Physica Medica-European Journal of Medical Physics最新文献_第2页

Mean glandular dose estimation in population-based breast screening in Queensland, Australia: Retrospective comparison of TG282 and Dance models (2022–2025) 澳大利亚昆士兰州以人群为基础的乳腺筛查的平均腺体剂量估计：TG282和Dance模型的回顾性比较（2022-2025）。

IF 2.7 3区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Physica Medica-European Journal of Medical Physics

Pub Date : 2026-01-06 DOI: 10.1016/j.ejmp.2026.105722

Mandeep Louhan, Ioannis Delakis

Purpose

To compare mean glandular dose (MGD) estimates using the Dance and AAPM/EFOMP TG282 methodologies in a large breast screening dataset from Queensland, Australia and to establish population-level baselines that can inform future analysis and development of diagnostic reference levels (DRLs).

Methods

This retrospective study analysed 1,280,343 two-dimensional mammographic exposures acquired between April 2022 and March 2025 on Hologic 3Dimensions and Selenia Dimensions, and Siemens MAMMOMAT Inspiration and Revelation systems. MGD was estimated using Dance and AAPM/EFOMP TG282 methodologies. Percentage differences were calculated per compressed breast thickness (CBT) interval and compared using the Wilcoxon signed-rank test. Volumetric breast density (VBD) was estimated using Volpara software.

Results

AAPM/EFOMP TG282 produced lower MGD estimates than Dance, with overall reduction of 24.4 % for craniocaudal (CC) views and 23.5 % for mediolateral oblique (MLO) views (p < 0.001). Differences were minimal at low CBT but increased with thickness, with discontinuities corresponding to spectral transitions in automatic exposure control (AEC) mode of operation. Mean CBT values (56.2 mm CC, 59.2 mm MLO) were comparable to previously reported values. VBD distributions aligned closely with AAPM/EFOMP TG282 reference values.

Conclusions

The TG282 methodology yielded lower MGD estimates than Dance, consistent with international findings and reflecting more anatomically realistic breast modelling. Results emphasise the importance of dosimetry methodology and CBT reference values in setting DRLs. The data provide population-level baselines to support future national DRLs for mammography in Australia.

目的：比较来自澳大利亚昆士兰州的大型乳腺筛查数据集中使用Dance和AAPM/EFOMP TG282方法的平均腺剂量（MGD）估算值，并建立人群水平基线，为未来的分析和诊断参考水平（drl）的制定提供信息。方法：本回顾性研究分析了2022年4月至2025年3月期间在Hologic 3Dimensions和Selenia Dimensions以及Siemens MAMMOMAT启发和启示系统上获得的1,280,343张二维乳房x线片。使用Dance和AAPM/EFOMP TG282方法估计MGD。计算每个压缩乳房厚度（CBT）间隔的百分比差异，并使用Wilcoxon符号秩检验进行比较。使用Volpara软件估计乳腺体积密度（VBD）。结果：AAPM/EFOMP TG282产生的MGD估计比Dance低，颅侧（CC）视图总体降低24.4%，中外侧斜位（MLO）视图总体降低23.5% (p结论：TG282方法产生的MGD估计比Dance低，与国际研究结果一致，反映了更真实的解剖学乳房模型。结果强调了剂量学方法学和CBT参考值在确定drl中的重要性。这些数据提供了人口水平的基线，以支持澳大利亚未来的全国乳房x光检查drl。

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引用次数: 0

Risk estimations of radiation induced malignancies in rectum and bladder following radiotherapy of prostate carcinoma 前列腺癌放疗后直肠和膀胱放射诱发恶性肿瘤的风险评估。

IF 2.7 3区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Physica Medica-European Journal of Medical Physics

Pub Date : 2026-01-06 DOI: 10.1016/j.ejmp.2026.105714

Brigitta Timea Herczeg , Ákos Sudár , Rita Ortutay , Péter Ágoston , Tibor Major , Zoltán Takácsi-Nagy , Csilla Pesznyák

Purpose

The purpose of this study was to estimate the risks of radiation-induced rectal and bladder cancers in the case of standard fractionated and hypofractionated radiotherapy for prostate carcinoma using volumetric modulated arc therapy and intensity modulated radiotherapy.

Methods

Three plans were generated for twenty-five patients, employing both conventional two-step sequential and simultaneous integrated boost approaches, with prescribed doses of 78 Gy in 39 fractions for CONV-VMAT and 70 Gy in 28 fractions for SIB techniques. The risks of secondary malignancies were estimated based on the organ equivalent doses (OED) and excess absolute risk (EAR) for the bladder and rectum using two radiobiological models: linear-plateau (Plat), and mechanistic (Mech) models.

Results

Statistically higher OEDs were observed between CONV-VMAT and both SIB-IMRT and SIB-VMAT using Plat (p = 0.012 and p = 0.000) and Mech models (p = 0.000 and p = 0.000) in the case of the rectum. In case of the bladder significantly higher OED values were found when compared CONV-VMAT with SIB-IMRT and SIB-VMAT using Plat model (p = 0.035 and p = 0.008), but no significant difference when analyzed using Mech model (p = 0.470).

Conclusion

These findings highlight the potential benefits of these radiotherapy techniques, suggesting that SIB-VMAT and SIB-IMRT may enhance organ sparing while mitigating long-term oncogenic risks. The study underscores the importance of refining treatment strategies to optimize prostate cancer outcomes while minimizing collateral risks.

目的：本研究的目的是评估前列腺癌标准分次放疗和低分次放疗使用体积调制电弧治疗和强度调制放疗的风险。方法：为25例患者制定了三个计划，采用传统的两步顺序和同时综合增强方法，convv - vmat技术的处方剂量为78 Gy，分为39个分量，SIB技术的处方剂量为70 Gy，分为28个分量。继发性恶性肿瘤的风险是基于器官等效剂量（OED）和膀胱和直肠的超额绝对风险（EAR），使用两种放射生物学模型：线性平台模型（Plat）和机械模型（Mech）。结果：在直肠的情况下，使用Plat （p = 0.012和p = 0.000）和Mech模型（p = 0.000和p = 0.000）， convv - vmat与sibb - imrt和sibb - vmat之间的oed均有统计学意义上的升高。在膀胱中，使用Plat模型比较convt - vmat与sibt - imrt和sibt - vmat时，发现OED值显著高于对照组（p = 0.035和p = 0.008），而使用Mech模型分析时，差异无统计学意义（p = 0.470）。结论：这些发现强调了这些放疗技术的潜在益处，表明sibb - vmat和sibb - imrt可能增强器官保留，同时减轻长期致癌风险。该研究强调了改进治疗策略以优化前列腺癌预后同时最小化附带风险的重要性。

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引用次数: 0

MRI artefacts and fat suppression near implants: A Multi-material Comparative evaluation at 0.31, 0.55, 1.5 and 3 Tesla MRI伪影和植入物附近的脂肪抑制：在0.31,0.55,1.5和3特斯拉下的多材料比较评估。

IF 2.7 3区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Physica Medica-European Journal of Medical Physics

Pub Date : 2026-01-06 DOI: 10.1016/j.ejmp.2026.105721

L. Buchmann , H. Yusuff , G. Bierry , T. Willaume , J.P. Dillenseger

Background

Metallic implants frequently induce MRI artefacts, impairing diagnostic accuracy. Conventional reduction methods such as VAT and SEMAC mitigate artefacts but increase acquisition times and image blurring. Recent technological advances have renewed interest in low-field MRI as a potential alternative.

Methods

Three custom-designed phantoms containing four implants (ceramic femoral head, cobalt–chromium femoral head, titanium screw, stainless steel screw) were scanned at 0.31 T, 0.55 T, 1.5 T, and 3 T. Protocols included T1-FSE, T2-FSE, and STIR sequences with/without VAT and SEMAC. Six blinded readers (radiologists, radiographers, physicist) assessed artefact size, distortion, blurring, noise, and fat suppression using a 5-point Likert scale. Quantitative artefact areas were measured using MATLAB-based segmentation, expressed as absolute values and relative reductions compared with 3 T.

Results

Fifty-four sequences (1968 scores) were analysed. Artefact size decreased by 63–80 % at 0.31 T and 0.55 T compared with 3 T and by 60–77 % compared with 1.5 T. Fat suppression was consistently effective at low fields but less so at 1.5 T and 3 T unless VAT or SEMAC was used. These sequences further reduced artefacts at high fields but introduced blurring and increased acquisition times. Qualitative and quantitative findings were concordant across all readers.

Conclusion

Low-field MRI markedly reduces metal-induced artefacts while preserving clinically acceptable scan times and fat suppression performance. Integrating low-field systems into clinical workflows could complement standard 1.5 T and 3 T imaging, especially for patients with metallic implants.

背景：金属植入物经常引起MRI伪影，影响诊断的准确性。传统的减少方法，如VAT和SEMAC减轻了伪影，但增加了采集时间和图像模糊。最近的技术进步重新引起了人们对低场核磁共振成像作为潜在替代方案的兴趣。方法：在0.31 T、0.55 T、1.5 T和3t下扫描三个定制设计的假体（陶瓷股骨头、钴铬股骨头、钛螺钉、不锈钢螺钉），包括T1-FSE、T2-FSE和STIR序列（含/不含VAT和SEMAC）。六位盲眼读者（放射科医生、放射技师、物理学家）使用5分李克特量表评估伪影大小、失真、模糊、噪音和脂肪抑制。定量伪影区域使用基于matlab的分割进行测量，表示为绝对值和与3 t相比的相对减少。结果：分析了54个序列（1968分数）。与3 T相比，在0.31 T和0.55 T时，伪迹大小减少了63- 80%，与1.5 T相比减少了60- 77%。脂肪抑制在低田一直有效，但在1.5 T和3 T时效果较差，除非使用VAT或SEMAC。这些序列进一步减少了高场的伪影，但引入了模糊和增加了采集时间。所有读者的定性和定量研究结果一致。结论：低场MRI在保留临床可接受的扫描时间和脂肪抑制性能的同时，显著减少了金属诱发的伪影。将低场系统集成到临床工作流程中可以补充标准的1.5 T和3t成像，特别是对于金属植入物患者。

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引用次数: 0

Validation of the Tena pregnancy phantom and fetal dose assessment in proton scanning beam therapy 质子扫描束治疗中Tena妊娠幻影和胎儿剂量评估的验证。

IF 2.7 3区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Physica Medica-European Journal of Medical Physics

Pub Date : 2026-01-06 DOI: 10.1016/j.ejmp.2026.105718

Natalia Mojżeszek , Hrvoje Brkić , Gabriela Foltyńska , Olivier Van Hoey , Hubert Jabłoński , Mladen Kasabasic , Renata Kopeć , Katarzyna Krzempek , Monika Lipa , Andrea Matamoros , Monika Radolińska , Marzena Rydygier , Tomasz Skóra , Carlos Granja , Liliana Stolarczyk , Dawid Krzempek , Marijke De Saint-Hubert

Background

Intensity modulated proton therapy (IMPT) is the preferred option during pregnancy, as it reduces out-of-field doses compared to photon techniques. A physical pregnancy phantom was validated for in-field proton dosimetry and used to assess fetal dose across four IMPT plans.

Methods

The 18-week pregnancy Tena phantom was composed of bone, soft tissue, and lung substitutes. Proton relative stopping power (RSP) for Tena tissues was measured and compared with treatment planning system (TPS) and Monte Carlo (MC) calculations. Experimental TPS dose verification was performed using gamma index (GI). Fetal dose was measured for IMPT of glioma, Hodgkin lymphoma without (HL) and with a range shifter (HL-RS), and submandibular gland (neck) cancer using a Timepix and bubble detectors.

Results

Differences between TPS-assigned and MC-simulated relative to the measured RSP values were up to −7.4 %. GI(3 %/3 mm) values were above 93.38 %. The neutron dose equivalent in the fetus position ranged between 2.5 and 49.4 µSv/Gy(RBE) for glioma and HL-RS plans, respectively. The HL plan reduced neutron dose equivalent to 15.8 µSv/Gy(RBE), while for the neck 20 µSv/Gy(RBE) was measured. Neutrons were dominant with ∼ 80 % contribution to the total dose equivalent. A summed fetal dose was calculated considering the prescribed dose per treatment and ranged between 0.17 mSv and 1.89 mSv for glioma and HL-RS, respectively.

Conclusions

The Tena phantom is suitable for proton dosimetry and enables accurate TPS calculations. The use of a range shifter increased the fetal dose by more than threefold. Fetal doses for all IMPT plans remained below 2 mSv.

背景：强度调制质子治疗（IMPT）是怀孕期间的首选，因为与光子技术相比，它减少了场外剂量。物理妊娠幻影被验证用于现场质子剂量测定，并用于评估四个IMPT计划中的胎儿剂量。方法：采用骨、软组织、肺代用品组成的18周妊娠Tena假体。测量Tena组织的质子相对停止功率（RSP），并与治疗计划系统（TPS）和蒙特卡罗（MC）计算进行比较。实验用伽马指数（GI）进行TPS剂量验证。使用Timepix和气泡检测器测量神经胶质瘤、无霍奇金淋巴瘤（HL）和带范围移位器（HL- rs）和颌下腺（颈部）癌的胎儿IMPT剂量。结果：相对于测量的RSP值，tps分配和mc模拟之间的差异高达- 7.4%。GI值（3% /3 mm）在93.38%以上。胶质瘤组和HL-RS组胎儿位置的中子当量剂量分别在2.5 ~ 49.4µSv/Gy（RBE）之间。HL方案减少了相当于15.8µSv/Gy（RBE）的中子剂量，而颈部则减少了20µSv/Gy（RBE）。中子占主导地位，对总剂量当量的贡献为~ 80%。根据每次治疗的规定剂量计算胎儿总剂量，胶质瘤和HL-RS的剂量范围分别在0.17毫西弗和1.89毫西弗之间。结论：Tena模体适用于质子剂量学，能准确计算TPS。范围移位器的使用使胎儿的剂量增加了三倍以上。所有IMPT计划的胎儿剂量保持在2毫西弗以下。

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引用次数: 0

Utility of respiratory motion correction and effects on dosimetry in imaging with integrated Y-90 PET/MRI after radioembolization of liver tumors 肝肿瘤放射栓塞后Y-90 PET/MRI综合成像中呼吸运动矫正的应用及剂量学的影响

IF 2.7 3区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Physica Medica-European Journal of Medical Physics

Pub Date : 2026-01-05 DOI: 10.1016/j.ejmp.2026.105717

Burak Demir , Cigdem Soydal , Irem Mesci , Emre Can Celebioglu , Mehmet Sadik Bilgic , Digdem Kuru Oz , Nuriye Ozlem Kucuk

Purpose

In this study we aimed to investigate the utility of respiratory motion correction using the Q.Static algorithm in integrated Y-90 PET/MR imaging and its impact on dosimetric accuracy, image quality, and dose-volume histograms following radioembolization of the liver tumors.

Methods

This retrospective single-center analysis included 23 patients treated with Y-90 resin microspheres and imaged with Y-90 PET/MRI. Respiratory motion-corrected (Q.Static) and standard non-corrected PET reconstructions were compared for dosimetric variables, image quality (signal-to-noise ratio, SNR), and activity quantification. Tumor dose-volume histograms (D1–D99) and absorbed doses were calculated with absolute quantification and local dose deposition method. Bland-Altman plots and regression analyses were employed to assess differences between the two methods and investigate correlations with tumor volume.

Results

Q.Static sequences resulted in 7.08 % (95 % CI: [+4.82 %] – [+9.34 %]) higher tumor, 9.38 % (95 % CI: [+7.55 %] – [+10.67 %]) higher normal tissue absorbed doses compared to standard reconstructions, resulting in similar T/N ratios. In addition, Q.Static images demonstrated significantly higher D1, D5, and D10 values but lower D90 and D95 values. SNR was 33.62 % lower, and extrahepatic activity was 46.65 % higher in Q.Static sequences, reflecting noise-related degradation. Tumor volume significantly influenced dose variability, with smaller lesions showing greater differences between methods.

Conclusion

Respiratory motion correction in Y-90 PET/MRI may improve contrast and dose quantification in smaller lesions but may reduce image quality in low-activity cases due to noise. While promising for accurate dosimetry, its impact on clinical outcomes and response prediction warrants further studies.

目的在本研究中，我们旨在探讨使用Q.Static算法在Y-90 PET/MR综合成像中的呼吸运动校正的效用及其对放射栓塞肝肿瘤后剂量学准确性、图像质量和剂量-体积直方图的影响。方法回顾性分析23例经Y-90树脂微球治疗并经Y-90 PET/MRI成像的患者。比较呼吸运动校正（Q.Static）和标准非校正PET重建的剂量变量、图像质量（信噪比，SNR）和活动量化。采用绝对定量法和局部剂量沉积法计算肿瘤剂量-体积直方图（D1-D99）和吸收剂量。采用Bland-Altman图和回归分析评估两种方法之间的差异，并研究与肿瘤体积的相关性。结果：与标准重建相比，静态序列导致7.08% （95% CI:[+ 4.82%] ~[+ 9.34%]）的肿瘤增加，9.38% （95% CI:[+ 7.55%] ~[+ 10.67%]）的正常组织吸收剂量增加，T/N比相似。另外，q .静态图像显示D1、D5和D10值明显升高，D90和D95值明显降低。Q.Static序列的信噪比降低了33.62%，肝外活性提高了46.65%，反映了噪声相关的降解。肿瘤体积显著影响剂量变异性，病灶越小，两种方法差异越大。结论Y-90 PET/MRI呼吸运动校正可改善小病变的对比和剂量量化，但在低活动性病例中，由于噪声的影响，可能会降低图像质量。虽然有希望进行准确的剂量测定，但其对临床结果和反应预测的影响值得进一步研究。

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引用次数: 0

Using hydrated electron temporal measurement as dosimetry of individual electron FLASH beam pulses 利用水合电子时间测量作为单个电子闪光束脉冲的剂量测定。

IF 2.7 3区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Physica Medica-European Journal of Medical Physics

Pub Date : 2026-01-05 DOI: 10.1016/j.ejmp.2026.105725

Xu Cao , Aubrey Parks , William Thomas , Matthew S. Reed , Wesley S. Culberson , Brian W. Pogue

Purpose

This study explores the use of hydrated electron absorbance from water radiolysis as a real-time, tissue-equivalent dosimetry method for radiotherapy. While promising, its behavior under ultrahigh dose rates typical of FLASH radiotherapy remains unclear. We investigated the relationship between radiation dose and hydrated electron optical absorption under FLASH conditions.

Methods

Pure water in a quartz cuvette was irradiated with 9 MeV ultra-high dose rate (UHDR) electron beams, and transient absorbance profiles of hydrated electrons were measured using a multi-pass optical technique. The absorbance per unit radiation dose was quantified for each individual pulse and validated by radiochromic EBT-XD film.

Results

The cumulative absorbance of hydrated electrons showed an inconsistent linear relationship with dose per pulse, but normalization by pulse width revealed a strong linear correlation with instantaneous dose rate. This enabled accurate pulse dose determination by multiplying the instantaneous dose rate by the known pulse width. Dose measurements obtained through hydrated electron detection showed strong agreement with film dosimetry within a 10 % margin across a wide range of average dose rates, from 32.7 Gy/s to 392.4 Gy/s.

Conclusion

We present a hydrated electron-based method for indirect, pulse-resolved dose quantification in FLASH radiotherapy. The agreement between the calculated dose and radiochromic EBT-XD film measurements suggests that this approach holds promise for developing tissue-equivalent dosimeters for FLASH radiotherapy applications.

目的：本研究探讨利用水合电子吸收作为一种实时的、组织等效的放射剂量测定方法。虽然很有希望，但它在典型的FLASH放疗的超高剂量率下的行为仍不清楚。研究了FLASH条件下辐射剂量与水合电子光吸收的关系。方法：用9 MeV超高剂量率（UHDR）电子束照射石英试管中的纯水，采用多通光学技术测量水合电子的瞬态吸收谱。对每个脉冲的单位辐射剂量吸光度进行了量化，并通过放射显色EBT-XD薄膜进行了验证。结果：水合电子的累积吸光度与单脉冲剂量呈不一致的线性关系，但脉冲宽度归一化与瞬时剂量率呈强烈的线性关系。这使得通过将瞬时剂量率乘以已知脉冲宽度来精确测定脉冲剂量成为可能。通过水合电子检测获得的剂量测量结果显示，在32.7 Gy/s至392.4 Gy/s的广泛平均剂量率范围内，剂量测量结果与膜剂量法的一致性在10%以内。结论：我们提出了一种基于水合电子的间接、脉冲分辨剂量定量方法。计算剂量和放射致色EBT-XD薄膜测量之间的一致性表明，这种方法有望开发用于FLASH放疗应用的组织等效剂量计。

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引用次数: 0

Predicting patient setup shifts in daily radiotherapy using machine learning on phantom-based CBCT and kV/MV data 使用基于幻象的CBCT和kV/MV数据的机器学习预测患者在日常放疗中的设置变化

IF 2.7 3区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Physica Medica-European Journal of Medical Physics

Pub Date : 2026-01-01 DOI: 10.1016/j.ejmp.2025.105711

Anuj Kumar , Sandeep Singh , Supratik Sen , Abhay Kumar Singh , Dipesh , Benoy Kumar Singh , Manindra Bhushan , Soniya Pal , Munish Gairola

Purpose

This study investigates whether machine learning models trained exclusively on RUBY phantom shift data from CBCT and kV/MV imaging can accurately predict daily patient setup shifts in Head & Neck radiotherapy.

Methods

A total of 12,600 matched imaging fractions from Head & Neck treatments were analysed, each comprising six input features (shifts in X, Y, Z from CBCT and kV/MV imaging) and three output variables (X, Y, Z patient shifts relative to planning CT). Eight regression models were evaluated: Random Forest, AdaBoost, Gradient Boosting, XGBoost, LightGBM, K-Nearest Neighbors, Support Vector Regressor, and Multilayer Perceptron. Performance metrics included mean absolute error (MAE), root mean square error (RMSE),coefficient of determination (R²),and prediction accuracy within ±0.5 mm and ±1 mm.

Results

The Random Forest, XGBoost, and LightGBM models achieved the best performance, each with MAE ≈ 0.254 mm, RMSE ≈ 0.510 mm, and R² ≈ 0.79 across all axes. These models also achieved mean accuracies of 87.9 % within ±0.5 mm and 93.6 % within ±1 mm. Ensemble tree-based methods outperformed other approaches, with AdaBoost showing the lowest accuracy. Feature importance analysis identified CBCT Y and Z phantom shifts as the strongest predictors, reflecting the superior geometric fidelity of volumetric imaging in capturing translational deviations. CBCT-derived features contributed the majority of predictive power, particularly in lateral and longitudinal directions, while kV/MV shifts had relatively lower influence.

Conclusion

Phantom-based machine learning models can accurately predict daily setup deviations in Head & Neck radiotherapy with submillimetre precision. This approach could enhance adaptive workflows, support selective imaging protocols, and enable automated pre-treatment verification, thereby improving both treatment efficiency and patient safety.

目的：本研究探讨仅使用CBCT和kV/MV成像的RUBY幻影位移数据训练的机器学习模型能否准确预测头颈部放疗患者的每日移位。方法对来自头颈部治疗的12600个匹配的成像分数进行分析，每个分数包括6个输入特征（来自CBCT和kV/MV成像的X、Y、Z偏移）和3个输出变量（X、Y、Z患者相对于计划CT的偏移）。评估了8种回归模型：随机森林、AdaBoost、梯度增强、XGBoost、LightGBM、k近邻、支持向量回归和多层感知器。性能指标包括平均绝对误差（MAE）、均方根误差（RMSE）、决定系数（R2）以及在±0.5 mm和±1 mm范围内的预测精度。结果Random Forest、XGBoost和LightGBM模型在各轴上的MAE≈0.254 mm, RMSE≈0.510 mm, R2≈0.79，表现最佳。这些模型在±0.5 mm范围内的平均精度为87.9%，在±1 mm范围内的平均精度为93.6%。基于集成树的方法优于其他方法，AdaBoost显示出最低的准确性。特征重要性分析确定CBCT Y和Z影移是最强的预测因子，反映了体积成像在捕获平移偏差方面的优越几何保真度。cbct衍生的特征贡献了大部分预测能力，特别是在横向和纵向上，而kV/MV变化的影响相对较低。结论基于幻影的机器学习模型能够准确预测头颈部放疗的日常设置偏差，精度达到亚毫米级。这种方法可以增强自适应工作流程，支持选择性成像协议，并实现自动治疗前验证，从而提高治疗效率和患者安全性。

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引用次数: 0

Guide for quality control and safety of external radiotherapy treatment planning systems and treatment plans 外部放射治疗计划系统和治疗方案的质量控制和安全指南

IF 2.7 3区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Physica Medica-European Journal of Medical Physics

Pub Date : 2026-01-01 DOI: 10.1016/j.ejmp.2025.105699

Alejandro García-Romero , Montserrat Baeza-Trujillo , Antonio Teijeiro-García , Francisco Clemente-Gutiérrez , Daniel Morera-Cano , Víctor Hernández-Masgrau

Purpose

To present a guideline for quality control of the external radiotherapy treatment planning system (TPS) and treatment plans from the Spanish Society of Medical Physics. The document provides recommendations for each part of the process, from commissioning and periodic checks of the TPS to treatment planning processes and plan verifications.

Recommendations

The minimum necessary equipment required to carry out the recommended tasks is described. Subsequently, recommendations for the characterization and modelling of treatment units are presented, divided into beam data acquisition, configuration, and validation. Next, the document focuses on quality control of the TPS, outlining recommendations regarding the initial reference state, periodic checks, and software updates. This is followed by quality assurance of the treatment planning process, structured into three subsections: implementation of new techniques (end-to-end tests and audits), evaluation of treatment plans, and protocolization and class solutions. The final section contains recommendations about treatment plan verification, covering the commissioning and quality control of dedicated systems, as well as their recommended usage and the organization of treatment verifications. The document concludes with a table listing explicit tolerances for each process.

Conclusions

This guideline offers a novel framework for harmonizing the quality of radiotherapy treatment planning, with emphasis on end-to-end evaluations, modeling accuracy, process verification, and periodic stability assessments. These recommendations provide a clear direction for harmonizing current practices and are expected to enhance the reliability and safety of TPS calculations by reducing variability and promoting consistency and efficiency in treatment planning processes.

目的介绍西班牙医学物理学会放射治疗计划系统（TPS）和治疗方案的质量控制指南。该文件为过程的每个部分提供了建议，从TPS的调试和定期检查到处理计划过程和计划验证。建议描述了执行建议任务所需的最低必要设备。随后，提出了对处理单元的表征和建模的建议，分为光束数据采集，配置和验证。接下来，该文件重点介绍了TPS的质量控制，概述了关于初始参考状态、定期检查和软件更新的建议。接下来是治疗计划过程的质量保证，结构分为三个小节：新技术的实现（端到端测试和审核），治疗计划的评估，以及协议化和分类解决方案。最后一部分包含关于治疗计划验证的建议，包括专用系统的调试和质量控制，以及它们的推荐使用和治疗验证的组织。该文件最后附有一个表，列出了每种工艺的明确公差。本指南提供了一个新的框架来协调放疗治疗计划的质量，重点是端到端评估、建模准确性、过程验证和定期稳定性评估。这些建议为协调目前的做法提供了明确的方向，并有望通过减少可变性和促进治疗计划过程的一致性和效率来提高TPS计算的可靠性和安全性。

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引用次数: 0

Evaluation of the accuracy of an in vivo 3D dose reconstruction method using on-treatment EPID images 使用治疗中EPID图像评估体内3D剂量重建方法的准确性。

IF 2.7 3区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Physica Medica-European Journal of Medical Physics

Pub Date : 2026-01-01 DOI: 10.1016/j.ejmp.2025.105681

WenZhao Sun , HongDong Liu , SiJuan Huang , Xin Yang , MingMing Zhang , YongBao Li , XiaoYan Huang

Purpose

To validate a novel in vivo 3D dose reconstruction system through comprehensive comparisons with phantom measurements and TPS calculations.

Methods

Validation was performed using homogeneous and anthropomorphic phantoms across multiple techniques and sites. Point and 2D doses were compared against measurements (with ion chamber and EBT3 film) and TPS calculations in homogeneous phantom. 3D dose validation were conducted both in homogeneous and anthropomorphic phantoms via gamma analysis (2 %-5%/2–3 mm). Sensitivity to morphological, setup, and delivery errors was evaluated using anthropomorphic phantoms.

Results

The system demonstrated high dosimetric accuracy, with point dose differences between reconstructed, measured, and TPS-calculated values all within ± 1 %. Gamma passing rates (GPR) for planar dose comparisons exceeded 98 % (3 %/2 mm) and 94 % (2 %/2 mm). In 3D dose validation, GPR values exceeded 98 % in homogeneous phantoms and 97 % in anthropomorphic phantoms, even under the most stringent criterion (2 %/2 mm). For sensitivity and specificity, 3DCRT plans ranged from 1.00 and 0.75 (2 %/2 mm) to 1.00 and 1.00 (5 %/2 mm), while VMAT plans ranged from 1.00 and 1.00 (2 %/2 mm) to 0.667 and 1.00 (5 %/2 mm).

Conclusions

A novel 3D dose reconstruction algorithm was developed to determine on-treatment 3D dose distributions in patients using transit EPID images. The system demonstrated high consistency with both measured doses and TPS-calculated doses, indicating its suitability for clinical implementation.

目的：通过与幻影测量和TPS计算的综合比较，验证一种新的体内三维剂量重建系统。方法：在多个技术和地点使用同质和拟人化的模型进行验证。将点剂量和二维剂量与均匀模体中的测量值（使用离子室和EBT3膜）和TPS计算进行比较。通过伽马分析（2 %-5%/2-3 mm）对均匀和拟人模型进行三维剂量验证。对形态、设置和传递错误的敏感性使用拟人模型进行评估。结果：该系统具有较高的剂量学准确度，重建值、实测值和tps计算值之间的点剂量差均在 ± 1 %范围内。平面剂量比较的伽马通过率（GPR）超过98 %（3 %/ 2mm）和94 %（2 %/ 2mm）。在三维剂量验证中，即使在最严格的标准（2 %/ 2mm）下，均匀型幻影的GPR值超过98 %，拟人型幻影的GPR值超过97 %。对于敏感性和特异性，3DCRT计划范围为1.00和0.75（2 %/ 2mm）至1.00和1.00(5 %/ 2mm)， VMAT计划范围为1.00和1.00（2 %/ 2mm）至0.667和1.00（5 %/ 2mm）。结论：我们开发了一种新的三维剂量重建算法，利用传输EPID图像确定患者治疗时的三维剂量分布。该系统与测量剂量和tps计算剂量均表现出高度一致性，表明其适合临床实施。

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引用次数: 0

Medical physics at the intersection of technology, methodology, and clinical impact: highlights from the NACP Scientific Symposium 2023 医学物理学在技术，方法和临床影响的交叉点：从NACP科学研讨会2023的亮点。

IF 2.7 3区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Physica Medica-European Journal of Medical Physics

Pub Date : 2026-01-01 DOI: 10.1016/j.ejmp.2025.105710

Iuliana Toma-Dasu

引用次数: 0