Zeitschrift fur Medizinische Physik医学物理杂志
Zeitschrift fur Medizinische Physik(英文缩写 Z MED PHYS),ISSN 0939-3889,eISSN 1876-4436,中文译名:医学物理杂志 是一本学术期刊。本页汇总该期刊的最新影响因子、分区信息以及最新收录于 PubMed 的文献,帮助您快速了解期刊全貌。
发文量统计区间：2025-11-01 至 2026-10-31，按本站收录文献的发表日期统计。
期刊介绍
历年影响因子趋势
| JCR 数据年份 | 影响因子 | JCR 分区 |
|---|---|---|
| 2021 | 7.215 | Q1 |
| 2022 | 2.000 | Q3 |
| 2023 | 2.400 | Q2 |
| 2024 | 4.200 | Q1 |
| 2025 | 4.700 | Q1 |
Zeitschrift fur Medizinische Physik 最新收录文献
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1. {"_":"Single-time-point renal TIA estimation, sparse SPECT/CT data, and nonlinear mixed-effects modelling in [Lu]Lu-PSMA-617 therapy.","sup":["177"]}
PMID:日期:2026-09-15This study evaluates the feasibility of Single-Time-Point (STP) renal Time-Integrated Activity (TIA) estimation using Population-Based Model Selection (PBMS) and Nonlinear Mixed-Effects Modelling (NLMEM) with sparse time-activity data in [Lu]Lu-PSMA-617 therapy. Kidney biokinetics of [1Lu]Lu-PSMA-617 from 64 metastatic castration-resistant prostate cancer (mCRPC) patients were collected at TP1=(4.8±0.9h)(n=62),TP2=(24.5±1.5 h)(n=6),TP3=(94.0±6.6h)(n=16),and TP4=(128.5±12.7h)(n=47) post-injection with 1-4 data per patient. Six sum-of-exponentials functions (4-7 adjustable parameters) were fitted to all-time-point (ATP) data using NLMEM, evaluating combinations of fixed effects, inter-individual, and residual variability. The best-supported PBMS-NLMEM model was used to derive the ATP-based internal comparator TIA. Agreement between STP-derived TIAs and ATP-based internal comparator TIAs was quantified using relative deviation (RD), mean absolute percentage error (MAPE), and root-mean-square error (RMSE). Based on PBMS-NLMEM analysis, function [Formula: see text] with a fixed-effect value of λ=7.19×10/h, residual variability of 0.079, and inter-individual variabilities of A=0.38 and λ=0.52 assigned from the literature was selected as the best function for TIA estimation. STP TIA estimation with NLMEM showed better agreement than Hänscheid's method across all investigated TPs. Moreover, NLMEM-based STP estimation was technically feasible at each TP, with maximum RMSE and MAPE values of 25.2% and 16.5%, respectively. However, findings should be interpreted cautiously because patient subsets differed across TPs, particularly at TP2(n=6). In this retrospective sparse-data cohort, PBMS-NLMEM-based STP renal TIA estimation was technically feasible at the investigated TPs and showed agreement with an ATP-based internal comparator, with MAPE below 16.5%. Prospective validation in balanced cohorts is required before recommending a specific STP imaging window or clinical implementation.
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2. Magnetic resonance elastography of brain tumors.
PMID:日期:2026-08-28Magnetic resonance elastography (MRE) is a non-invasive imaging technique that can be used to quantify the mechanical properties of brain tissue. Mechanical changes in brain tissue cannot be directly assessed with conventional imaging, whereas MRE provides viscoelastic maps that reveal stiffness differences between healthy brain tissue and benign and malignant tumors. Studies in healthy individuals have demonstrated regional differences in mechanical properties between gray and white matter. Similar variability is observed in brain tumors, where mechanical properties differ with tumor type, grade, histological subtype, and microstructural composition. MRE has been applied to benign brain tumors, including meningiomas, vestibular schwannomas, and pituitary adenomas, to evaluate tumor consistency and support surgical planning. In malignant tumors like glioblastoma, stiffness differences have been linked to changes in extracellular matrix, including fibrous composition, adhesion molecules, and vascular remodeling. As suggested by preclinical research, MRE may also detect treatment-induced mechanical changes and could potentially be used to longitudinally monitor alterations in the tumor microenvironment. This review summarizes current knowledge of MRE in brain tumors, with a focus on stiffness and viscosity related parameters and their biological and structural correlates. The literature reviewed here increasingly supports reduced tissue fluidity and increased mechanical heterogeneity as biomechanical hallmarks of brain tumor aggressiveness.
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3. Modeling and optimization of a multiple-ring double scattering system for proton therapy.
PMID:日期:2026-08-17This study investigates proton beam scattering systems with the aim of improving beam-shaping efficiency and increasing transmission within the radiation field for low-energy beams under intensity-limited conditions. These improvements are particularly relevant for delivering radiation fields at high dose rates for ocular proton therapy (OPT) and even at ultra-high dose rates for potential FLASH radiotherapy applications. A systematic methodology was developed to design multiple-ring double-scattering systems that maximize transmission under a field-homogeneity constraint while controlling the outgoing kinetic energy after each ring. Although generally applicable, the framework was specifically motivated by clinical and experimental requirements for proton-based ocular therapy using a 70 MeV cyclotron at the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB). A Python-based graphical user interface (GUI) was implemented to integrate a mathematical optimization model for two to four concentric rings that maximizes transmission under homogeneity constraints. The software incorporates energy degradation, range shifting, and the conversion of optimized scattering angles into physical dimensions. The mathematical optimization accurately reproduced the two-ring results reported by Takada (1994) and extended the approach to three- and four-ring configurations. The four-ring system achieved a transmission of 53±2% with a dose homogeneity of ±3%, corresponding to a dose rate of 77Gy/s at 100nA for a 30 mm field size, exceeding the threshold for FLASH conditions. Bragg-peak measurements and Monte Carlo simulations using TOPAS showed a distal penumbra below 1 mm and a water range agreement within 0.1 mm of predictions, supporting the adopted energy degradation methodology. The developed GUI provides a practical tool for designing and refining double-scattering systems, significantly improving transmission compared with single-scattering approaches. The four-ring design increased beam transmission more than tenfold compared with single scattering, making it a promising candidate for high-dose-rate irradiation in small fields.
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4. Swiss survey and national diagnostic reference levels for PET/CT examinations in adults.
PMID:日期:2026-08-07Diagnostic Reference Levels (DRLs) are benchmarks for optimizing radiation doses in medical imaging. This study establishes new national DRLs (NDRLs) for PET/CT examinations in Switzerland based on a multicentre survey. Administered activities for PET examinations and dose indicators for localization / attenuation correction (AC) CT scans were collected in Swiss nuclear medicine (NM) institutes between April and September 2025. Data from 45 PET devices in 35 NM institutes were analysed (100% response). New NDRLs were defined as administered activitiesfor nine PET examinations: general oncology with [F]FDG (3.1 MBq/kg; 220 MBq), prostate cancer imaging with [F]F-PSMA (3.1 MBq/kg; 260 MBq), neuroendocrine tumour imaging with [Ga]Ga-DOTA (2.1 MBq/kg; 160 MBq), brain tumour imaging with [F]FET (3.0 MBq/kg; 200 MBq), inflammation/infection with [F]FDG (3.3 MBq/kg; 230 MBq), neurological examinations with [F]FDG (2.9 MBq/kg; 200 MBq) and [F]flutemetamol (2.8 MBq/kg; 185 MBq), parathyroid imaging with [F]fluorocholine (2.8 MBq/kg; 200 MBq), and myocardial perfusion with [Rb]rubidium chloride (8.6 MBq/kg; 630 MBq/injection). Updated volume computed tomography dose index (CTDI) and dose-length product (DLP) for four AC CT were defined for vertex to mid-thighs (3.8 mGy/410 mGy·cm), vertex to feet (3.8 mGy/680 mGy·cm), brain (6.1 mGy/150 mGy·cm) and cardiac scans (1.3 mGy/40 mGy·cm). CTDI for AC CT varied considerably among NM institutes (1.0 - 7.5 mGy for vertex to mid-thighs), indicating potential for protocol optimization and standardization. The established NDRLs tended to be lower than international reference levels, and the corresponding dosimetric indices were generally low. The survey provides an overview of administered activities and CT doses in adult PET/CT examinations in Switzerland and establishes new NDRLs to guide protocol optimization.
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6. Performance evaluation of the Biograph Trinion EP2 PET/CT system according to NEMA NU2-2018.
PMID:日期:2026-08-04This study evaluates the performance of the Siemens Biograph Trinion EP2 whole-body PET/CT system according to the NEMA NU2-2018 standard. Following the NEMA NU2-2018 standard, spatial resolution was measured using a Na point source in air, sensitivity was calculated from consecutive measurements of a F containing line source surrounded by aluminum tubes, count rate performance, accuracy of corrections assessment and TOF resolution was based on measurements of an F line-source inside scatter phantom. PET-CT co-registration accuracy was assessed by radioactive and radiation dense point sources, image quality was evaluated using a NEMA IQ phantom. Measurements were done using implemented NEMA NU2-2018 acquisition protocols on a Siemens Biograph Trinion EP2 PET/CT system. The Trinion EP2 showed a spatial resolution between 4.0 and 4.4 mm FWHM at the center of the FOV. Sensitivity was measured with 13.8 kBq/MBq and the peak noise equivalent count rage of 143 kcps measured at 14.8 kBq/mL with a corresponding scatter fraction of 37.5%. The maximum average error was 1.6% between 1 kBq/mL and 14.8 kBq/mL and a TOF resolution of 241 ps was measured at a clinical activity concentration. Contrast recoveries between 47.2% and 81.6% were measured in the image quality phantom when using standard reconstructions. The Biograph Trinion EP2 PET/CT system shows a good overall performance providing a decent image quality comparable to state-of-the-art PET/CT systems with standard axial FOV between 20 and 30 cm.
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7. A vergence-based calculation framework for optimal rotational adjustment of toric supplementary intraocular lenses to minimise residual refractive cylinder.
PMID:日期:2026-07-31To present a transparent, physics-based, and generalisable calculation framework to predict the optimal rotational adjustment of toric supplementary intraocular lenses (SIOLs), comprising toric phakic intraocular lenses implanted in the phakic eye and toric AddOn (secondary sulcus-fixated) lenses implanted in the pseudophakic eye, quantifying the expected refractive benefit across four corneal models. A paraxial vergence-based calculation framework was implemented to predict the optimal toric axis of a misaligned SIOL. Required inputs were the measured manifest refraction at spectacle plane, corneal power (using either thin- or thick-cornea models), labelled equivalent and toric power of the SIOL, measured SIOL axis, and axial SIOL position. The effective lens position was estimated by combining the measured back-vertex position with an offset between the back-vertex plane and the image-sided principal plane, derived from legacy phakic lens design data or custom template SIOL models. Forward and backward spherocylindrical vergence transformations were embedded in a nonlinear sequential quadratic programming optimisation to identify the SIOL axis that minimised residual refractive cylinder. The method was demonstrated in four representative clinical scenarios, including phakic, pseudophakic , keratoplasty, and prior laser vision correction eyes. In all examples, the model predicted a specific rotational adjustment of the SIOL (16-18°) that substantially reduced refractive cylinder. Absolute reductions ranged from 1.7 to 2.4 D, corresponding to relative cylinder reductions of 67-94%. The framework successfully accommodated different corneal models and lens types, and provided predicted postoperative refraction and quantitative performance metrics. This framework enables individualised planning of toric SIOL realignment across diverse corneal models and lens geometries. Explicitly defining optical assumptions and vergence transformations allows reproducible prediction of both optimal rotation and expected refractive benefit using routine clinical inputs. Prospective clinical validation is warranted.
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8. Influence of additional PMMA on the calibration of X-ray multimeters for mammography radiation qualities.
PMID:日期:2026-07-18X-ray multimeters (XMMs) are widely used for quality control measurements in mammography, providing air kerma, half-value layer (HVL), and tube voltage from a single exposure. The energy dependence of their response was comprehensively investigated for various anode/filter combinations and software selections. However, the influence of a change in the X-ray spectrum due to additional material in the beam has not yet been systematically investigated. The aim of this study is to quantify the sensitivity of XMM calibration coefficients to changes in X-ray spectra introduced by additional polymethyl methacrylate (PMMA) of different thicknesses. Four commercially available XMMs were calibrated at the IAEA dosimetry laboratory for air kerma, HVL, and tube voltage using two anode/filter combinations (Mo/Mo and W/Al) at tube voltages ranging from 25kV to 35kV. Calibration coefficients were determined without additional filtration and with PMMA thicknesses of 2.0mm, 2.8mm, and 4.8mm placed close to the X-ray tube to modify the primary spectrum while minimizing scattered radiation reaching the detectors. In relation to the calibration coefficient determined without PMMA deviations of up to 11% were observed for air kerma rate. HVL and tube voltage calibration coefficients exhibited substantially larger deviations, reaching up to 37% and 42%, respectively. We conclude that changes in the X-ray spectra as from additional PMMA filtration, can substantially alter XMM calibration coefficients, particularly for HVL and tube voltage measurements. XMM responses are highly sensitive to spectral modifications beyond standard anode/filter combinations and tube voltage settings.
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9. CBCT dose reduction with HyperSight on an Ethos linear accelerator: A phantom-based TLD measurement study.
PMID:日期:2026-07-16The novel HyperSight cone-beam CT (CBCT) system (Varian Medical Systems, Siemens Healthineers, Palo Alto, USA) provides image quality comparable to native CT and offers advantages for contouring in online-adaptive radiotherapy. However, daily imaging increases organ dose. This study evaluates and compares organ doses across HyperSight protocols on an O-ring Linac and calculates the effective dose and secondary cancer risk associated with daily imaging. Thermoluminescent dosimeter (TLD) measurements were performed on an anthropomorphic phantom for all pre-configured CBCT protocols in HyperSight, with TLDs placed according to each entity (head, head and neck, thorax, chest, and pelvis). The resulting imaging doses were compared across the various protocols and TLD positions, followed by the calculation of effective doses and the associated secondary cancer risk. HyperSight CBCT demonstrated lower organ doses compared with previous systems. Mean bladder and rectum dose was 10mGy versus 27mGy for OBI Version 1.4.13, while mean head dose was 2mGy compared with 1.2mGy for Halcyon 3.0. A left-right dose asymmetry was observed due to partial gantry rotation, resulting in higher exposure in beam-facing organs. Imaging dose varied considerably between protocols. Low Dose protocols reduced exposure by up to 55%, whereas slow and large protocols increased dose by 40-60%. HyperSight provides high-quality imaging with lower dose levels than previous CBCT generations. The observed beam geometry-related asymmetry should be considered in clinical use, and individualized protocol selection is essential to minimize unnecessary exposure in image guided and adaptive radiotherapy under ALARA principles.
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10. Toward clinical harmonization of radiobiological modeling in particle-based radiotherapy: a translational review of proton, heavy-ion, and BNCT frameworks.
10. 迈向粒子放射治疗中放射生物学建模的临床协调：质子、重离子和BNCT框架的翻译综述PMID:日期:2026-07-14[中文摘要] 基于粒子的放射治疗，包括质子治疗、重离子治疗和硼中子俘获治疗（BNCT），能够实现适形剂量投照，但引入了依赖于模型的生物剂量不确定性。这种不确定性反映了相对生物效应（RBE）、线性能量转移（LET）、氧合状态、微剂量学能谱和硼分布等方面的差异，因此相同的名义处方可能不会产生等效的生物学效应。本综述总结了具有代表性的临床模型、二次综述模型和研究性模型家族，包括固定RBE和可变RBE质子模型、用于重离子的局部效应模型（LEM）和微剂量动力学模型（MKM）家族，以及化合物生物效应（CBE）、光子等效应剂量、微剂量学和纳米剂量学BNCT框架。我们比较了这些模型的假设、输入描述符、验证状态、临床就绪度和实施障碍。我们进一步区分了嵌入处方的临床系统与二次综述模型及研究性机制框架，以阐明目前支持各模型家族的临床证据水平。已发表的实验和模型比较研究表明，质子RBE在高LET远端边缘区域可能升高；基于LEM和MKM的碳离子系统可在RBE加权剂量解读中产生具有临床相关性、依赖于部位和终点的差异；BNCT生物剂量受组分剂量和硼分布假设的强烈影响。我们提出一个基于证据的四层协调视角，而非正式共识指南，包括最低报告要求、参考映射、模型敏感性质量保证（QA）和基于登记系统的临床学习。
[英文摘要] Particle-based radiotherapy, including proton therapy, heavy-ion therapy, and boron neutron capture therapy (BNCT), enables conformal dose delivery but introduces model-dependent biological-dose uncertainty. This uncertainty reflects variations in relative biological effectiveness (RBE), linear energy transfer (LET), oxygenation, microdosimetric spectra, and boron distribution, so identical nominal prescriptions may not yield equivalent biological effects. This review summarizes representative clinical, secondary-review, and investigational model families, including fixed and variable-RBE proton models, the local effect model (LEM) and microdosimetric kinetic model (MKM) families for heavy ions, and compound biological effectiveness (CBE), photon-isoeffective-dose, microdosimetric, and nanodosimetric BNCT frameworks. We compare their assumptions, input descriptors, validation status, clinical readiness, and implementation barriers. We further distinguish prescription-embedded clinical systems from secondary-review models and investigational mechanistic frameworks to clarify the current level of clinical evidence supporting each model family. Published experimental and model-comparison studies indicate that proton RBE may increase in high-LET distal-edge regions, that LEM- and MKM-based carbon-ion systems can yield clinically relevant, site- and endpoint-dependent differences in RBE-weighted dose interpretation, and that BNCT biological dose is strongly affected by component-dose and boron-distribution assumptions. We propose an evidence-informed four-layer harmonization perspective, rather than a formal consensus guideline, consisting of minimum reporting, reference mapping, model-sensitivity quality assurance (QA), and registry-based clinical learning.