Physics and Imaging in Radiation Oncology最新文献_第4页

Establishing prospective performance monitoring for real-world implementation of deep learning-based auto-segmentation in prostate cancer radiotherapy 为前列腺癌放疗中基于深度学习的自动分割的实际实施建立前瞻性性能监测

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100886

Libing Zhu , Yi Rong , Nathan Y. Yu , Jason M. Holmes , Carlos E. Vargas , Sarah E. James , Lu Shang , Jean-Claude M. Rwigema , Quan Chen

Background and purpose

Deep-learning auto-segmentation (DLAS) performance in radiotherapy may change over time due to data shift/drift or practice changes, yet guidance for quality assurance is lacking. This study developed a practical framework for prospective performance monitoring using retrospective data.

Methods

A total of 464 prostate cases over 20 months were retrospectively collected. Two commercial DLAS models were clinically used: model A (2D U-Net, January 2022–January 2023) and model B (3D U-Net, February–August 2023). The agreement between DLAS and clinical contours was assessed using Dice Similarity Coefficient (DSC), 95th percentile Hausdorff Distance (HD95), and Surface DSC with a 2 mm tolerance (SDSC). Statistical process control charts were created to monitor performance drift and model switching. The first 150 cases were used to define organ-specific control limits with two and three standard deviations of monthly mean values,

σ_{\bar{x}}

.

Results

2

σ_{\bar{x}}

and 3

σ_{\bar{x}}

-based control limits were established for the monthly average charts, ranging from DSC 0.82–0.97, HD95 1.4–10.5 mm, and SDSC 0.45–0.91 across organs. Model A showed stable performance, with 9–13 months per organ remaining within the 3

σ_{\bar{x}}

thresholds. In contrast, model B demonstrated a marked performance shift (p < 0.001), with all five organs exceeding both thresholds across all 7 months. The 2

σ_{\bar{x}}

thresholds were more sensitive in detecting mild deviations for model A, while both limits effectively identified the substantial drift of model B.

Conclusion

The monitoring system effectively detected out-of-distribution outliers and clinical practice changes, providing a reliable framework for early detection of monthly performance degradation.

背景和目的放疗中的深度学习自动分割（DLAS）性能可能会随着时间的推移而变化，因为数据移位/漂移或实践变化，但缺乏质量保证的指导。本研究开发了一个使用回顾性数据进行前瞻性绩效监测的实用框架。方法回顾性收集近20个月464例前列腺癌患者的资料。临床使用两种商用DLAS模型：A模型（2D U-Net， 2022年1月- 2023年1月）和B模型（3D U-Net， 2023年2月- 8月）。采用Dice Similarity Coefficient （DSC）、第95百分位Hausdorff Distance （HD95）和Surface DSC与2mm容差（SDSC）来评估DLAS与临床轮廓的一致性。创建了统计过程控制图来监视性能漂移和模型切换。用前150例的月平均值σx¯的2和3个标准差来定义器官特异性控制极限。结果建立了2σx¯和3σx¯的月平均图控制限，各器官间DSC为0.82 ~ 0.97，HD95为1.4 ~ 10.5 mm， SDSC为0.45 ~ 0.91。模型A表现出稳定的性能，每个器官9-13个月保持在3σx¯阈值内。相比之下，模型B表现出明显的性能变化（p < 0.001），所有五个器官在所有7个月内都超过了两个阈值。2σx¯阈值在检测模型A的轻微偏差时更为敏感，而两个阈值都能有效识别模型b的重大偏差。结论监测系统能有效检测出分布外异常值和临床实践变化，为早期检测月度性能下降提供了可靠的框架。

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引用次数: 0

A multi-institutional dummy run on segmentation variability and plan quality of stereotactic body radiotherapy for oligometastatic disease 对低转移性疾病立体定向放射治疗的分割可变性和计划质量的多机构模拟试验

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100857

Hideaki Hirashima , Yukinori Matsuo , Satoshi Ishikura , Mitsuhiro Nakamura , Ikuno Nishibuchi , Daisuke Kawahara , Yoshihisa Shimada , Yoshiro Nakahara , Teiji Nishio , Naoto Shikama , Shun-ichi Watanabe , Isamu Okamoto , Toshiyuki Ishiba , Fumikata Hara , Tadahiko Shien , Takashi Mizowaki

Background and purpose

Oligometastatic disease represents limited metastatic burden, and local ablative therapies such as stereotactic body radiotherapy (SBRT) may improve survival. However, inter-institutional variability in target segmentation and treatment planning can compromise treatment quality. This study aimed to evaluate the segmentation variability and dose distribution quality of SBRT in oligometastatic settings using a multi-institutional dummy run approach.

Methods and materials

Sixty-nine institutions were provided with two anonymized cases of adrenal and spine metastases to delineate targets and organs at risk (OARs) and create intensity-modulated radiotherapy plans following a protocol. Variability was quantified using the Dice similarity coefficient (DSC), Hausdorff distance, and mean distance to agreement. Plan qualities were assessed using the Paddick conformity index, modified gradient index, and a new three-dimensional conformity–gradient index (3D-CGI). Knowledge-based planning (KBP) was applied to explore potential improvements in OAR sparing.

Results

All submitted plans met protocol dose constraints. However, substantial segmentation variability was observed, particularly for the spine case. Among 136 plans, 79% demonstrated acceptable conformity and dose gradients, with 3D-CGI < 6 correlating with favorable distributions. Mean DSC was 0.93 for the clinical target volume and 0.76 for the cauda equina, which showed the highest variability. KBP reduced OAR doses for the adrenal case but showed limited impact for the spine case.

Conclusions

Although dose constraints were achieved, segmentation variability remained substantial, particularly for the cauda equina in the spine case. These findings emphasize inter-institutional differences and the need for standardization and tools to improve SBRT consistency.

背景和目的低转移性疾病代表有限的转移负担，局部消融治疗如立体定向全身放疗（SBRT）可能提高生存率。然而，机构间在目标分割和治疗计划方面的差异会影响治疗质量。本研究旨在通过多机构虚拟试验方法评估SBRT在低转移环境中的分割可变性和剂量分布质量。方法和材料69家机构提供了2例匿名的肾上腺和脊柱转移病例，以划定靶和危险器官（OARs），并根据协议制定调强放疗计划。使用Dice相似系数（DSC）、Hausdorff距离和平均一致距离来量化变异。采用Paddick整合指数、改良的梯度指数和一种新的三维整合梯度指数（3D-CGI）来评估计划质量。应用基于知识的计划（KBP）来探索OAR节约的潜在改进。结果所有提交的方案均满足方案剂量限制。然而，观察到大量的分割变异性，特别是脊柱病例。在136个方案中，79%表现出可接受的符合性和剂量梯度，3D-CGI <； 6与良好的分布相关。临床靶体积的平均DSC为0.93，马尾的平均DSC为0.76，表现出最高的变异性。KBP减少了肾上腺病例的OAR剂量，但对脊柱病例的影响有限。结论虽然达到了剂量限制，但分割的可变性仍然很大，特别是对于脊柱病例的马尾。这些发现强调了机构间的差异以及提高SBRT一致性的标准化和工具的必要性。

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引用次数: 0

A machine learning approach for radiation pneumonitis prediction in elderly esophageal cancer patients by integrating baseline computed tomography radiomics, dosiomics, and clinical characteristics 结合基线计算机断层放射组学、剂量组学和临床特征预测老年食管癌患者放射性肺炎的机器学习方法

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100863

Zhunhao Zheng , Junqiang Chen , Xiaolin Ge , Meng Yan , Ling Li , Qifeng Wang , Xiaomin Wang , Xin Wang , Wenyang Liu , Yonggang Shi , Xiaofeng Wang , Hongyun Shi , Zhilong Yu , Qingsong Pang , Zefen Xiao , Wencheng Zhang

Background and purpose

To integrate clinical characteristics, radiomics, and dosiomics to provide accurate and individualized prediction of radiation pneumonitis (RP) in elderly patients aged 70 and over with esophageal cancer receiving radiotherapy.

Materials and methods

Based on a phase III clinical study (NCT02979691) that included elderly patients with esophageal squamous cell carcinoma (ESCC) who received definitive radiotherapy, we selected a total of 229 patients with available computed tomography (CT) and dose images. Radiomic and dosiomics features were extracted from both lungs. The patients were randomly assigned to either the training group (N = 161) or the test group (N = 68) in a 7:3 ratio. In the training set, logistic regression (LR) was applied to calculate the radiomic score (R score) and dosiomic score (D score). The constructed multivariate LR and ridge regression prediction models were evaluated using the test set. The endpoint of the predictive model is defined as a grade ≥ 2 RP. Discrimination and prediction were assessed by calculating the area under curve (AUC) of the receiver operating characteristic curve and plotting calibration and decision curve analyses (DCA).

Results

The hybrid LR model integrating R score, D score and clinical characteristics had the best clinical applicability. The hybrid model demonstrated superior predictive performance on the test set, achieving an area under the curve (AUC) of 0.76, while the combined clinical and DVH model achieved an AUC of 0.70.

Conclusions

A hybrid model combining radiomics and dosiomics with clinical characteristics showed the best performance for predicting RP.

背景与目的将临床特征、放射组学和剂量组学相结合，为70岁及以上高龄食管癌放疗患者放射性肺炎（RP）的准确、个体化预测提供依据。材料和方法基于一项III期临床研究（NCT02979691），该研究纳入了接受最终放疗的老年食管鳞状细胞癌（ESCC）患者，我们共选择了229例具有可用计算机断层扫描（CT）和剂量图像的患者。从两肺提取放射组学和剂量组学特征。患者按7:3的比例随机分为训练组（N = 161）和试验组（N = 68）。在训练集中，应用logistic回归（LR）计算放射组学评分（R评分）和剂量组学评分（D评分）。使用测试集对构建的多元LR和岭回归预测模型进行评估。预测模型的终点定义为RP≥2级。通过计算受试者工作特性曲线下面积（AUC）和绘制校准和决策曲线分析（DCA）来评估鉴别和预测能力。结果综合R评分、D评分和临床特征的混合型LR模型具有最佳的临床适用性。混合模型在测试集上表现出更好的预测性能，曲线下面积（AUC）为0.76，而临床和DVH联合模型的AUC为0.70。结论放射组学和剂量组学结合临床特征的混合模型预测RP的效果最好。

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引用次数: 0

Workflow evaluation of surface-guided initial patient set-up in radiotherapy 放射治疗中表面引导初始病人设置的工作流程评估

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100877

Mikkel Skaarup, Nikolaj Kylling Gyldenløve Jensen

Background and purpose

The desire to avoid tattooing radiotherapy patients lead us to implement surface-guided initial patient set-up (SGRT). To validate SGRT we investigated setup precision, user attitude, and impact on radiotherapy technician (RTT) workflow.

Materials and methods

During a six-month period, initial setup was investigated on six linear accelerators (Truebeam, Varian), each equipped with a thermo-optical surface camera (ExacTrac Dynamic, Brainlab). Precision was assessed by comparing couch shifts based on x-ray imaging acquired after initial setup and number of x-ray imaging procedures for each fraction to data from the prior year, using a tattoo-based setup. The data was split into subgroups (thoracic, abdominal/pelvic, palliative and miscellaneous (gastrointestinal, head and neck, cranial and extremities)). User attitude and impact on RTT workflow was assessed qualitatively by questionnaire. RTTs were asked to rate how SGRT compared to tattoo-based setup and record the need for manual adjustments of the patient (e.g. pushing, lifting or pulling). Questionnaires were repeated 1.5 years after implementation.

Results

We included 460 patients setup with SGRT, and 468 patients with tattoo-based methods. Median couch shifts and repeated imaging were comparable overall (0.6 cm and 9 % respectively for both setup methods), SGRT performed better for the thoracic and miscellaneous sites subgroups. RTTs preferred SGRT to laser and tattoo initial setup for >90 % of fractions. Manual adjustments were reduced with SGRT (15 % of fractions) compared to tattoo-based (60 % of fractions).

Conclusions

SGRT achieved the same or better precision as tattoo-based initial setup while providing a better workflow and reduced physical adjustments performed by the RTTs by 75 %.

背景和目的为了避免放射治疗患者纹身，我们实施了表面引导初始患者设置（SGRT）。为了验证SGRT，我们调查了设置精度、用户态度和对放疗技术员（RTT）工作流程的影响。材料和方法在六个月的时间里，研究了六个线性加速器（Truebeam, Varian）的初始设置，每个加速器都配备了一个热光学表面摄像机（ExacTrac Dynamic, Brainlab）。通过比较初始设置后获得的x射线成像和每个部分的x射线成像程序数与上一年的数据，使用基于纹身的设置，来评估精度。数据被分成亚组（胸部、腹部/骨盆、姑息治疗和其他（胃肠道、头颈部、颅骨和四肢））。采用问卷法定性评价用户态度及其对RTT工作流程的影响。rtt被要求评价SGRT与基于纹身的设置相比如何，并记录患者手动调整的需要（例如推，举或拉）。调查问卷在实施后1.5年重复进行。结果460例患者采用SGRT， 468例患者采用文身法。中位卧移和重复成像总体上具有可比性（两种设置方法分别为0.6厘米和9%），SGRT在胸部和其他部位亚组中表现更好。对于90%的分数，rtt首选SGRT而不是激光和纹身初始设置。与基于纹身的（60%）相比，SGRT减少了手动调整（15%的分数）。结论ssgrt达到了与基于纹身的初始设置相同或更好的精度，同时提供了更好的工作流程，并将rtt进行的物理调整减少了75%。

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引用次数: 0

Evaluating the quality of multiple automatically produced segmentation variants of the prostate on Magnetic Resonance Imaging scans for brachytherapy 评估近距离放射治疗的磁共振成像扫描中自动生成的多个前列腺分割变体的质量

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100852

Arkadiy Dushatskiy , Peter A.N. Bosman , Karel A. Hinnen , Jan Wiersma , Henrike Westerveld , Bradley R. Pieters , Tanja Alderliesten

Background and Purpose

Recently, we introduced a novel Deep Learning (DL) based (semi-)automatic method for medical image segmentation. Unlike classical DL segmentation methods, it produces multiple segmentation variants (reflecting the variation of manual segmentations) instead of just one. Potentially, with this approach, there is a higher chance that a clinician prefers one of automatically produced segmentation variants. This work focuses on evaluating this method on prostate segmentation in MRI scans used for brachytherapy and investigating its potential clinical usefulness.

Materials and Methods

Three experienced radiation oncologists graded (per-slice and per-scan) segmentations produced by our method, reference segmentations (manually created and used for brachytherapy treatment planning) and segmentations produced by a classical DL method. The study was retrospective and the way the segmentation was generated (our method, classical DL method, or manually) was blinded for the clinicians. The grades reflect the amount of manual correction required. Additionally, the clinicians were asked to rank segmentations to evaluate which one is preferred for each scan. The study was performed on 13 prostate cancer patients.

Results

Segmentations produced by our method are graded as requiring no manual correction in 292/576 (51 %) slices compared to 240/576 (42 %) slices in the case of the segmentations produced by a classical DL method. Furthermore, in fewer slices, 38 (6.6 %) vs. 48 (8.3 %), segmentations by our method were graded as unacceptable.

Conclusion

Our study has demonstrated that deep-learning-based segmentation methods can produce high-quality segmentations. Our method was evaluated better than a classical DL method, indicating the potential for integration into clinical practice.

背景与目的最近，我们提出了一种新的基于深度学习的（半）自动医学图像分割方法。与经典的深度学习分割方法不同，它产生多个分割变量（反映手动分割的变化），而不仅仅是一个。潜在地，使用这种方法，临床医生更倾向于自动生成的分割变体之一的可能性更高。这项工作的重点是评估这种方法在前列腺分割的MRI扫描用于近距离治疗和研究其潜在的临床用途。材料和方法三位经验丰富的放射肿瘤学家对我们的方法生成的分割（每片和每扫描），参考分割（手动创建并用于近距离治疗计划）和经典DL方法生成的分割进行了分级。该研究是回顾性的，分割产生的方式（我们的方法，经典DL方法，或手动）对临床医生是盲目的。这些成绩反映了需要手工改正的数量。此外，临床医生被要求对分割进行排序，以评估哪一个是每次扫描的首选。这项研究是在13名前列腺癌患者身上进行的。结果与经典DL方法产生的分割结果相比，我们的方法产生的分割结果在292/576（51%）片中不需要人工校正，而在240/576（42%）片中不需要人工校正。此外，在较少的切片中，38（6.6%）对48(8.3%)，我们的方法分割被评为不可接受。结论基于深度学习的分割方法可以产生高质量的分割结果。我们的方法被评估为比经典的DL方法更好，表明整合到临床实践的潜力。

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引用次数: 0

Prospective validation of a pretreatment 18F-FDG PET/CT and mean lung dose model for early radiation pneumonitis 18F-FDG预处理PET/CT和平均肺剂量模型对早期放射性肺炎的前瞻性验证

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100844

Maria Thor , Aditya Apte , Milan Grkovski , Charles B. Simone II , Daphna Y. Gelblum , Masoud Zarepisheh , Puneeth Iyengar , Abraham J. Wu , Jacob Y. Shin , Tafadzwa Chaunzwa , Jennifer Ma , David Billing , Mark Dunphy , Jamie E. Chaft , Daniel R. Gomez , Joseph O. Deasy , Narek Shaverdian

Background and purpose

Early onset radiation pneumonitis (RP_Early) after concurrent chemoradiotherapy (cCRT) can lead to consolidation immunotherapy (IO) discontinuation, and poor survival in locally advanced non-small cell lung cancer (LA-NSCLC). This work assessed the external validity of a previously published RP_Early risk model.

Material and methods

The RP_Early risk model utilizes pretreatment 18F-FDG PET/CT imaging of the normal lungs and the mean lung dose (MLD). The 90th percentile of the standardized uptake value (SUV_P90) and the MLD model parameters from the previous derivation cohort (N = 160) were applied in the independent cohort (50 consecutive LA-NSCLC patients treated with cCRT and IO) where model performance was evaluated (area under the receiver-operating characteristic curve (AUC), p-values, and the Hosmer-Lemeshow test (pHL)).

Results

Seven patients (14 %) developed RP_Early. Model performance of the previously developed SUV_P90 and MLD model improved with re-fitting (AUC = 0.76 vs. 0.72; p = 0.01 vs. 0.10; pHL = 0.66 vs. 0.94). Above a clinically desirable 10 % predicted RP_Early, after refitting model coefficients in the combined derivation and validation cohorts (N = 210), the MLD was 13 ± 2.2 EQD2₃ Gy (SUV_P90 = 1.2 ± 0.3) above the RP_Early risk threshold vs. 8.5 ± 2.6 EQD2₃ Gy (0.9 ± 0.2) below the threshold. For an SUV_P90 of 1.1 and an MLD of 11 Gy EQD2₃ Gy, 25/27 patients developing RP_Early were captured.

Conclusion

The previously developed SUV_P90 and MLD-based risk model for RP_Early demonstrated a high probability to correctly predict RP_Early in the independent cohort. This now validated RP_Early risk model with derived high-risk indications could enable personalized thoracic RT planning to reduce the risk of RP_Early and of discontinuing life-prolonging IO post-cCRT.

背景和目的同步放化疗（cCRT）后早发性放射性肺炎（RPEarly）可导致局部晚期非小细胞肺癌（LA-NSCLC）的巩固免疫治疗（IO）中断和生存率低。这项工作评估了先前发表的RPEarly风险模型的外部有效性。材料和方法RPEarly risk模型采用预处理的18F-FDG PET/CT正常肺成像和平均肺剂量（MLD）。在独立队列（50例连续接受cCRT和IO治疗的LA-NSCLC患者）中，采用标准化摄取值（SUVP90）的第90百分位和先前衍生队列（N = 160）的MLD模型参数，评估模型性能（接受者-工作特征曲线下面积（AUC）、p值和Hosmer-Lemeshow检验（pHL））。结果早期发病7例（14%）。先前开发的SUVP90和MLD模型的模型性能通过重新拟合得到改善（AUC = 0.76 vs. 0.72; p = 0.01 vs. 0.10; pHL = 0.66 vs. 0.94）。在推导和验证联合队列（N = 210）中修正模型系数后，在临床所需的10%以上预测RPEarly， MLD比RPEarly风险阈值高13±2.2 EQD23 Gy (SUVP90 = 1.2±0.3)，比阈值低8.5±2.6 EQD23 Gy（0.9±0.2）。SUVP90为1.1，MLD为11 Gy EQD23 Gy，捕获了25/27的早期发展患者。结论先前建立的基于SUVP90和mld的RPEarly风险模型在独立队列中正确预测RPEarly的概率很高。现在，这个经过验证的RPEarly风险模型及其衍生的高风险适应症可以实现个性化的胸部RT计划，以降低RPEarly的风险和ccrt后停止延长生命的IO的风险。

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引用次数: 0

Leveraging dixon-based magnetic resonance imaging for pelvic bone marrow imaging in radiotherapy 利用基于dixon的磁共振成像在放射治疗中的盆腔骨髓成像

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100841

Chuyan Wang , Haoping Xu , Zhenkui Wang , Li Tong , Xijing Zhang , Fuhua Yan , Jiayi Chen , Yingli Yang

Background and purpose

Pelvic radiotherapy-induced bone marrow (BM) damage adversely affects patient prognosis. Progress in BM-sparing radiotherapy is limited by the lack of standardized BM quantification and the inherent constraints of magnetic resonance spectroscopy (MRS), the current gold standard for BM magnetic resonance imaging (MRI). Proton density fat fraction (PDFF), derived from DIXON-based MRI, has emerged as an imaging biomarker for detecting BM changes. This study evaluated the potential of DIXON-based MRI in pelvic BM for radiotherapy.

Materials and methods

Three existing DIXON-based techniques were optimized and compared to establish clinical protocols. In vitro measurements were performed using fat phantoms calibrated against thermogravimetric analysis, while in vivo measurements were based on data from 30 volunteers with MRS serving as the reference standard. Quantitative accuracy was assessed using mean absolute error (MAE), repeatability via intra-class correlation coefficients (ICCs), and image quality using an ACR phantom.

Results

Comprehensive evaluation identified optimal parameters for each DIXON-based sequence. For in vitro measurements, the MAE for MRS was 3.5 % and the highest MAE across three optimized DIXON-based sequences was 5.9 %. For in vivo measurements, linear regressions between MRS and each of the optimized DIXON-based sequence resulted in R² ≥ 0.93 and MAE ≤ 7.6 %. All three optimized DIXON-based sequences demonstrated high repeatability (ICCs ≥ 0.97) and clearly visualized BM with varying fat fractions, with no consistently outperforming in image quality.

Conclusion

For BM assessment, this study demonstrated DIXON-based PDFF quantification achieved high accuracy, repeatability, and image quality, supporting its potential for radiotherapy.

背景与目的盆腔放疗所致的骨髓损伤对患者预后有不利影响。保留脑基放射治疗的进展受到缺乏标准化脑基量化和磁共振波谱（MRS）固有约束的限制，磁共振波谱是目前脑基磁共振成像（MRI）的金标准。质子密度脂肪分数（PDFF）源于基于dixon的MRI，已成为检测BM变化的成像生物标志物。本研究评估了DIXON-based MRI在骨盆BM放射治疗中的潜力。材料与方法对现有的三种基于dixon的技术进行优化和比较，建立临床方案。体外测量使用根据热重分析校准的脂肪模型进行，而体内测量基于30名志愿者的数据，以MRS作为参考标准。使用平均绝对误差（MAE）评估定量准确性，通过类内相关系数（icc）评估重复性，使用ACR模型评估图像质量。结果综合评价确定了各dixon序列的最优参数。对于体外测量，MRS的MAE为3.5%，三个优化的基于dixon的序列的最高MAE为5.9%。在体内测量中，MRS与每个优化的基于dixon的序列之间的线性回归结果为R2≥0.93,MAE≤7.6%。所有三个优化的基于dixon的序列都具有高重复性（ICCs≥0.97），并且清晰地显示了不同脂肪含量的BM，并且在图像质量上没有一致的表现。结论本研究表明，基于dixon的PDFF定量方法具有较高的准确性、重复性和图像质量，支持其在放疗中的潜力。

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引用次数: 0

New modalities for ultra-high dose rate irradiation and FLASH experiments 超高剂量率辐照和FLASH实验的新模式

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100861

Gabriel Adrian, Raphaël Moeckli, Elke Beyreuther, Ludvig P. Muren, Brita Singers Sørensen

引用次数: 0

First implementation of photon-counting dector computed tomography for optimizing segmentation in head-and-neck cancer radiotherapy 首次实现光子计数检测器计算机断层扫描优化头颈部肿瘤放疗的分割

IF 3.3 Q2 ONCOLOGY

Physics and Imaging in Radiation Oncology

Pub Date : 2025-10-01 DOI: 10.1016/j.phro.2025.100864

Niccolò Bertini , Hubert S. Gabryś , Hatem Alkadhi , Lotte Wilke , Patrick Wohlfahrt , Serena Psoroulas , Eugenia Vlaskou , Laura Motisi , Matthias Guckenberger , Stephanie Tanadini-Lang , Panagiotis Balermpas

Background and purpose

Photon-counting detector computed tomography (PCD-CT) offers advancements over conventional energy-integrating detector computed tomography (EID-CT). This study is the first to investigate the use of PCD-CT for delineation purposes.

Materials and methods

Twelve patients with head-and-neck cancer were prospectively included. Delineation of clinical target volume (CTV) and organs at risk (OARs) was performed by three physicians using EID-CT (120 kVp) and PCD-CT at virtual monoenergetic levels of 140 keV and 50 keV. Segmentation accuracy was assessed and contouring-confidence was rated.

Results

The ratio of the mean computed tomography dose index (CTDI) for EID-CT/PCD-CT for all patients was 2.72. The study revealed high inter-observer agreement for the mandible, oral cavity, parotid glands, and submandibular glands, with DSCs exceeding 0.8 across both EID-CT and PCD-CT. No differences in delineation agreement were observed, while a significant improvement was found for the lips (p = 0.001) and oral cavity (p = 0.003) when combining 140 keV and 50 keV images in PCD-CT compared to EID-CT. PCD-CT outperformed EID-CT in terms of contouring confidence.

Conclusion

The study established the feasibility of PCD-CT for radiotherapy planning. PCD-CT-based delineation provides results comparable to EID-CT, with the added advantages of reduced radiation dose, improved image quality and higher delineation confidence. Significant improvements in delineating specific structures, such as the lips and oral cavity, were observed when combining multiple energy levels in PCD-CT.

背景和目的光子计数检测器计算机断层扫描（PCD-CT）是传统能量积分检测器计算机断层扫描（EID-CT）的进步。本研究首次探讨了利用PCD-CT进行圈定的目的。材料与方法前瞻性纳入12例头颈癌患者。临床靶体积（CTV）和危险器官（OARs）由三名医生在140 keV和50 keV的虚拟单能水平下使用EID-CT （120 kVp）和PCD-CT进行描绘。评估分割精度和轮廓置信度。结果所有患者的EID-CT/PCD-CT平均ct剂量指数（CTDI）之比为2.72。该研究显示，下颌骨、口腔、腮腺和下颌下腺的观察者间一致性很高，在EID-CT和PCD-CT上，dsc均超过0.8。与EID-CT相比，结合140 keV和50 keV的PCD-CT图像，发现嘴唇（p = 0.001）和口腔（p = 0.003）的描画一致性没有差异。在轮廓置信度方面，PCD-CT优于EID-CT。结论本研究确立了PCD-CT辅助放疗规划的可行性。基于pcd - ct的成像结果可与EID-CT媲美，并且具有辐射剂量降低、图像质量改善和成像可信度更高的优点。在PCD-CT结合多个能量水平时，观察到在描绘特定结构（如嘴唇和口腔）方面有显着改善。

{"title":"First implementation of photon-counting dector computed tomography for optimizing segmentation in head-and-neck cancer radiotherapy","authors":"Niccolò Bertini , Hubert S. Gabryś , Hatem Alkadhi , Lotte Wilke , Patrick Wohlfahrt , Serena Psoroulas , Eugenia Vlaskou , Laura Motisi , Matthias Guckenberger , Stephanie Tanadini-Lang , Panagiotis Balermpas","doi":"10.1016/j.phro.2025.100864","DOIUrl":"10.1016/j.phro.2025.100864","url":null,"abstract":"<div><h3>Background and purpose</h3><div>Photon-counting detector computed tomography (PCD-CT) offers advancements over conventional energy-integrating detector computed tomography (EID-CT). This study is the first to investigate the use of PCD-CT for delineation purposes.</div></div><div><h3>Materials and methods</h3><div>Twelve patients with head-and-neck cancer were prospectively included. Delineation of clinical target volume (CTV) and organs at risk (OARs) was performed by three physicians using EID-CT (120 kVp) and PCD-CT at virtual monoenergetic levels of 140 keV and 50 keV. Segmentation accuracy was assessed and contouring-confidence was rated.</div></div><div><h3>Results</h3><div>The ratio of the mean computed tomography dose index (CTDI) for EID-CT/PCD-CT for all patients was 2.72. The study revealed high inter-observer agreement for the mandible, oral cavity, parotid glands, and submandibular glands, with DSCs exceeding 0.8 across both EID-CT and PCD-CT. No differences in delineation agreement were observed, while a significant improvement was found for the lips (p = 0.001) and oral cavity (p = 0.003) when combining 140 keV and 50 keV images in PCD-CT compared to EID-CT. PCD-CT outperformed EID-CT in terms of contouring confidence.</div></div><div><h3>Conclusion</h3><div>The study established the feasibility of PCD-CT for radiotherapy planning. PCD-CT-based delineation provides results comparable to EID-CT, with the added advantages of reduced radiation dose, improved image quality and higher delineation confidence. Significant improvements in delineating specific structures, such as the lips and oral cavity, were observed when combining multiple energy levels in PCD-CT.</div></div>","PeriodicalId":36850,"journal":{"name":"Physics and Imaging in Radiation Oncology","volume":"36 ","pages":"Article 100864"},"PeriodicalIF":3.3,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614338","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

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