDR和常规（CONV）模式下输出16 MeV的电子束。两个幻影被开发用来照射黑腹果蝇。表征是基于主动（超薄离子室原型，闪烁体）和被动探测器（放射性变色薄膜，OSLD）。此外，利用额外的专用模体研究了超高压光子的超高dr能力。结果电子UHDR辐照的平均剂量率为200 ~ 7500 Gy/s。单瓶内光束空间均匀性优于±5%。以不同形态和光束方式给黑腹果蝇的剂量确认为±5%水平。光子特高压辐射的平均剂量率达到40 Gy/s以上。结论：该高通量实验平台在经过改装的临床线性加速器上，可用于比较CONV和UHDR，每周最多500只动物，生物终点高达1000 Gy。在一个改装的临床直线加速器上，也首次证明了光子巨压UHDR辐射的产生。

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引用次数: 0

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 带静态端口和动态准直的旋转电弧治疗降低了食管癌患者的心肺剂量，并降低了基于模型的质子治疗的预测获益

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-09-04 DOI: 10.1016/j.phro.2025.100833

Pieter Populaire , Gilles Defraene , Karel Aerts , Truus Reynders , Wout Piot , Bianca Vanstraelen , Karin Haustermans , Wouter Crijns

Background and purpose

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).

Materials and methods

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 > 10 %) was assessed.

Results

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 < 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 < 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 < 0.01 compared to RAD). RAD reduced the predicted pulmonary complication risk versus IMRT on average 7 % (p < 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 < 0.01). Model-based PT-referral was indicated for nine IMRT-plans versus only five RAD-plans.

Conclusion

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.

背景和目的减少对肺和心脏的剂量对于减少食管癌患者接受三位一体治疗的毒性至关重要。本研究比较了一种结合旋转弧线、静态光束角度和动态准直（RAD）的新技术与标准调强放疗（IMRT）和质子治疗（PT）的效果。材料和方法为来自PROTECT试验的10例患者创建了rad计划，这些患者在临床imrt计划中具有较高的平均肺剂量。对于所有技术，优化优先考虑肺保留。使用经过验证的ntcp模型估计预测的肺并发症风险。对IMRT、RAD和PT进行比较，并评估对基于模型的PT转诊的影响（ΔNTCP > 10%）。结果与IMRT相比，rad降低了平均肺剂量（中位数10.2 Gy [8.3-12.5 Gy]比12.0 Gy [10.2 - 16.3 Gy], p < 0.01），同时也降低了平均心脏剂量（中位数24.1 Gy [20.9-25.0 Gy]比25.7 Gy [21.9-26.1 Gy], p < 0.01）。PT达到了最大的节约，平均肺剂量降至5.1 Gy [2.8-7.1 Gy]，平均心脏剂量降至9.8 Gy [6.4-13.6 Gy]（与RAD相比p <； 0.01）。与IMRT相比，RAD预测肺部并发症的风险平均降低7% (p < 0.01)，个别患者ΔNTCPs的范围从2%到19%不等。PT提供了进一步的好处，与RAD相比，平均ΔNTCP减少11% （p < 0.01）。9个imrt计划有基于模型的pt转诊，而rad计划只有5个。结论与IMRT相比，rad降低了食管癌三段式治疗患者的肺和心脏剂量，降低了肺部并发症的预测风险，影响了pt转诊的决定。

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引用次数: 0

Exploring hypoxia in head and neck cancer through blood perfusion and metabolism using dual-energy computed tomography and positron emission tomography 应用双能计算机断层扫描和正电子发射断层扫描通过血液灌注和代谢研究头颈部肿瘤缺氧

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-07-01 DOI: 10.1016/j.phro.2025.100824

Jens Edmund , Christian Maare , Henriette Klitgaard Mortensen , Kristin Skougaard , Camilla Kjaer Lonkvist , Laura Ann Rechner

Background and purpose

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.

Materials and methods

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,

\frac{σ_{IC}}{\bar{IC}}

, 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

\frac{\frac{σ_{I C}}{\bar{I C}}}{% S U V_{\max}}

. The perfusion and metabolism metrics were further applied in a consumption and supply-based hypoxia (CSH) model.

Results

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 >0.75 supporting the CSH model.

Conclusions

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.

背景与目的头颈癌（HNC）缺氧可以用正电子发射断层扫描（PET）使用18f -氟唑霉素-阿拉伯糖（FAZA）成像，但不常规使用。相比之下，氟脱氧葡萄糖（FDG） PET显示肿瘤代谢通常用于HNC患者的放射治疗（RT）。双能计算机断层扫描（DECT）可以生成碘浓度（IC）图，显示灌注血容量。在这里，我们探讨了如何使用PET衍生的FDG和DECT衍生的IC指标对HNC进行缺氧分类。材料与方法收集6例HNC患者在放疗前及放疗期间的DECT、FAZA、FDG PET/CT。采用FAZA肿瘤与肌肉（TMR）比值≥1.2进行缺氧分类。在总肿瘤体积（GTV）范围内，用IC标准差除以平均比值σICIC¯来模拟血液灌注，用最大FDG标准摄取值百分比（%SUVmax）来模拟代谢活性。分别计算模型血灌注和代谢的受试者工作特征（ROC），并用σICIC¯%SUVmax计算。灌注和代谢指标进一步应用于基于消耗和供应的缺氧（CSH）模型。结果结合血液灌注和代谢指标，roc曲线改善，AUC在0.9左右。具有高代谢活性和低模拟血灌注的gtv以低氧组分为主>；0.75支持CSH模型。结论结合DECT和FDG PET衍生指标建立的血液灌注和代谢模型作为潜在的缺氧生物标志物具有优越的预测能力，这可能与CSH模型有关。

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引用次数: 0

Quantifying movement of optical structures during radiotherapy treatment for tumors near the orbita 眼眶附近肿瘤放射治疗中光学结构运动的量化

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-07-01 DOI: 10.1016/j.phro.2025.100830

Femke Vaassen, David Hofstede, Nikolina Birimac, Inge Compter, Marlies Granzier, Wouter van Elmpt, Catharina M.L. Zegers, Daniëlle B.P. Eekers

Background and purpose

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.

Materials and methods

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.

Results

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.

Conclusions

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.

背景与目的眼眶附近肿瘤放射治疗过程中光学结构的移动可能影响放射量，从而影响副作用的发生。因此，本研究的目的是量化放射治疗期间光学结构的运动。材料与方法回顾性分析20例脑肿瘤患者，在没有注视指导的情况下进行计划CT扫描（pCT）和5例重复CT扫描（reCTs）。双侧六个光学结构：晶状体、角膜、视网膜、泪腺、黄斑和视神经（ON）。联合国分为三个次区域。计算pCT和reCT之间的骰子相似系数（DSC）、绝对距离（AD）和3D中点差（ΔMP），计算90%患者覆盖95%体积的计划风险体积（PRV）边缘和各向同性扩张。对神经和鼻咽肿瘤进行了剂量-体积原理证明。结果角膜最高中位ΔMP为1.9 mm。对于ON亚区域，最高中位数和95百分位数ΔMP为近端眶内ON: 1.3 mm和3.1 mm。ON的中位AD最高：3.0 mm（负z方向）。睁眼状态导致ON、颅内ON和近端眶内ON的DSC较低，而近端眶内ON的DSC较高ΔMP。独立结构需要1-4毫米的各向同性膨胀，这取决于典型的运动范围。神经系统的剂量差异大于鼻咽部计划。结论观察到的光学结构运动提示临床应考虑prv切缘。在治疗过程中要求病人闭上眼睛可以减少他们的活动。

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引用次数: 0

Multiparametric magnetic resonance imaging for radiotherapy response evaluation in high-risk soft tissue sarcoma: A pilot study 多参数磁共振成像对高危软组织肉瘤放疗反应的评价：一项初步研究

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-07-01 DOI: 10.1016/j.phro.2025.100818

Milan van Meekeren , Petra J. van Houdt , Marta Fiocco , Jessica M. Winfield , Christina Messiou , Birthe C. Heeres , Hans Gelderblom , Neeltje Steeghs , Rick Haas , Kirsten van Langevelde

Background and purpose

Soft tissue sarcomas (STS) are rare mesenchymal tumors for which no clinically validated quantitative magnetic resonance imaging (qMRI) parameters exist yet.

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.

Materials and methods

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.

Results

RC was 0.17 × 10^-3 mm²/s for ADC and %RC was, 5 % and 65 % for T₂ and K^trans, respectively.

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.

Conclusion

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.

背景与目的软组织肉瘤（STS）是一种罕见的间充质肿瘤，临床上尚没有有效的定量磁共振成像（qMRI）参数。本研究探讨了局部高风险STS在新辅助血管生成抑制（口服帕唑帕尼）和放疗期间和之后qMRI参数的可重复性及其与组织病理学的关系。材料和方法对15例患者的qMRI参数，包括表观扩散系数（ADC）、体积传递常数（Ktrans）和T2松弛时间，在基线（B1和B2）、新辅助治疗和术前分别获得两次。对于所有三个参数，确定每个肿瘤的平均值。然后根据B1和B2的平均值评估重复性系数（RC或%RC）。估计混合模型来研究组织病理学活细胞百分比与ADC平均值的基线绝对变化（ΔqMRI）以及T2和Ktrans在每个时间点的基线变化百分比（%ΔqMRI）之间的关系。结果ADC的RC值为0.17 × 10-3 mm2/s， T2和Ktrans的RC值分别为5%和65%。平均ADC和T2的变化在各时间点均呈上升和下降趋势，而平均Ktrans以下降为主。ADC平均值为ΔqMRI， T2平均值为%ΔqMRI， Ktrans平均值为%ΔqMRI，与活细胞百分比无统计学意义关联。本初步研究报告了ADC和T2的重复性系数相对较低，而Ktrans的重复性系数较高，并且在15例STS患者中显示了qMRI参数的异质性变化，但这些参数与活细胞百分比之间没有相关性。

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引用次数: 0

Comparison of stereotactic photon and proton treatment plans for metastasis-directed radiotherapy 转移性放射治疗中立体定向光子与质子治疗方案的比较

IF 3.4 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-07-01 DOI: 10.1016/j.phro.2025.100808

Rans Kato, De Roover Robin, De Meerleer Gert, Haustermans Karin, Berghen Charlien, Poels Kenneth

Background and purpose

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.

Materials & methods

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 > 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.

Results

Volumetric Modulated Arc Therapy (VMAT) and Intensity Modulated Proton Therapy (IMPT) achieved a satisfactory BED₃ > 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 < 0.001). IMPT provided significant organs at risk (OAR) sparing, making it a promising modality for reducing long-term toxicities.

Conclusion

Proton therapy may reduce long-term treatment-related toxicities and be more effective for re-irradiation. It achieves a satisfactory BED₃ of > 100 Gy in more patients as photon therapy with a statistically significant advantage in voxel wise minimum GTV D_99%.

背景和目的在转移导向治疗（MDT）中，实现最佳局部控制是延迟进一步转移扩散的关键。生物等效剂量（BED）和局部控制之间的明确相关性，当BED超过100 Gy时，使用α:β比为3，其率达到99%，强调了研究先进辐射方式的重要性。材料,方法对20例38个病灶的患者进行放射计划研究，比较光子和质子立体定向放射治疗对少进展性转移性去势难治性前列腺癌患者的疗效。主要目的是确定质子治疗是否达到了令人满意的BED3。与光子治疗相比，在尊重危险器官的剂量限制的情况下，使用体素最小剂量的100 Gy治疗更多的患者。结果体积调节电弧治疗（VMAT）和强度调节质子治疗（IMPT）达到了令人满意的BED3 >；100戈瑞的病例分别为75%和78%。在元音最小总肿瘤体积（GTV） D99% (p <；0.001)。IMPT提供了重要的危险器官（OAR）保留，使其成为减少长期毒性的有希望的方式。结论质子治疗可减少长期治疗相关的毒副作用，对再照射更有效。达到了令人满意的BED3 >；在100 Gy以上的患者中，光子治疗在体素最小GTV D99%方面具有统计学上显著的优势。

{"title":"Comparison of stereotactic photon and proton treatment plans for metastasis-directed radiotherapy","authors":"Rans Kato, De Roover Robin, De Meerleer Gert, Haustermans Karin, Berghen Charlien, 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 & 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 BED<sub>3</sub> of > 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 BED<sub>3</sub> > 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<sub>99%</sub> (p < 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 BED<sub>3</sub> of > 100 Gy in more patients as photon therapy with a statistically significant advantage in voxel wise minimum GTV D<sub>99%</sub>.</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}

引用次数: 0

Hybrid proton planning combining spread-out Bragg peak beams with transmission beams to shorten field delivery times while maintaining plan quality 混合质子计划结合了展开的布拉格峰值光束和传输光束，在保持计划质量的同时缩短了现场交付时间

IF 3.4 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-07-01 DOI: 10.1016/j.phro.2025.100809

Roni Hytönen , Reynald Vanderstraeten , Wilko F.A.R. Verbakel

Background and purpose

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.

Materials and methods

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.

Results

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 %).

Discussion

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.

背景与目的基于bragg峰的强度调制质子治疗场的递送时间对患者的吞吐量和舒适度起着重要的作用。尽管有相关的出口剂量，单层质子传输光束受益于更锐利的半影，并且传输速度极快。在本研究中，我们调查了在使用两种现场类型时，现场交付时间（FDT）和计划质量的权衡。材料与方法采用内部自动迭代优化器对8例左侧乳腺癌患者和10例口咽癌患者制定参考治疗方案。针对每种情况创建了比较混合计划。对于乳房，不同的组合传输和传统光束进行了评估。对于口咽，三个传统光束中的两个被六个传输光束取代。通过将剂量指标和FDT与参考方案进行比较来评估混合方案。结果与参考方案相比，混合方案具有器官危险（OAR）的平均剂量和最大剂量，靶剂量的均匀性和一致性，而fdt的中位数（四分位数间距）下降了58% /166 s（56 - 61%）。与参考计划相比，混合口咽计划显示出更高的平均OAR剂量，特别是口腔（中位数为34 Gy vs 31 Gy）和脊髓（20 Gy vs 11 Gy），而FDTs降低了73% /91 s（71 - 73%）。根据具体情况，混合规划可以显著减少总FDT，而对计划质量的影响有限。减少的总FDT可以改善患者的舒适度，减少治疗的总持续时间，并改善多室中心的光束调度。

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引用次数: 0