Journal of Medical Physics最新文献

{"title":"Evaluation of Condylar Space Measurements before and after Prosthetic Rehabilitation in a Defined Cohort using Cone-beam Computed Tomography: A Prospective, Preliminary, Interventional Study.","authors":"K V Athira, K Nanda Kumar, R P Shanoj, John Francis, P Faseela, A S Manasa, J Suresh Babu, C Swarnalatha, Abhishek Singh Nayyar","doi":"10.4103/jmp.jmp_82_26","DOIUrl":"10.4103/jmp.jmp_82_26","url":null,"abstract":"<p><strong>Background and aim: </strong>The temporomandibular joints (TMJs) play a crucial role in maintaining functional harmony of the stomatognathic system. Loss of natural dentition and the resulting alteration in mandibular positioning can lead to imbalances in the TMJs, contributing to temporomandibular disorders. The present study aimed to assess the relationship between posterior edentulousness and condylar space measurements before and after prosthetic rehabilitation in a defined cohort using cone-beam computed tomography.</p><p><strong>Materials and methods: </strong>A prospective, preliminary, interventional study was conducted on 20 edentulous subjects, aged 50-65 years, presenting with complete edentulism in the maxilla and Kennedy's Class I edentulism in the mandible, while the spatial relationship of the condyles within TMJs was assessed pre- and post-rehabilitation, and the results obtained were statistically analyzed.</p><p><strong>Results: </strong>The findings of the present study indicated that prosthetic intervention did not carry a significant impact on the anterior and superior joint spaces on the right side, while it led to a significant increase in the posterior joint space on the right side (<i>P</i> = 0.023). Conversely, on the left side, prosthetic intervention led to a significant increase in both the superior (<i>P</i> = 0.018) and posterior (<i>P</i> = 0.005) joint spaces, while the anterior joint space remained unaffected.</p><p><strong>Conclusions: </strong>The results revealed that prosthetic intervention led to notable changes in the condylar positioning, emphasizing the critical interrelationship between occlusion and TMJ dynamics. The study supports the concept that comprehensive prosthodontic care should not only aim to restore function and esthetics but also consider the biomechanical impact it carries on the health of the TMJs.</p>","PeriodicalId":51719,"journal":{"name":"Journal of Medical Physics","volume":"51 3","pages":"688-696"},"PeriodicalIF":1.1,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13675044/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149217274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fictive Field-based Feathering for Extended-SSD Total Body Irradiation: A Single-institution Planning and Dosimetric Analysis.","authors":"Vijay Kumar Mogulagani, Mohan Raj Uthiran, Ben Johnson Varghese, Siva Kumar Radhakrishnan, Lakshmana Perumal, Madhuri Dumpala","doi":"10.4103/jmp.jmp_87_26","DOIUrl":"10.4103/jmp.jmp_87_26","url":null,"abstract":"<p><strong>Purpose: </strong>The purpose of this study was to describe the planning, dosimetric evaluation, quality assurance (QA), and clinical implementation of a feathered junction technique for low-dose total body irradiation (TBI) using a common coordinate system and fictive field approach with an extended source-to-skin distance (SSD) anteroposterior/posteroanterior (AP/PA) couch-based linear accelerator technique.</p><p><strong>Materials and methods: </strong>Six patients treated with low-dose TBI for hematopoietic stem cell transplant conditioning were included. Two patients had aplastic anemia (2 Gy/1 fraction), two had myelodysplastic syndrome (4 Gy/2 fractions), and two had leukemia (2 Gy/1 fraction). Computed tomography (CT) simulation was performed in head-first supine and feet-first supine positions using a full-body Vac-Lok system, with a pelvic fiducial marker defining a common coordinate origin. Treatment planning was performed in the Monaco treatment planning system for an Elekta Synergy linear accelerator (6 MV, MLCi2). An extended-SSD AP/PA technique with jaw-based feathered junctions was used. Dosimetric evaluation included target coverage, junction dose characteristics, and organ-at-risk doses. QA included ionization chamber measurements and cone-beam CT verification.</p><p><strong>Results: </strong>Adequate target coverage was achieved. The mean planning target volume D95% and V95% were 92.9% ±2.05% and 94.03% ±1.47%, respectively. The mean maximum dose was 115.51% ±0.32%, mainly in peripheral regions. The mean lung doses were 103% ±1.2% and 104% ±0.8%, and kidney doses were 102% ±0.96% and 101.5% ±1.35%. Junction doses ranged from 102.5% ±0.5% to 105.5% ±0.6%.</p><p><strong>Conclusion: </strong>The technique achieved acceptable dose homogeneity and controlled junction doses. It provides a reproducible and feasible approach for low-dose TBI using standard linear accelerator infrastructure without organ shielding.</p>","PeriodicalId":51719,"journal":{"name":"Journal of Medical Physics","volume":"51 3","pages":"525-535"},"PeriodicalIF":1.1,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13675045/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149217278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FLUKA Monte Carlo-based Evaluation of Linear Energy Transfer Distributions for Monoenergetic Therapeutic Carbon-ion Beams in Water.","authors":"Arghya Chattaraj, T Palani Selvam, Vandana Shrivastava","doi":"10.4103/jmp.jmp_140_26","DOIUrl":"10.4103/jmp.jmp_140_26","url":null,"abstract":"<p><strong>Background: </strong>This study aims to calculate the distribution of linear energy transfer (<i>LET</i>) and its moments such as fluence-averaged <i>LET</i> (<i>LET</i> _<i>f</i> ) and dose-averaged <i>LET</i> (<i>LET</i> _<i>d</i> ) as a function of on-axis depth in water for monoenergetic carbon-ion beams with energies ranging from 80 to 480 MeV/u.</p><p><strong>Materials and methods: </strong>Depth-dose profiles, <i>LET</i> distributions, <i>LET</i> _<i>f</i> , and <i>LET</i> _<i>d</i> are calculated as a function of on-axis depth in a 40 cm × 40 cm × 40 cm unit-density liquid water phantom using the FLUKA Monte Carlo code, fully incorporating the contributions of primary ions and all secondary charged fragments.</p><p><strong>Results: </strong>Results show that both <i>LET</i> _<i>f</i> and <i>LET</i> _<i>d</i> increase with depth and reach a maximum near the Bragg peak region, followed by a rapid fall-off in the distal region as the fluence of heavy ion fragments decreases. Higher beam energies result in deeper <i>LET</i> peaks and more pronounced fragmentation tails in the depth-dose profiles. In the Bragg peak region, depending on beam energy, the <i>LET</i> _<i>f</i> and <i>LET</i> _<i>d</i> values are in the range of 11.7-106.4 keV/mm and 210.7-384.6 keV/mm, respectively.</p><p><strong>Conclusion: </strong>Overall, the results provide a comprehensive characterization of physical and radiobiological parameters for monoenergetic carbon-ion beams in the therapeutic energy range, essential for benchmarking <i>LET</i>-based RBE models, improving treatment plan robustness, and optimizing biological dose delivery in carbon-ion radiotherapy.</p>","PeriodicalId":51719,"journal":{"name":"Journal of Medical Physics","volume":"51 3","pages":"513-524"},"PeriodicalIF":1.1,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13675053/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149217297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Helium-Free Magnetic Resonance Imaging: Transforming Magnetic Resonance Imaging through Sustainable Magnet Technology.","authors":"Arnabjyoti Deva Sarma","doi":"10.4103/jmp.jmp_133_26","DOIUrl":"10.4103/jmp.jmp_133_26","url":null,"abstract":"<p><p>Magnetic resonance imaging (MRI) remains one of the most powerful diagnostic tools in medicine; however, its dependence on liquid helium for superconducting magnet cooling poses substantial economic, environmental, and logistical challenges. The global helium shortage and rising operational costs have accelerated the pursuit of sustainable alternatives that can maintain high diagnostic performance while reducing ecological impact. A systematic literature review was conducted using PubMed, Scopus, ScienceDirect, and Google Scholar databases, covering studies published between 2018 and 2025. The analysis focused on innovations in helium-free and cryogen-minimized MRI systems, including cryocooler-based conduction cooling, high-temperature superconductors (HTS), permanent and resistive magnet technologies, and the integration of artificial intelligence (AI) and digital twin frameworks for performance optimization. Findings indicate that helium-free MRI technologies deliver comparable image quality, field stability, and clinical utility to conventional systems while offering significant reductions in helium dependency, power consumption, and maintenance costs. Cryocooler and HTS-based magnets enable higher operational efficiency and reliability, while portable low-field permanent magnet systems enhance accessibility in low-resource settings. Moreover, AI-driven image reconstruction and predictive maintenance via digital twins improve workflow efficiency and sustainability. Helium-free MRI represents a paradigm shift toward sustainable and equitable medical imaging. By combining advanced magnet technologies, intelligent optimization systems, and eco-efficient design, these next-generation scanners address the global helium crisis and environmental footprint of healthcare infrastructure, redefining MRI as a cornerstone of green radiology.</p>","PeriodicalId":51719,"journal":{"name":"Journal of Medical Physics","volume":"51 3","pages":"462-474"},"PeriodicalIF":1.1,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13675052/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149217272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiorgan Segmentation in Magnetic Resonance Images for Gynecological Brachytherapy Using Residuals in Residual Dense Block.","authors":"Suresh Das, Prasun Sanki, Siladittya Manna, Subhayan Mondal, Saumik Bhattacharya, Sayantari Ghosh","doi":"10.4103/jmp.jmp_35_26","DOIUrl":"10.4103/jmp.jmp_35_26","url":null,"abstract":"<p><strong>Background: </strong>Deep learning has significantly improved medical image segmentation, particularly in complex applications such as gynecological brachytherapy (BT). This study proposes a novel U-Net variant, the residual in residual dense block U-Net (RU-Net), to address the segmentation of organs-at-risk (OARs), which are often distorted due to BT probe insertion. Accurate segmentation is essential for effective treatment planning; however, task-specific datasets are scarce. To tackle this, a dedicated magnetic resonance imaging (MRI) dataset was developed, focusing on the precise delineation of OARs.</p><p><strong>Methods: </strong>The RU-Net architecture enhances feature extraction through embedded residual in residual dence block (RRDB) modules. It was trained and evaluated using a multiplanar (axial, coronal, and sagittal) MRI dataset. The study benchmarks RU-Net against pyramid scene parsing network, residual U-Net, U-Net++, and traditional U-Net models. Performance was assessed using categorical cross-entropy and dice loss metrics.</p><p><strong>Results: </strong>Under the dice loss function, RU-Net consistently outperformed competing models across all anatomical planes. It achieved superior scores in accuracy, precision, recall, and intersection over union (IOU), particularly excelling in class-wise IOUs for critical structures such as bladder, rectum, sigmoid colon, and femoral heads.</p><p><strong>Discussion: </strong>The architecture improved both boundary delineation and overall prediction quality. It is established that the proposed RU-Net shows its supremacy under dice loss conditions in terms of proper prediction and segmentation.</p><p><strong>Conclusion: </strong>RU-Net offers a robust solution for multiorgan segmentation in gynecological BT. Its advanced design effectively addresses anatomical distortions, demonstrating strong potential to improve clinical outcomes in magnetic resonance-guided treatment planning.</p>","PeriodicalId":51719,"journal":{"name":"Journal of Medical Physics","volume":"51 3","pages":"578-590"},"PeriodicalIF":1.1,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13675018/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149217347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Dosimetric Evaluation of Tomotherapy with a 1-cm Field Width versus Volumetric-modulated Arc Therapy for Whole-brain Radiotherapy with Hippocampal Avoidance.","authors":"Sankar Sekar, R Leel Malar, A Dinesh Babu, Ezhil Sindhanai M Parvath, Muthiah Kasi, M Sai Pranav, Saravana Kumar Adhimoolam","doi":"10.4103/jmp.jmp_128_26","DOIUrl":"10.4103/jmp.jmp_128_26","url":null,"abstract":"<p><strong>Background: </strong>Hippocampal-avoidance whole-brain radiotherapy (HA-WBRT) reduces radiation dose to the hippocampal neural stem-cell niche, helping preserve neurocognitive function in patients with brain metastases.</p><p><strong>Objective: </strong>The objective of this study is to compare tomotherapy using a 1-cm field width with four-arc volumetric-modulated arc therapy (VMAT) for HA-WBRT.</p><p><strong>Materials and methods: </strong>Twenty patients prescribed 30 Gy in 10 fractions were planned on both platforms. Hippocampi were contoured on T1-weighted magnetic resonance imaging according to the RTOG 0933 atlas. Tomotherapy plans used a 1-cm jaw, pitch 0.500, and modulation factor 1.5-2.0, while VMAT plans used 6 MV photons with one coplanar and three noncoplanar arcs. Plan quality, hippocampal and organ-at-risk (OAR) doses, treatment efficiency, and deliverability (3%/3 mm gamma analysis) were compared.</p><p><strong>Results: </strong>Planning target volume coverage was comparable (V95%: 96.67% ± 0.57% vs. 96.53% ± 0.73%; <i>P</i> = 0.28). Tomotherapy achieved superior homogeneity and conformity (both <i>P</i> < 0.001), with significantly lower hippocampal Dmax, Dmean, D40%, V10 Gy, and bilateral lens and globe doses (all <i>P</i> < 0.001). Gamma pass rates exceeded 95% for both techniques. VMAT provided shorter beam-on time (2.62 ± 0.25 vs. 12.21 ± 0.99 min) and lower monitor units (MU) (786.5 ± 74.9 vs. 12440.5 ± 992.9; both <i>P</i> < 0.001).</p><p><strong>Conclusion: </strong>Tomotherapy with a 1-cm field width provides superior hippocampal sparing, plan quality, and OAR protection while maintaining equivalent target coverage. VMAT achieves substantially faster treatment delivery with fewer MU, offering an alternative when shorter treatment times are preferred.</p>","PeriodicalId":51719,"journal":{"name":"Journal of Medical Physics","volume":"51 3","pages":"603-609"},"PeriodicalIF":1.1,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13675046/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149217280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dosimetric and Treatment Delivery Efficiency Comparison of Two Ring-gantry Linear Accelerator Platforms for Liver Stereotactic Body Radiotherapy.","authors":"Srikanth Guduru, Rohith Singareddy, N V N Madhusudhana Sresty, Deleep Kumar Gudipudi, Aparna Dode","doi":"10.4103/jmp.jmp_91_26","DOIUrl":"10.4103/jmp.jmp_91_26","url":null,"abstract":"<p><strong>Purpose: </strong>The purpose of this study was to compare the dosimetric performance and treatment delivery efficiency of two ring-gantry linear accelerator platforms, Helical Tomotherapy and Halcyon, in stereotactic body radiation therapy (SBRT) for liver metastasis.</p><p><strong>Materials and methods: </strong>A retrospective dosimetric analysis was conducted on 16 patients with solitary liver metastasis. For each patient, SBRT plans were generated using the Accuray treatment planning system (TPS) (Tomotherapy) and Eclipse TPS (Halcyon). Plan evaluation included conformity, homogeneity, and gradient indices, along with target coverage and organs at risk (OAR) dose-volume parameters, in accordance with Radiation Therapy Oncology Group-1112 (RTOG-1112) guidelines. Treatment efficiency was assessed using monitor units (MU) and beam-on time (BOT). Statistical analysis was performed using paired <i>t</i>-tests (SPSS v28.0), with <i>P</i> < 0.05 considered statistically significant.</p><p><strong>Results: </strong>Both platforms achieved acceptable target coverage and OAR constraints. Conformity index and gradient index were comparable. Halcyon showed improved planning target volume homogeneity, lower normal liver V15 Gy, reduced OAR doses, and significantly lower MU and BOT (<i>P</i> < 0.05), indicating superior treatment efficiency.</p><p><strong>Conclusion: </strong>Both Tomotherapy and Halcyon are capable of generating high-quality liver SBRT plans with comparable target coverage. However, Halcyon demonstrated improved normal tissue sparing and enhanced treatment efficiency.</p>","PeriodicalId":51719,"journal":{"name":"Journal of Medical Physics","volume":"51 3","pages":"697-704"},"PeriodicalIF":1.1,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13675051/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149217332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface-guided Radiation Therapy in Clinical Practice: A Review with Perspectives on Implementation in Resource-constrained Settings.","authors":"Ezhil Sindhanai M Parvath, Muthiah Kasi, M Sai Pranav, Anjali Thiruthiyil, Sankar Sekar, Leel Malar, Dinesh Babu","doi":"10.4103/jmp.jmp_125_26","DOIUrl":"10.4103/jmp.jmp_125_26","url":null,"abstract":"<p><p>Surface-guided radiation therapy (SGRT) has emerged as a nonionizing image guidance modality that uses optical surface reconstruction for patient positioning, intra-fraction motion monitoring, and respiratory motion management. Although clinical adoption has expanded in high-income settings over the past decade, the technology remains underutilized in low- and middle-income countries where the global cancer burden is concentrated. This review synthesizes current evidence on SGRT technology, commercial platforms, clinical applications, quality assurance (QA), and workflow considerations, with emphasis on practical implementation in resource-constrained settings. The established role of SGRT in breast deep inspiration breath-hold monitoring, its emerging applications in palliative and cranial treatments, integration within hybrid image-guidance workflows, and role in online adaptive radiotherapy are discussed. Commercial platforms including AlignRT, C-RAD Catalyst/Sentinel, IDENTIFY, and the hybrid surface-thermal-X-ray ExacTrac Dynamic system are compared. QA recommendations based on American Association of Physicists in Medicine TG-302 and European Society for Radiotherapy and Oncology-Advisory Committee on Radiation Oncology Practice guidelines are summarised. Under-discussed limitations, including region-of-interest selection variability, body habitus and skin pigmentation effects on surface detection (where evidence remains limited), and over-reliance on surface surrogates for deep-seated targets are critically evaluated. Emerging low-cost alternatives, particularly smartphone-based Light detection and ranging surface tracking, are discussed as a potential pathway toward more equitable surface guidance in radiation oncology.</p>","PeriodicalId":51719,"journal":{"name":"Journal of Medical Physics","volume":"51 3","pages":"475-485"},"PeriodicalIF":1.1,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13675024/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149217344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CoFe₂O₄ Nanoparticles: Synthesis, Physicochemical Characterization, and Reactive Oxygen Species-mediated Selective Cytotoxicity for Radiotherapy Applications.","authors":"Ananda Jadhav, Sandeep B Wategoankar, Vaishali R Shinde, Sarita Patil","doi":"10.4103/jmp.jmp_83_26","DOIUrl":"10.4103/jmp.jmp_83_26","url":null,"abstract":"<p><p>Magnetic spinel ferrite nanoparticles with redox-active surface characteristics have attracted increasing attention as candidate nanomaterials for enhancing radiation-mediated therapeutic response. This study involved the creation of CoFe₂O₄ nanoparticles through a precisely managed chemical co-precipitation approach, followed by thermal annealing to obtain structurally stable inverse spinel nanostructures. The formation of a phase-pure cubic spinel lattice was confirmed by X-ray diffraction and Raman spectroscopy, whereas electron microscopy revealed predominantly spherical nanoparticles with sizes in the range of 20-40 nm. Nitrogen adsorption-desorption analysis demonstrated mesoporous surface characteristics with specific surface area values between 42 and 73 m²/g, supporting enhanced nanoparticle-cell interaction. The incorporation of redox-active Co²⁺ and Fe³⁺ species into the spinel lattice was validated by X-ray photoelectron spectroscopy. Biological assessments utilizing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay indicated concentration-dependent cytotoxicity against MCF-7 breast cancer lines; however, normal L929 fibroblasts retained comparatively higher viability, suggesting targeted action. The observed cytotoxic behavior is attributed to reactive oxygen species-mediated mitochondrial dysfunction induced by transition-metal-dependent redox activity. In addition, antioxidant activity measured using 2,2 diphenyl-1-picrylhydrazyl assay confirmed concentration-dependent radical scavenging behavior, supporting the redox-modulating capability of the synthesized nanoparticles. The combined structural stability, mesoporous surface architecture, and ROS-mediated selective cytotoxic response suggest that CoFe₂O₄ nanoparticles may serve as promising ferrite-based candidate nanomaterials for nanoparticle-assisted radiotherapy applications. These findings support further investigation of mixed-metal ferrite nanoparticles as potential radiosensitizing agents under clinically relevant fractionated radiation dose conditions.</p>","PeriodicalId":51719,"journal":{"name":"Journal of Medical Physics","volume":"51 3","pages":"536-545"},"PeriodicalIF":1.1,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13675049/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149217156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dosimetric Comparison of Functional Radiosurgery Treatments for Trigeminal Neuralgia, Essential Tremor, and Obsessive-compulsive Disorder Using Gamma Knife, CyberKnife, and Linear Accelerators.","authors":"Carlos Daniel Venencia, Crystian Wilian Chagas Saraiva, Gabriela Reis Dos Santos de Jesus","doi":"10.4103/jmp.jmp_17_26","DOIUrl":"10.4103/jmp.jmp_17_26","url":null,"abstract":"<p><strong>Purpose: </strong>This study aims to evaluate and compare dose distribution for a trigeminal neuralgia (TN), essential tremor (ET), and obsessive-compulsive disorder (OCD) plan, using Gamma Knife (GK) Perfexion, CyberKnife (CK), and linear accelerators (linac) for a single treatment case.</p><p><strong>Materials and methods: </strong>For all treatment platforms, plans utilized the same isocenter position and anatomical structures, with GK Perfexion plans as the reference. The prescribed doses were established at 90 Gy for TN, 140 Gy for ET, and 120 Gy for OCD. The irradiation geometry for each platform was defined to optimize the dose gradient vector in all directions. Dose distributions were evaluated both qualitatively and quantitatively. Dose profiles were extracted from axial and coronal plans to assess and compare the full width at half maximum (FWHM) and the penumbra size. Doses to normal tissue were compared, and the gradient index (GI) was used to evaluate the dose fall-off.</p><p><strong>Results: </strong>Dose distribution from CK and linac closely imitated GK Perfexion. The maximum difference for FWHM and penumbra was 2.1 mm and 1.3 mm, respectively, for the TN plans, with linac producing steeper dose gradients than GK Perfexion. The GI, in turn, was significantly different for the CK ET plan, with a value of 5.4 compared to 3.8 for GK Perfexion and linac. This difference did not have a clinical impact, as the dose to normal tissue was within tolerance.</p><p><strong>Conclusions: </strong>All platforms provided appropriate dose distribution and dose constraints.</p>","PeriodicalId":51719,"journal":{"name":"Journal of Medical Physics","volume":"51 3","pages":"591-602"},"PeriodicalIF":1.1,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13675048/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149217353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}