Physics and Imaging in Radiation Oncology最新文献_第5页

A cone-beam computed tomography based workflow for online adaptive ultra-hypofractionated radiotherapy of prostate cancer 基于锥束计算机断层的前列腺癌在线自适应超低分割放疗工作流程

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100869

Miriam Eckl , Nour Alfakhori , Marvin Willam , Hans Oppitz , Constantin Dreher , Michael Ehmann , Judit Boda-Heggemann , Frank A. Giordano , Jens Fleckenstein

Background and purpose

Cone beam computed tomography (CBCT)-based approaches for online adaptive radiation therapy (oART) have recently become clinically available for ultra-hypofractionated prostate stereotactic body radiation therapy (SBRT). This work assessed the changes of relevant dose-volume-histogram (DVH) parameters and their robustness against morphologic variations during adaptation.

Materials and methods

Sixteen prostate cancer patients were treated with oART in an SBRT regimen (40 Gy in 5 treatment sessions (Tx) to the clinical target volume (CTV), PACE-B constraints). Two CBCTs were acquired daily: CBCT1 for adaptive planning and CBCT2 after adaptation for position verification. Adapted plans optimized on CBCT1 (ART_CBCT1) were recalculated on CBCT2 (ART_CBCT2) and compared to treatment plans on CBCT1 after image guidance (IGRT_CBCT1) for relevant DVH metrics: V_40Gy(CTV), V_37Gy(bladder), V_36Gy(rectum). Spearman’s rank coefficients r with p-values (5% significance level) were determined to analyze correlations between adaptation time (ΔT) and bladder filling as well as Tx and median prostate volume.

Results

oART improved median V_40Gy(CTV) from 86% in IGRT_CBCT1 to 94% in ART_CBCT2. Inter-fractional prostate swelling (

r_{T x, V o l (p r o s t a t e)} = 0.98, p = 0.005)

was responsible for CTV deviations. Bladder filling (

r_{Δ T, V o l (b l a d d e r)} = 0.34, p = 0.002

) and rectal gas migration during the median adaptation time

Δ T = 24.0 m i n

increased V_37Gy(bladder) from 4.9 cm³ in ART_CBCT1 to 6.5 cm³ in ART_CBCT2 and V_36Gy(rectum) from 0.5 cm³ to 0.6 cm³ and led to 10 constraint violations, each.

Conclusion

Compared to IGRT, daily oART substantially improved CTV coverage. Besides inter-fractional prostate swelling, constraint violations originated from seminal vesicles motion, rectal gas or bladder filling during adaptation. Treatment adaptation times should therefore be minimized whenever possible.

背景和目的基于CBCT的在线适应性放射治疗（oART）方法最近已成为超低分割前列腺立体定向放射治疗（SBRT）的临床应用。本研究评估了相关剂量-体积-直方图（DVH）参数的变化及其对适应过程中形态变化的鲁棒性。材料和方法16例前列腺癌患者接受oART治疗，采用SBRT方案（5个疗程（Tx） 40 Gy至临床靶体积（CTV）， PACE-B限制）。每天获取两个cbct: CBCT1用于自适应规划，CBCT2用于位置验证。在CBCT1上优化的适应方案（ARTCBCT1）在CBCT2 （ARTCBCT2）上重新计算，并与图像引导后CBCT1的治疗方案（IGRTCBCT1）进行相关DVH指标的比较：V40Gy(CTV), V37Gy（膀胱），V36Gy（直肠）。测定Spearman秩系数r， p值为5%（显著性水平），分析适应时间（ΔT）与膀胱充盈、Tx和中位前列腺体积之间的相关性。结果art将中位V40Gy（CTV）从IGRTCBCT1的86%提高到ARTCBCT2的94%。分数阶间前列腺肿胀（rTx,Vol（前列腺）=0.98,p=0.005）是CTV偏差的主要原因。膀胱充盈（rΔT,Vol（膀胱）=0.34,p=0.002）和直肠气体迁移在中位适应时间ΔT=24.0min内使V37Gy（膀胱）从ARTCBCT1的4.9 cm3增加到ARTCBCT2的6.5 cm3, V36Gy（直肠）从0.5 cm3增加到0.6 cm3，各导致10次约束违规。结论与IGRT相比，每日oART显著提高了CTV覆盖率。除前列腺分段间肿胀外，适应过程中精囊运动、直肠充气或膀胱充盈也会导致约束违规。因此，应尽可能缩短治疗适应时间。

{"title":"A cone-beam computed tomography based workflow for online adaptive ultra-hypofractionated radiotherapy of prostate cancer","authors":"Miriam Eckl , Nour Alfakhori , Marvin Willam , Hans Oppitz , Constantin Dreher , Michael Ehmann , Judit Boda-Heggemann , Frank A. Giordano , Jens Fleckenstein","doi":"10.1016/j.phro.2025.100869","DOIUrl":"10.1016/j.phro.2025.100869","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Cone beam computed tomography (CBCT)-based approaches for online adaptive radiation therapy (oART) have recently become clinically available for ultra-hypofractionated prostate stereotactic body radiation therapy (SBRT). This work assessed the changes of relevant dose-volume-histogram (DVH) parameters and their robustness against morphologic variations during adaptation.</div></div><div><h3>Materials and methods</h3><div>Sixteen prostate cancer patients were treated with oART in an SBRT regimen (40Gy in 5 treatment sessions (Tx) to the clinical target volume (CTV), PACE-B constraints). Two CBCTs were acquired daily: CBCT1 for adaptive planning and CBCT2 after adaptation for position verification. Adapted plans optimized on CBCT1 (ART<sub>CBCT1</sub>) were recalculated on CBCT2 (ART<sub>CBCT2</sub>) and compared to treatment plans on CBCT1 after image guidance (IGRT<sub>CBCT1</sub>) for relevant DVH metrics: V<sub>40Gy</sub>(CTV), V<sub>37Gy</sub>(bladder), V<sub>36Gy</sub>(rectum). Spearman’s rank coefficients r with p-values (5% significance level) were determined to analyze correlations between adaptation time (ΔT) and bladder filling as well as Tx and median prostate volume.</div></div><div><h3>Results</h3><div>oART improved median V<sub>40Gy</sub>(CTV) from 86% in IGRT<sub>CBCT1</sub> to 94% in ART<sub>CBCT2</sub>. Inter-fractional prostate swelling (<span><math><mrow><msub><mi>r</mi><mrow><mi>T</mi><mi>x</mi><mo>,</mo><mi>V</mi><mi>o</mi><mi>l</mi><mo>(</mo><mi>p</mi><mi>r</mi><mi>o</mi><mi>s</mi><mi>t</mi><mi>a</mi><mi>t</mi><mi>e</mi><mo>)</mo></mrow></msub><mrow><mo>=</mo><mn>0.98</mn><mo>,</mo><mi>p</mi><mo>=</mo><mn>0.005</mn><mo>)</mo></mrow></mrow></math></span> was responsible for CTV deviations. Bladder filling (<span><math><mrow><msub><mi>r</mi><mrow><mi>Δ</mi><mi>T</mi><mo>,</mo><mi>V</mi><mi>o</mi><mi>l</mi><mo>(</mo><mi>b</mi><mi>l</mi><mi>a</mi><mi>d</mi><mi>d</mi><mi>e</mi><mi>r</mi><mo>)</mo></mrow></msub><mo>=</mo><mn>0.34</mn><mo>,</mo><mi>p</mi><mo>=</mo><mn>0.002</mn></mrow></math></span>) and rectal gas migration during the median adaptation time <span><math><mrow><mi>Δ</mi><mi>T</mi><mo>=</mo><mn>24.0</mn><mspace></mspace><mi>m</mi><mi>i</mi><mi>n</mi></mrow></math></span> increased V<sub>37Gy</sub>(bladder) from 4.9 cm<sup>3</sup> in ART<sub>CBCT1</sub> to 6.5 cm<sup>3</sup> in ART<sub>CBCT2</sub> and V<sub>36Gy</sub>(rectum) from 0.5 cm<sup>3</sup> to 0.6 cm<sup>3</sup> and led to 10 constraint violations, each.</div></div><div><h3>Conclusion</h3><div>Compared to IGRT, daily oART substantially improved CTV coverage. Besides inter-fractional prostate swelling, constraint violations originated from seminal vesicles motion, rectal gas or bladder filling during adaptation. Treatment adaptation times should therefore be minimized whenever possible.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100869"},"PeriodicalIF":3.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145576374","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

Proton radiography interpretation with artificial intelligence for treatment deviation detection in proton therapy 人工智能在质子治疗中诊断治疗偏差的质子x线解译

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100872

Giuliano Perotti Bernardini, Arthur Galapon, Gabriel Guterres Marmitt, Jeffrey Free, Peter van Ooijen, Johannes Langendijk, Stefan Both

Background and purpose

Patient setup errors, anatomical changes, and uncertainties in proton range estimation degrade dose conformity in proton therapy. Adaptive proton therapy (APT) mitigates these deviations by monitoring and adjusting treatment plans. Proton radiography (PR) offers direct proton range information, making it a promising method to detect such deviations. In this study, we developed and evaluated an artificial intelligence (AI) PR tool for automated interpretation and classification of treatment deviations.

Materials and methods

Computed Tomography (CT) scans from 32 head-and-neck cancer patients were synthetically modified to simulate setup errors (±2–4 mm), calibration curve errors (±3–5% for fat/soft tissue, ±7–11% for bone), and anatomical changes (±2–12 mm mimicking weight variations). PR simulations were performed using OpenREGGUI to generate integral depth dose (IDD) curves and range shift maps (RSMs) across 260 × 260 mm² PR fields, resulting in 14,503 RSMs. A convolutional neural network (EfficientNet-v2-M) was trained from scratch for multi-label classification. Performance was evaluated on the synthetic dataset and an independent clinical dataset of 22 patients who underwent plan adaptation.

Results

The CNN classified treatment deviations within one second per image. On the synthetic dataset, it achieved 97% precision, 92% recall, 93% F1-score, and 92% F2-score. On the clinical validation set, it maintained high performance metrics: 86% precision, 88% recall, 86% F1-score, and 87% F2-score, demonstrating strong generalization to clinical scenarios.

Conclusions

The AI-enhanced PR tool enables fast, automated detection of treatment deviations in proton therapy, supporting its integration into APT workflows and online plan adaptation for improved quality assurance.

背景与目的：患者设置错误、解剖改变和质子范围估计的不确定性降低了质子治疗的剂量一致性。适应性质子治疗（APT）通过监测和调整治疗计划来减轻这些偏差。质子放射照相（PR）提供了直接的质子范围信息，使其成为一种很有前途的检测这种偏差的方法。在本研究中，我们开发并评估了用于自动解释和分类治疗偏差的人工智能（AI） PR工具。材料和方法对32例头颈癌患者的CT扫描进行综合修改，模拟设置误差（±2-4 mm）、校准曲线误差（脂肪/软组织±3-5%，骨骼±7-11%）和解剖变化（±2-12 mm模拟体重变化）。利用OpenREGGUI进行PR模拟，生成260 × 260 mm2 PR场的积分深度剂量（IDD）曲线和距离位移图（rsm），得到14503个rsm。从头开始训练卷积神经网络（EfficientNet-v2-M）进行多标签分类。在合成数据集和22名接受计划适应的患者的独立临床数据集上评估性能。结果CNN能在1秒内对每幅图像的处理偏差进行分类。在合成数据集上，它达到了97%的精度，92%的召回率，93%的f1得分和92%的f2得分。在临床验证集上，它保持了很高的性能指标：86%的准确率，88%的召回率，86%的f1得分和87%的f2得分，显示出对临床场景的强泛化。人工智能增强的PR工具可以快速、自动地检测质子治疗的治疗偏差，支持其集成到APT工作流程和在线计划调整中，以提高质量保证。

{"title":"Proton radiography interpretation with artificial intelligence for treatment deviation detection in proton therapy","authors":"Giuliano Perotti Bernardini, Arthur Galapon, Gabriel Guterres Marmitt, Jeffrey Free, Peter van Ooijen, Johannes Langendijk, Stefan Both","doi":"10.1016/j.phro.2025.100872","DOIUrl":"10.1016/j.phro.2025.100872","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Patient setup errors, anatomical changes, and uncertainties in proton range estimation degrade dose conformity in proton therapy. Adaptive proton therapy (APT) mitigates these deviations by monitoring and adjusting treatment plans. Proton radiography (PR) offers direct proton range information, making it a promising method to detect such deviations. In this study, we developed and evaluated an artificial intelligence (AI) PR tool for automated interpretation and classification of treatment deviations.</div></div><div><h3>Materials and methods</h3><div>Computed Tomography (CT) scans from 32 head-and-neck cancer patients were synthetically modified to simulate setup errors (±2–4 mm), calibration curve errors (±3–5% for fat/soft tissue, ±7–11% for bone), and anatomical changes (±2–12 mm mimicking weight variations). PR simulations were performed using OpenREGGUI to generate integral depth dose (IDD) curves and range shift maps (RSMs) across 260 × 260 mm<sup>2</sup> PR fields, resulting in 14,503 RSMs. A convolutional neural network (EfficientNet-v2-M) was trained from scratch for multi-label classification. Performance was evaluated on the synthetic dataset and an independent clinical dataset of 22 patients who underwent plan adaptation.</div></div><div><h3>Results</h3><div>The CNN classified treatment deviations within one second per image. On the synthetic dataset, it achieved 97% precision, 92% recall, 93% F1-score, and 92% F2-score. On the clinical validation set, it maintained high performance metrics: 86% precision, 88% recall, 86% F1-score, and 87% F2-score, demonstrating strong generalization to clinical scenarios.</div></div><div><h3>Conclusions</h3><div>The AI-enhanced PR tool enables fast, automated detection of treatment deviations in proton therapy, supporting its integration into APT workflows and online plan adaptation for improved quality assurance.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100872"},"PeriodicalIF":3.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681035","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

Integrating automated electromagnetic tracking-based needle reconstruction in the intraoperative high-dose-rate prostate brachytherapy workflow 在术中高剂量率前列腺近距离放射治疗工作流程中集成基于自动电磁跟踪的针头重建

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100884

Ioannis Androulakis , Jérémy Godart , Miranda E.M.C. Christianen , Henrike Westerveld , Lorne Luthart , Remi A. Nout , Mischa S. Hoogeman , Inger-Karine K. Kolkman-Deurloo

Background and Purpose

Manual transrectal ultrasound (TRUS) reconstruction, currently used in intraoperative prostate brachytherapy, is error‑prone. Automated implant reconstruction with electromagnetic tracking (EMT) has the potential to improve accuracy. The aim of this study was to implement and validate afterloader‑integrated EMT for automated implant reconstruction.

Materials and Methods

An afterloader prototype equipped with an integrated EMT system was used in conjunction with a TRUS-based treatment planning system and setup. A workflow was developed to transform the EMT measurements into the implant reconstruction and import this into the treatment planning software. The workflow was retrospectively evaluated using clinical data from 14 patients. To align the EMT measurements with the treatment-planning coordinate system without a TRUS-based pre-reconstruction, a novel setup was developed using a single reference sensor integrated into the template holder. The reproducibility and accuracy of the workflow using this latter setup was evaluated in phantom measurements.

Results

The retrospective evaluation revealed that errors in active dwell positions of up to 10.2 mm caused absolute V_100% differences of up to 5.3 % of the target volume, and up to 24.4 %, 2.1 %, and 14.1 % of the prescribed dose for urethra D_0.1cm₃, rectum D_2cm3, and bladder D_1cm3, respectively. In phantom measurements with our novel setup using reference sensor registration, EMT-based reconstruction demonstrated high reproducibility (0.5 mm) and agreement with TRUS-based reconstruction (0.7 mm), requiring a measurement time of < 23 s per implanted needle.

Conclusion

The implementation of EMT-based reconstruction on clinical data shows clinically relevant impact on dose-volume metrics of TRUS-based implant reconstructions errors. Using the novel workflow and hardware, highly accurate and automated implant reconstruction is possible.

背景与目的经直肠超声（TRUS）重建术，目前用于术中前列腺近距离治疗，容易出错。采用电磁跟踪（EMT）的自动植入体重建具有提高准确性的潜力。本研究的目的是实施和验证后装载机集成EMT用于自动种植体重建。材料和方法配备了集成EMT系统的后置装载机原型机与基于tri的处理计划系统和设置一起使用。开发了一个工作流程，将EMT测量转换为植入物重建，并将其导入治疗计划软件。使用14例患者的临床资料对该工作流程进行回顾性评估。为了使EMT测量值与治疗计划坐标系对齐，无需基于tri的预重建，开发了一种新型装置，使用集成在模板支架中的单个参考传感器。使用后一种设置的工作流程的再现性和准确性在模拟测量中进行了评估。结果回顾性评价结果显示，活性驻留位置误差（最大10.2 mm）导致的靶体积绝对V100%差异高达5.3%，尿道D0.1cm3、直肠D2cm3和膀胱D1cm3分别高达24.4%、2.1%和14.1%的处方剂量差异。在我们使用参考传感器配准的新装置进行的假体测量中，基于emt的重建显示出高再现性（0.5 mm），并且与基于trt的重建（0.7 mm）一致，每根植入针需要23秒的测量时间。结论基于emt的种植体重建对临床数据的实施对基于trt的种植体重建误差的剂量-体积指标有临床相关的影响。使用新的工作流程和硬件，高度精确和自动化的植入物重建是可能的。

{"title":"Integrating automated electromagnetic tracking-based needle reconstruction in the intraoperative high-dose-rate prostate brachytherapy workflow","authors":"Ioannis Androulakis , Jérémy Godart , Miranda E.M.C. Christianen , Henrike Westerveld , Lorne Luthart , Remi A. Nout , Mischa S. Hoogeman , Inger-Karine K. Kolkman-Deurloo","doi":"10.1016/j.phro.2025.100884","DOIUrl":"10.1016/j.phro.2025.100884","url":null,"abstract":"<div><h3>Background and Purpose</h3><div>Manual transrectal ultrasound (TRUS) reconstruction, currently used in intraoperative prostate brachytherapy, is error‑prone. Automated implant reconstruction with electromagnetic tracking (EMT) has the potential to improve accuracy. The aim of this study was to implement and validate afterloader‑integrated EMT for automated implant reconstruction.</div></div><div><h3>Materials and Methods</h3><div>An afterloader prototype equipped with an integrated EMT system was used in conjunction with a TRUS-based treatment planning system and setup. A workflow was developed to transform the EMT measurements into the implant reconstruction and import this into the treatment planning software. The workflow was retrospectively evaluated using clinical data from 14 patients. To align the EMT measurements with the treatment-planning coordinate system without a TRUS-based pre-reconstruction, a novel setup was developed using a single reference sensor integrated into the template holder. The reproducibility and accuracy of the workflow using this latter setup was evaluated in phantom measurements.</div></div><div><h3>Results</h3><div>The retrospective evaluation revealed that errors in active dwell positions of up to 10.2 mm caused absolute V<sub>100%</sub> differences of up to 5.3 % of the target volume, and up to 24.4 %, 2.1 %, and 14.1 % of the prescribed dose for urethra D<sub>0.1cm</sub><sub>3</sub>, rectum D<sub>2cm3</sub>, and bladder D<sub>1cm3</sub>, respectively. In phantom measurements with our novel setup using reference sensor registration, EMT-based reconstruction demonstrated high reproducibility (0.5 mm) and agreement with TRUS-based reconstruction (0.7 mm), requiring a measurement time of < 23 s per implanted needle.</div></div><div><h3>Conclusion</h3><div>The implementation of EMT-based reconstruction on clinical data shows clinically relevant impact on dose-volume metrics of TRUS-based implant reconstructions errors. Using the novel workflow and hardware, highly accurate and automated implant reconstruction is possible.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100884"},"PeriodicalIF":3.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681027","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

Individualised dose mapping uncertainty estimation in the reirradiation setting 再照射环境下个体化剂量图不确定度估计

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100881

Chelmis Muthoni Thiong’o , Marcel van Herk , Kathryn Banfill , Clara Chan , Catherine Harris , Matthew Lowe , Tom Marchant , Iskandar Mohamed , Golnoosh Motamedi-Ghahfarokhi , David Thomson , Ane Appelt , Eliana Vasquez Osorio

Background and purpose

Deformable image registration (DIR) allows assessing radiation doses of previous treatment courses in reirradiation planning scans. However, DIR can introduce uncertainties in dose mapping. Estimating these uncertainties for individual patients remains a key challenge. We developed an individualised approach to estimate uncertainties in dose mapping using a commercially available treatment planning system.

Materials and methods

For 54 patients who underwent reirradiation (27 head and neck, H&N, and 27 lung cases), we performed 16 DIRs per patient. We assessed each DIR geometrically using the mean distance to agreement (mDTA) between mapped contours and the corresponding structures of 30 to 34 organs at risk (OARs). We then estimated dose mapping uncertainties for structures where DIR resulted in plausible registrations, defined as mDTA ≤ 0.3 cm. We calculated the uncertainty of dose-volume-histogram estimates (mean and D0.1 cm³) and voxel-wise uncertainties using standard deviation (SD). We also tested the impact of using fewer registrations.

Results

DIR resulted in plausible mappings for both patient cohorts’ OARs, ranging between 78.6 % and 88.2 %, varying between patients and OARs. Mean dose uncertainties ranged between 0 Gy and 0.43 Gy, while larger differences were observed for D0.1 cm3, between 0 Gy and 0.78 Gy. As expected, large voxel-wise uncertainties were in regions of steep dose gradients. Performance between registration sets was similar.

Conclusion

We developed a method to estimate dose mapping uncertainties with integrated quality control for reirradiation. Differences between patients were observed, justifying the need for individualised DIR assessment. Few registrations were a pragmatic approach.

背景和目的形变图像配准（DIR）允许在再照射计划扫描中评估先前治疗过程的辐射剂量。然而，DIR可能在剂量图中引入不确定性。估计个别患者的这些不确定性仍然是一个关键的挑战。我们开发了一种个性化的方法，使用市售的治疗计划系统来估计剂量图中的不确定性。材料和方法对54例接受再照射的患者（27例头颈部、H&；N和27例肺部），我们对每位患者进行了16次DIRs。我们使用30至34个危险器官（OARs）的绘制轮廓线与相应结构之间的平均一致距离（mDTA）对每个DIR进行几何评估。然后，我们估计了DIR导致合理配准的结构的剂量映射不确定性，定义为mDTA≤0.3 cm。我们计算了剂量-体积-直方图估计的不确定性（平均值和D0.1 cm3）和使用标准差（SD）的体素不确定性。我们还测试了使用更少注册的影响。结果dir对两组患者的桨位进行了合理的映射，范围在78.6%到88.2%之间，在患者和桨位之间有所不同。平均剂量不确定性介于0 Gy和0.43 Gy之间，而D0.1 cm3的差异更大，介于0 Gy和0.78 Gy之间。正如预期的那样，在剂量梯度较大的区域存在较大的体素不确定性。注册集之间的性能是相似的。结论建立了一种综合质量控制的剂量图不确定度估算方法。观察到患者之间的差异，证明了个体化DIR评估的必要性。很少注册是一种务实的方法。

{"title":"Individualised dose mapping uncertainty estimation in the reirradiation setting","authors":"Chelmis Muthoni Thiong’o , Marcel van Herk , Kathryn Banfill , Clara Chan , Catherine Harris , Matthew Lowe , Tom Marchant , Iskandar Mohamed , Golnoosh Motamedi-Ghahfarokhi , David Thomson , Ane Appelt , Eliana Vasquez Osorio","doi":"10.1016/j.phro.2025.100881","DOIUrl":"10.1016/j.phro.2025.100881","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Deformable image registration (DIR) allows assessing radiation doses of previous treatment courses in reirradiation planning scans. However, DIR can introduce uncertainties in dose mapping. Estimating these uncertainties for individual patients remains a key challenge. We developed an individualised approach to estimate uncertainties in dose mapping using a commercially available treatment planning system.</div></div><div><h3>Materials and methods</h3><div>For 54 patients who underwent reirradiation (27 head and neck, H&N, and 27 lung cases), we performed 16 DIRs per patient. We assessed each DIR geometrically using the mean distance to agreement (mDTA) between mapped contours and the corresponding structures of 30 to 34 organs at risk (OARs). We then estimated dose mapping uncertainties for structures where DIR resulted in plausible registrations, defined as mDTA ≤ 0.3 cm. We calculated the uncertainty of dose-volume-histogram estimates (mean and D0.1 cm<sup>3</sup>) and voxel-wise uncertainties using standard deviation (SD). We also tested the impact of using fewer registrations.</div></div><div><h3>Results</h3><div>DIR resulted in plausible mappings for both patient cohorts’ OARs, ranging between 78.6 % and 88.2 %, varying between patients and OARs. Mean dose uncertainties ranged between 0 Gy and 0.43 Gy, while larger differences were observed for D0.1 cm3, between 0 Gy and 0.78 Gy. As expected, large voxel-wise uncertainties were in regions of steep dose gradients. Performance between registration sets was similar.</div></div><div><h3>Conclusion</h3><div>We developed a method to estimate dose mapping uncertainties with integrated quality control for reirradiation. Differences between patients were observed, justifying the need for individualised DIR assessment. Few registrations were a pragmatic approach.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100881"},"PeriodicalIF":3.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681033","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

Triggered plan adaptation using multi-image optimization for improved robustness in head-and-neck cancer proton therapy 基于多图像优化的触发计划自适应提高头颈癌质子治疗的鲁棒性

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100871

Nadine Vatterodt , Brian Winey , Stine S. Korreman

Background and purpose

Anatomical variations in head-and-neck (HNC) proton therapy may degrade target coverage and organ-at-risk (OAR) sparing. This study introduces a triggered robust adaptation strategy utilizing multi-image optimization to progressively enhance plan robustness guided by observed dose deviations for targets and OARs.

Material and methods

Five oropharyngeal cancer patients treated with proton therapy were retrospectively analyzed. Synthetic computed tomography (CT) scans were generated from daily cone-beam CTs for dose recalculation. Four strategies were compared: no adaptation (NA), triggered adaptation without anatomical robustness (TA), and triggered robust adaptation using single (TRA-S) or multiple (TRA-M) triggered fraction images. Adaptation was triggered by exceeded thresholds in dose-volume metric deviations. Treatment strategies were evaluated by comparing target coverage, OAR dose, integral dose and number of threshold violations.

Results

TRA-S and TRA-M consistently improved target coverage up to +0.76 Gy in median D_98% vs. NA, with fewer threshold violations (5 and 4) compared to NA and TA (both 8). Larger unfavorable dose deviations were reduced, with OAR doses generally comparable to NA. TA maintained OAR doses closer to the planned values, while not improving target coverage in all cases. Integral dose increased with TRA strategies up to 3.7 Gy·L compared to NA. Differences between TRA-S and TRA-M were generally small.

Conclusion

Triggered robust adaptation balanced target coverage and OAR sparing, while requiring fewer adaptations compared to triggered adaptation without anatomical robustness. It offers a potential pathway for implementing anatomical robust optimization in HNC proton therapy without relying on predicted images or additional CT scans.

背景与目的头颈部（HNC）质子治疗的解剖差异可能降低靶覆盖和危险器官（OAR）的保留。本研究引入了一种触发型鲁棒自适应策略，利用多图像优化，在观测到的剂量偏差指导下逐步增强目标和桨的计划鲁棒性。材料与方法对5例经质子治疗的口咽癌患者进行回顾性分析。合成计算机断层扫描（CT）扫描由每日锥形束CT生成，用于剂量重新计算。比较了四种策略：无适应性（NA）、触发适应性（TA）和触发适应性（单个（TRA-S）或多个（TRA-M）触发分数图像）。适应是在剂量-体积度量偏差超过阈值时触发的。通过比较靶覆盖率、OAR剂量、积分剂量和阈值违规次数来评估治疗策略。结果与NA相比，tra - s和TRA-M在中位D98%中持续提高目标覆盖率，最高可达+0.76 Gy，与NA和TA（均为8）相比，阈值违规（5和4）较少。较大的不利剂量偏差减少，OAR剂量通常与NA相当。TA维持桨叶剂量更接近计划值，但没有在所有情况下提高目标覆盖率。与NA相比，TRA策略的整体剂量增加至3.7 Gy·L。TRA-S和TRA-M之间的差异一般较小。与没有解剖稳健性的触发适应相比，触发适应需要更少的适应，同时平衡了目标覆盖和桨叶保护。它为HNC质子治疗中实现解剖学稳健优化提供了潜在途径，而无需依赖于预测图像或额外的CT扫描。

{"title":"Triggered plan adaptation using multi-image optimization for improved robustness in head-and-neck cancer proton therapy","authors":"Nadine Vatterodt , Brian Winey , Stine S. Korreman","doi":"10.1016/j.phro.2025.100871","DOIUrl":"10.1016/j.phro.2025.100871","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Anatomical variations in head-and-neck (HNC) proton therapy may degrade target coverage and organ-at-risk (OAR) sparing. This study introduces a triggered robust adaptation strategy utilizing multi-image optimization to progressively enhance plan robustness guided by observed dose deviations for targets and OARs.</div></div><div><h3>Material and methods</h3><div>Five oropharyngeal cancer patients treated with proton therapy were retrospectively analyzed. Synthetic computed tomography (CT) scans were generated from daily cone-beam CTs for dose recalculation. Four strategies were compared: no adaptation (<em>NA</em>), triggered adaptation without anatomical robustness (<em>TA</em>), and triggered robust adaptation using single (<em>TRA-S</em>) or multiple (<em>TRA-M</em>) triggered fraction images. Adaptation was triggered by exceeded thresholds in dose-volume metric deviations. Treatment strategies were evaluated by comparing target coverage, OAR dose, integral dose and number of threshold violations.</div></div><div><h3>Results</h3><div><em>TRA-S</em> and <em>TRA-M</em> consistently improved target coverage up to +0.76 Gy in median D<sub>98%</sub> vs. <em>NA</em>, with fewer threshold violations (5 and 4) compared to <em>NA</em> and <em>TA</em> (both 8). Larger unfavorable dose deviations were reduced, with OAR doses generally comparable to NA. <em>TA</em> maintained OAR doses closer to the planned values, while not improving target coverage in all cases. Integral dose increased with <em>TRA</em> strategies up to 3.7 Gy·L compared to <em>NA</em>. Differences between <em>TRA-S</em> and <em>TRA-M</em> were generally small.</div></div><div><h3>Conclusion</h3><div>Triggered robust adaptation balanced target coverage and OAR sparing, while requiring fewer adaptations compared to triggered adaptation without anatomical robustness. It offers a potential pathway for implementing anatomical robust optimization in HNC proton therapy without relying on predicted images or additional CT scans.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100871"},"PeriodicalIF":3.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681034","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

Integrating spot-scanning proton arc therapy with functional avoidance strategies to reduce pulmonary toxicity 将点扫描质子弧治疗与功能回避策略相结合，降低肺毒性

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100876

Yingxuan Chen , Peilin Liu , Xiaoda Cong , Edward Castillo , Richard Castillo , Inga Grills , Craig Stevens , Xiangkun Xu , Xiaoqiang Li , Yevgeniy Vinogradskiy , Xuanfeng Ding

Background and purpose

Functional avoidance radiotherapy has emerged as a promising technique using functional imaging to minimize pulmonary toxicity by reducing doses to functional lung. This study aims to investigate the potential dose-volume advantages of a novel spot-scanning proton arc (SPArc) therapy for functional avoidance radiotherapy with four-dimensional computed tomography (4DCT)-based ventilation imaging.

Material and methods

Twenty-five patients from a prospective functional avoidance clinical trial treated with intensity-modulated photon radiotherapy were included. Robustly optimized intensity modulated proton therapy (IMPT) and SPArc plans were generated in RayStation. Functional lung contour was derived from the 4DCT-based ventilation imaging and utilized as an optimization structure in photon as well as IMPT and SPArc functional planning. The dose distributions were compared, and normal tissue complication probability (NTCP) models were applied to estimate the probability of pulmonary toxicity.

Results

Using clinical photon plans as the baseline for comparison, both proton plans achieved equivalent target coverage and reduced dose to organs at risk. Compared with photon plans, the median absolute reduction of fV_20Gy (the volume of functional lung receiving ≥ 20 Gy) was 3.7 percentage points (pp) with IMPT and 13.0 pp with SPArc. Using fV_20Gy for NTCP estimation, the median reduction of probability of grade ≥ 2 pneumonitis was 5.0 pp with IMPT and was 14.9 pp with SPArc.

Conclusions

Our study highlighted the potential of SPArc to spare dose to functional lung. NTCP results further indicated that the risk of pulmonary complications can be reduced with SPArc compared to photon or IMPT for functional avoidance radiotherapy.

背景和目的功能回避放射治疗已成为一种很有前途的技术，利用功能成像通过减少对功能肺的剂量来减少肺毒性。本研究旨在探讨基于四维计算机断层扫描（4DCT）通气成像的新型点扫描质子弧（SPArc）治疗功能回避放疗的潜在剂量-体积优势。材料与方法采用调强光子放射治疗的前瞻性功能回避临床试验患者25例。在RayStation中生成稳健优化的强度调制质子治疗（IMPT）和SPArc计划。基于4dct的通气成像得到肺功能轮廓，并将其作为光子、IMPT和SPArc功能规划的优化结构。比较剂量分布，应用正常组织并发症概率（NTCP）模型估计肺毒性的概率。结果以临床光子治疗方案为对照，两种质子治疗方案均达到了相同的靶覆盖范围，并减少了危及器官的剂量。与光子计划相比，IMPT组fV20Gy（接受≥20Gy的功能肺体积）的中位数绝对减少3.7个百分点（pp）， SPArc组为13.0个百分点。使用fV20Gy进行NTCP估计，IMPT组≥2级肺炎的概率降低中位数为5.0 pp， SPArc组为14.9 pp。结论sour研究强调了SPArc对功能性肺的备用剂量潜力。NTCP结果进一步表明，与光子或IMPT相比，SPArc可降低肺并发症的风险。

{"title":"Integrating spot-scanning proton arc therapy with functional avoidance strategies to reduce pulmonary toxicity","authors":"Yingxuan Chen , Peilin Liu , Xiaoda Cong , Edward Castillo , Richard Castillo , Inga Grills , Craig Stevens , Xiangkun Xu , Xiaoqiang Li , Yevgeniy Vinogradskiy , Xuanfeng Ding","doi":"10.1016/j.phro.2025.100876","DOIUrl":"10.1016/j.phro.2025.100876","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Functional avoidance radiotherapy has emerged as a promising technique using functional imaging to minimize pulmonary toxicity by reducing doses to functional lung. This study aims to investigate the potential dose-volume advantages of a novel spot-scanning proton arc (SPArc) therapy for functional avoidance radiotherapy with four-dimensional computed tomography (4DCT)-based ventilation imaging.</div></div><div><h3>Material and methods</h3><div>Twenty-five patients from a prospective functional avoidance clinical trial treated with intensity-modulated photon radiotherapy were included. Robustly optimized intensity modulated proton therapy (IMPT) and SPArc plans were generated in RayStation. Functional lung contour was derived from the 4DCT-based ventilation imaging and utilized as an optimization structure in photon as well as IMPT and SPArc functional planning. The dose distributions were compared, and normal tissue complication probability (NTCP) models were applied to estimate the probability of pulmonary toxicity.</div></div><div><h3>Results</h3><div>Using clinical photon plans as the baseline for comparison, both proton plans achieved equivalent target coverage and reduced dose to organs at risk. Compared with photon plans, the median absolute reduction of fV<sub>20Gy</sub> (the volume of functional lung receiving ≥ 20 Gy) was 3.7 percentage points (pp) with IMPT and 13.0 pp with SPArc. Using fV<sub>20Gy</sub> for NTCP estimation, the median reduction of probability of grade ≥ 2 pneumonitis was 5.0 pp with IMPT and was 14.9 pp with SPArc.</div></div><div><h3>Conclusions</h3><div>Our study highlighted the potential of SPArc to spare dose to functional lung. NTCP results further indicated that the risk of pulmonary complications can be reduced with SPArc compared to photon or IMPT for functional avoidance radiotherapy.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100876"},"PeriodicalIF":3.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681096","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

Statistical process control for performance monitoring and continuous quality assurance of deep learning segmentations in radiotherapy 放疗中深度学习分割性能监测和持续质量保证的统计过程控制

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100873

Niels van Acht , Dave van Gruijthuijsen , Johanna Bluemink , Els Hagelaar , Coen Hurkmans

Background and purpose

After clinical implementation of deep learning segmentation (DLS) models it is highly recommended to perform routine quality assurance (QA). Through forthcoming regulations of the EU AI Act state that the output of any DLS model needs to be logged, enabling continuous QA (CQA) to monitor DLS performance and introduce alarms. Therefore, the goal was to implement a CQA framework for DLS in radiotherapy.

Materials and methods

The direct output of the DLS models and the clinically approved delineations (CS) were automatically exported, after which geometric metrics were calculated. For each combination between a region of interest (ROI) and metric, a target, lower and upper control limit were determined, based on statistical process control (SPC). Adapted versions of the first three Nelson rules were used for outlier identification and detection of trend shifts and drifts.

Results

In the first six months, 545 DLS and corresponding CS RT structure files were logged containing 3093 ROIs. From these ROIs, 3.0 % was automatically reported as outlier. Data from 5 patients, which anatomy was deemed interesting, was saved for potential model re-training. Four trend shifts identified a performance drop for the humerus due to unexpected changes. Twelve other trend shifts and one trend drift were detected, causing only temporary deviations.

Conclusions

A CQA framework for DLS was successfully implemented using SPC and adapted Nelson rules to automatically report outliers and trend shifts, which led to automatic detection of such deviations.

背景与目的在临床应用深度学习分割（DLS）模型后，强烈建议进行常规质量保证（QA）。根据即将出台的欧盟人工智能法案规定，任何DLS模型的输出都需要记录，从而实现持续的QA （CQA）来监控DLS的性能并引入警报。因此，我们的目标是为放疗中的DLS实施一个CQA框架。材料和方法直接输出DLS模型和临床批准的划定（CS），然后计算几何指标。对于感兴趣区域（ROI）和度量之间的每个组合，基于统计过程控制（SPC）确定目标，下限和上限。前三个纳尔逊规则的改编版本被用于异常值识别和趋势转移和漂移的检测。结果前6个月共记录DLS及相应的CS RT结构文件545份，roi 3093份。从这些roi中，3.0%被自动报告为异常值。5例患者的数据被认为是有趣的解剖结构，用于潜在的模型再训练。由于意想不到的变化，四个趋势变化确定了肱骨的性能下降。另外还发现了12次趋势转移和1次趋势漂移，但只造成了暂时的偏差。结论采用SPC和Nelson规则，成功实现了DLS的CQA框架，自动报告异常值和趋势变化，实现了偏差的自动检测。

{"title":"Statistical process control for performance monitoring and continuous quality assurance of deep learning segmentations in radiotherapy","authors":"Niels van Acht , Dave van Gruijthuijsen , Johanna Bluemink , Els Hagelaar , Coen Hurkmans","doi":"10.1016/j.phro.2025.100873","DOIUrl":"10.1016/j.phro.2025.100873","url":null,"abstract":"<div><h3>Background and purpose</h3><div>After clinical implementation of deep learning segmentation (DLS) models it is highly recommended to perform routine quality assurance (QA). Through forthcoming regulations of the EU AI Act state that the output of any DLS model needs to be logged, enabling continuous QA (CQA) to monitor DLS performance and introduce alarms. Therefore, the goal was to implement a CQA framework for DLS in radiotherapy.</div></div><div><h3>Materials and methods</h3><div>The direct output of the DLS models and the clinically approved delineations (CS) were automatically exported, after which geometric metrics were calculated. For each combination between a region of interest (ROI) and metric, a target, lower and upper control limit were determined, based on statistical process control (SPC). Adapted versions of the first three Nelson rules were used for outlier identification and detection of trend shifts and drifts.</div></div><div><h3>Results</h3><div>In the first six months, 545 DLS and corresponding CS RT structure files were logged containing 3093 ROIs. From these ROIs, 3.0 % was automatically reported as outlier. Data from 5 patients, which anatomy was deemed interesting, was saved for potential model re-training. Four trend shifts identified a performance drop for the humerus due to unexpected changes. Twelve other trend shifts and one trend drift were detected, causing only temporary deviations.</div></div><div><h3>Conclusions</h3><div>A CQA framework for DLS was successfully implemented using SPC and adapted Nelson rules to automatically report outliers and trend shifts, which led to automatic detection of such deviations.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100873"},"PeriodicalIF":3.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614362","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

Quantitative evaluation of apparent diffusion coefficient in a large multi-unit institution 大型多单位机构中表观扩散系数的定量评价

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100856

Joshua P. Yung , Yao Ding , Ken-Pin Hwang , Carlos E. Cardenas , H.Asher Ai , Lucas McCullum , Natalie A. West , Clifton D. Fuller , R. Jason Stafford

Background and purpose

Diffusion weighted imaging (DWI) and their calculated apparent diffusion coefficient (ADC) values in magnetic resonance imaging (MRI) has grown with applications across multiple anatomical sites and settings across diagnostic and oncologic therapy settings, necessitating characterizing its quantitative performance across multiple scanners. Therefore, the purpose of this study was to determine the quantitative accuracy of DWI and their calculated ADC values across a fleet of MRI systems using a NIST-traceable diffusion phantom.

Materials and methods

Three NIST/QIBA DWI phantoms were imaged with protocols provided with the phantom on a multi-vendor fleet of 23 clinical MRI scanners. User-directed regions-of-interest on each vial provided ADC measurements among a wide range of NIST-traceable ADC values. Across all the MRI systems and data, the coefficient-of-variation was calculated, and Bland-Altman analysis was performed. The measurements between phantoms were analyzed to assess their agreement to determine if multiple phantoms can be used for quality assurance across a large institution.

Results

Lower ADC values and the sagittal orientation exhibited the largest error range and coefficient-of-variation (CoV) and was directly related to SNR. From a one-way analysis of the variance (ANOVA), the mean and standard deviation of the percent errors from each phantom were not significantly different from one another. No strong differences in Bland-Altman plots were seen between 1.5T and 3T scanners, however confidence intervals were different among vendors. The ADC values among the three phantoms were not significantly different from one another.

Conclusions

A comprehensive analysis of institution-wide MRI scanners was conducted, motivating further work to utilize these results to implement a comprehensive quality assurance program and advanced scheduling system to better match similarly performing MRI scanners.

背景和目的磁共振成像（MRI）中的扩散加权成像（DWI）及其计算的表观扩散系数（ADC）值随着其在多个解剖部位和诊断和肿瘤治疗环境中的应用而增长，有必要在多个扫描仪中表征其定量性能。因此，本研究的目的是确定DWI的定量准确性及其计算的ADC值在一系列MRI系统中使用nist可追踪的扩散幻影。材料和方法三个NIST/QIBA DWI幻像在多供应商的23台临床MRI扫描仪上进行成像。每个小瓶上的用户定向兴趣区域在广泛的nist可追溯ADC值中提供ADC测量。在所有MRI系统和数据中，计算变异系数，并进行Bland-Altman分析。分析幻影之间的测量，以评估它们的一致性，以确定多个幻影是否可以用于大型机构的质量保证。结果低ADC值和矢状方向误差范围和变异系数最大，与信噪比直接相关。从方差的单向分析（ANOVA）中，每个幻影的百分比误差的平均值和标准偏差彼此之间没有显着差异。在1.5T和3T扫描仪之间，Bland-Altman图没有明显差异，但不同供应商之间的置信区间不同。三种幻像之间的ADC值无显著差异。结论对全院范围的MRI扫描仪进行了全面的分析，激励进一步的工作，利用这些结果来实施全面的质量保证计划和先进的调度系统，以更好地匹配性能相似的MRI扫描仪。

{"title":"Quantitative evaluation of apparent diffusion coefficient in a large multi-unit institution","authors":"Joshua P. Yung , Yao Ding , Ken-Pin Hwang , Carlos E. Cardenas , H.Asher Ai , Lucas McCullum , Natalie A. West , Clifton D. Fuller , R. Jason Stafford","doi":"10.1016/j.phro.2025.100856","DOIUrl":"10.1016/j.phro.2025.100856","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Diffusion weighted imaging (DWI) and their calculated apparent diffusion coefficient (ADC) values in magnetic resonance imaging (MRI) has grown with applications across multiple anatomical sites and settings across diagnostic and oncologic therapy settings, necessitating characterizing its quantitative performance across multiple scanners. Therefore, the purpose of this study was to determine the quantitative accuracy of DWI and their calculated ADC values across a fleet of MRI systems using a NIST-traceable diffusion phantom.</div></div><div><h3>Materials and methods</h3><div>Three NIST/QIBA DWI phantoms were imaged with protocols provided with the phantom on a multi-vendor fleet of 23 clinical MRI scanners. User-directed regions-of-interest on each vial provided ADC measurements among a wide range of NIST-traceable ADC values. Across all the MRI systems and data, the coefficient-of-variation was calculated, and Bland-Altman analysis was performed. The measurements between phantoms were analyzed to assess their agreement to determine if multiple phantoms can be used for quality assurance across a large institution.</div></div><div><h3>Results</h3><div>Lower ADC values and the sagittal orientation exhibited the largest error range and coefficient-of-variation (CoV) and was directly related to SNR. From a one-way analysis of the variance (ANOVA), the mean and standard deviation of the percent errors from each phantom were not significantly different from one another. No strong differences in Bland-Altman plots were seen between 1.5T and 3T scanners, however confidence intervals were different among vendors. The ADC values among the three phantoms were not significantly different from one another.</div></div><div><h3>Conclusions</h3><div>A comprehensive analysis of institution-wide MRI scanners was conducted, motivating further work to utilize these results to implement a comprehensive quality assurance program and advanced scheduling system to better match similarly performing MRI scanners.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100856"},"PeriodicalIF":3.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145466705","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

Comparison of protons and very high-energy electrons transmission pencil-beam-scanning for FLASH radiotherapy 质子和高能电子透射铅笔束扫描在FLASH放射治疗中的比较

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100860

Flavia Gesualdi , Louis Ermeneux , Pierre Lansonneur , Mateusz Sitarz , Pierre Loap , Gilles Créhange , Anthony Magliari , Ludovic De Marzi

Background and purpose

Very High-Energy Electron (VHEE) radiotherapy stands as a promising alternative to proton therapy in view of the FLASH effect, which allows for differential sparing of healthy tissues under ultra-high dose rate irradiation. This study compared the quality of transmission Pencil-Beam-Scanning proton and VHEE treatment plans, with emphasis on dose rate quantification relevant to the assessment of the FLASH effect.

Materials and methods

Proton (250 MeV) and VHEE (200 MeV and 150 MeV) treatment plans were designed for four patient cases. Plans were optimized using an in-house developed spot weight and position optimization algorithm. Objectives were set through scorecards based on RTOG protocols. Dose rate estimations were based on beam parameters of the ProBeam system for protons and of a realistic VHEE system. For each structure, a new, model-free FLASH index was calculated.

Results

VHEE treatment plans achieved a quality comparable to that of protons. While the conformity and homogeneity were similar, FLASH indices tended to be higher for protons due to higher dose rates covering more healthy tissues. A pulse repetition frequency of 500 Hz was found necessary to attain FLASH-compatible dose rates (≥40 Gy/s).

Conclusions

The importance of treatment parameters (such as pulse repetition frequency) for VHEEs to reach ultra-high dose rates was assessed. With their high plan quality, VHEEs could constitute a viable alternative to proton transmission plans and a promising modality for FLASH therapy. The proposed FLASH index offers a robust tool to compare the FLASH potential across treatment modalities.

背景和目的高能电子（VHEE）放射治疗是质子治疗的一种很有前途的替代方案，因为它具有FLASH效应，可以在超高剂量率照射下对健康组织进行不同程度的保护。本研究比较了透射铅笔束扫描质子和VHEE治疗方案的质量，重点是与评估FLASH效应相关的剂量率量化。材料与方法对4例患者设计质子治疗方案（250 MeV）和VHEE治疗方案（200 MeV和150 MeV）。平面图使用内部开发的点重量和位置优化算法进行优化。通过基于RTOG协议的记分卡设定目标。剂量率估计是基于质子ProBeam系统和实际VHEE系统的光束参数。对于每个结构，计算一个新的、无模型的FLASH指数。结果vhee治疗方案达到了与质子治疗相当的质量。虽然一致性和均匀性相似，但由于更高的剂量率覆盖更多的健康组织，质子的FLASH指数往往更高。需要500 Hz的脉冲重复频率才能达到flash兼容的剂量率（≥40 Gy/s）。结论评价了治疗参数（如脉冲重复频率）对VHEEs达到超高剂量率的重要性。由于其高质量的计划，VHEEs可以成为质子传输计划的可行替代方案，也是FLASH治疗的一种有前途的方式。拟议的FLASH指数提供了一个强大的工具来比较不同治疗方式的FLASH潜力。

{"title":"Comparison of protons and very high-energy electrons transmission pencil-beam-scanning for FLASH radiotherapy","authors":"Flavia Gesualdi , Louis Ermeneux , Pierre Lansonneur , Mateusz Sitarz , Pierre Loap , Gilles Créhange , Anthony Magliari , Ludovic De Marzi","doi":"10.1016/j.phro.2025.100860","DOIUrl":"10.1016/j.phro.2025.100860","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Very High-Energy Electron (VHEE) radiotherapy stands as a promising alternative to proton therapy in view of the FLASH effect, which allows for differential sparing of healthy tissues under ultra-high dose rate irradiation. This study compared the quality of transmission Pencil-Beam-Scanning proton and VHEE treatment plans, with emphasis on dose rate quantification relevant to the assessment of the FLASH effect.</div></div><div><h3>Materials and methods</h3><div>Proton (250 MeV) and VHEE (200 MeV and 150 MeV) treatment plans were designed for four patient cases. Plans were optimized using an in-house developed spot weight and position optimization algorithm. Objectives were set through scorecards based on RTOG protocols. Dose rate estimations were based on beam parameters of the ProBeam system for protons and of a realistic VHEE system. For each structure, a new, model-free FLASH index was calculated.</div></div><div><h3>Results</h3><div>VHEE treatment plans achieved a quality comparable to that of protons. While the conformity and homogeneity were similar, FLASH indices tended to be higher for protons due to higher dose rates covering more healthy tissues. A pulse repetition frequency of 500 Hz was found necessary to attain FLASH-compatible dose rates (≥40 Gy/s).</div></div><div><h3>Conclusions</h3><div>The importance of treatment parameters (such as pulse repetition frequency) for VHEEs to reach ultra-high dose rates was assessed. With their high plan quality, VHEEs could constitute a viable alternative to proton transmission plans and a promising modality for FLASH therapy. The proposed FLASH index offers a robust tool to compare the FLASH potential across treatment modalities.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100860"},"PeriodicalIF":3.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145466707","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

Diffusion-weighted imaging-derived parameters as quantitative imaging biomarkers in magnetic resonance-guided radiotherapy: a systematic review 磁共振引导放射治疗中扩散加权成像衍生参数作为定量成像生物标志物：系统综述

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100843

Jing Yuan , Darren M.C. Poon , Oi Lei Wong , Cindy Xue , Amy Tien Yee Chang , Bin Yang

Background and purpose

Magnetic Resonance Linear Accelerators (MR-LINACs) have transformed radiotherapy by integrating high-resolution magnetic resonance imaging (MRI) with precise radiation delivery. Diffusion-Weighted Imaging (DWI)-derived parameters are promising non-invasive quantitative imaging biomarkers (QIBs) for MR-guided radiotherapy (MRgRT), primarily through apparent diffusion coefficient (ADC) and intravoxel incoherent motion (IVIM) models; however, their clinical utility and validation on MR-LINAC systems remain underexplored. This systematic review evaluates DWI’s technical development, validation, and clinical role in MRgRT using MR-LINACs.

Material and methods

Following PRISMA guidelines, PubMed/MEDLINE, Web of Science, and Scopus (2014–2024) were searched for English-language studies on DWI in MRgRT with MR-LINACs (0.35 T or 1.5 T). Eligible studies included technical and clinical research with phantoms, volunteers, or patients. Data on study characteristics, DWI protocols, validation metrics, and clinical endpoints were extracted and qualitatively synthesized; heterogeneity precluded meta-analysis.

Results

Thirty-four studies (11 at 0.35 T, 23 at 1.5 T) were included (29 prospective, 5 retrospective), with 28 involving patients (N = 484) across cancers. DWI, primarily via single-shot EPI (median time ∼4–5 min, b-values 0–2000 s/mm²), demonstrates robust technical feasibility (27 studies) and emerging clinical validity (8 studies, ∼212 patients). Most validation remains single-center; multi-center and cost-effectiveness data are lacking, and only one study systematically evaluated imaging-genomic correlation with IVIM.

Discussion

DWI on MR-LINACs is technically available, feasible, and clinically promising for MRgRT. However, its QIB potential is limited by inconsistent protocols, hardware constraints, and preliminary clinical validation. Standardized protocols, hardware upgrades, and rigorous multi-center trials are essential to establish DWI-derived parameters as reliable QIBs for MRgRT.

背景与目的磁共振线性加速器（MR-LINACs）通过将高分辨率磁共振成像（MRI）与精确的辐射传输相结合，已经改变了放射治疗。弥散加权成像（DWI）衍生的参数主要通过表观扩散系数（ADC）和体素内非相干运动（IVIM）模型，是mri引导放射治疗（MRgRT）有前途的非侵入性定量成像生物标志物（qib）；然而，它们在MR-LINAC系统上的临床应用和验证仍未得到充分探索。本系统综述评估了DWI在MRgRT中使用MR-LINACs的技术发展、验证和临床作用。材料和方法按照PRISMA指南，检索PubMed/MEDLINE、Web of Science和Scopus(2014-2024)，检索MR-LINACs的MRgRT中DWI的英文研究（0.35 T或1.5 T）。符合条件的研究包括与幽灵、志愿者或患者进行的技术和临床研究。提取研究特征、DWI方案、验证指标和临床终点的数据并进行定性合成；异质性排除了meta分析。结果纳入34项研究（11项为0.35 T， 23项为1.5 T）（29项前瞻性研究，5项回顾性研究），其中28项涉及癌症患者（N = 484）。DWI主要通过单次EPI（中位时间~ 4-5 min， b值0-2000 s/mm2），显示出强大的技术可行性（27项研究）和新兴的临床有效性（8项研究，约212例患者）。大多数验证仍然是单中心的；缺乏多中心和成本-效果的数据，只有一项研究系统地评估了成像-基因组与IVIM的相关性。dwi对MR-LINACs的治疗在技术上是可行的，并且在MRgRT中具有临床应用前景。然而，它的QIB潜力受到协议不一致、硬件限制和初步临床验证的限制。标准化协议、硬件升级和严格的多中心试验对于建立dwi衍生参数作为MRgRT可靠的qib至关重要。

{"title":"Diffusion-weighted imaging-derived parameters as quantitative imaging biomarkers in magnetic resonance-guided radiotherapy: a systematic review","authors":"Jing Yuan , Darren M.C. Poon , Oi Lei Wong , Cindy Xue , Amy Tien Yee Chang , Bin Yang","doi":"10.1016/j.phro.2025.100843","DOIUrl":"10.1016/j.phro.2025.100843","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Magnetic Resonance Linear Accelerators (MR-LINACs) have transformed radiotherapy by integrating high-resolution magnetic resonance imaging (MRI) with precise radiation delivery. Diffusion-Weighted Imaging (DWI)-derived parameters are promising non-invasive quantitative imaging biomarkers (QIBs) for MR-guided radiotherapy (MRgRT), primarily through apparent diffusion coefficient (ADC) and intravoxel incoherent motion (IVIM) models; however, their clinical utility and validation on MR-LINAC systems remain underexplored. This systematic review evaluates DWI’s technical development, validation, and clinical role in MRgRT using MR-LINACs.</div></div><div><h3>Material and methods</h3><div>Following PRISMA guidelines, PubMed/MEDLINE, Web of Science, and Scopus (2014–2024) were searched for English-language studies on DWI in MRgRT with MR-LINACs (0.35 T or 1.5 T). Eligible studies included technical and clinical research with phantoms, volunteers, or patients. Data on study characteristics, DWI protocols, validation metrics, and clinical endpoints were extracted and qualitatively synthesized; heterogeneity precluded <em>meta</em>-analysis.</div></div><div><h3>Results</h3><div>Thirty-four studies (11 at 0.35 T, 23 at 1.5 T) were included (29 prospective, 5 retrospective), with 28 involving patients (N = 484) across cancers. DWI, primarily via single-shot EPI (median time ∼4–5 min, b-values 0–2000 s/mm<sup>2</sup>), demonstrates robust technical feasibility (27 studies) and emerging clinical validity (8 studies, ∼212 patients). Most validation remains single-center; multi-center and cost-effectiveness data are lacking, and only one study systematically evaluated imaging-genomic correlation with IVIM.</div></div><div><h3>Discussion</h3><div>DWI on MR-LINACs is technically available, feasible, and clinically promising for MRgRT. However, its QIB potential is limited by inconsistent protocols, hardware constraints, and preliminary clinical validation. Standardized protocols, hardware upgrades, and rigorous multi-center trials are essential to establish DWI-derived parameters as reliable QIBs for MRgRT.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100843"},"PeriodicalIF":3.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268550","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