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Objective: This study aims to analyze setup errors in pelvic Volumetric Modulated Arc Therapy (VMAT) for patients with non-surgical primary cervical cancer, utilizing the onboard iterative kV cone beam CT (iCBCT) imaging system on the Varian Halcyon 2.0 ring gantry structure accelerator to enhance radiotherapy precision.
Method: We selected 132 cervical cancer patients who underwent VMAT with daily iCBCT imaging guidance. Before each treatment session, a registration method based on the bony structure was employed to acquire iCBCT images with the corresponding planning CT images. Following verification and adjustment of image registration results along the three axes (but not rotational), setup errors in the lateral (X-axis), longitudinal (Y-axis), and vertical (Z-axis) directions were recorded for each patient. Subsequently, we analyzed 3642 iCBCT image setup errors.
Results: The mean setup errors for the X, Y, and Z axes were 4.50 ± 3.79 mm, 6.08 ± 6.30 mm, and 1.48 ± 2.23 mm, respectively. Before correction with iCBCT, setup margins based on the Van Herk formula for the X, Y, and Z axes were 6.28, 12.52, and 3.26 mm, respectively. In individuals aged 60 years and older, setup errors in the X and Y axes were significantly larger than those in the younger group (p < 0.05). Additionally, there is no significant linear correlation between setup errors and treatment fraction numbers.
Conclusion: Data analysis underscores the importance of precise Y-axis setup for cervical cancer patients undergoing VMAT. Radiotherapy centers without daily iCBCT should appropriately extend the planning target volume (PTV) along the Y-axis for cervical cancer patients receiving pelvic VMAT. Elderly patients exhibit significantly larger setup errors compared to younger counterparts. In conclusion, iCBCT-guided radiotherapy is recommended for cervical cancer patients undergoing VMAT to improve setup precision.
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http://dx.doi.org/10.1002/acm2.14480 | DOI Listing |
Med Phys
September 2025
Department of Accelerator and Medical Physics, National Institutes for Quantum Science and Technology (QST), Chiba, Japan.
Background: Multi-ion radiotherapy using carbon, oxygen, and neon ions aims to improve local control by increasing dose-averaged linear energy transfer (LET) in the target. However, there has been limited understanding of how to utilize variables for multi-ion treatment planning such as the selection and arrangement of ion species.
Purpose: An in silico study was conducted to explore the feasibility of increasing a minimum LET, and the optimal selection and arrangement of ion species in multi-ion therapy for increasing LET in tumors of varying sizes mimicking bone and soft tissue sarcomas (BSTS).
Anal Chim Acta
November 2025
Institute of Nano Science and Technology, Knowledge City, Sahibzada Ajit Singh Nagar, Sector- 81, Punjab, 140306, India. Electronic address:
Background: Iron (Fe) is an essential micronutrient for plant growth, but the conventional DTPA soil analysis method for detecting available iron has notable limitations, requiring advanced instruments and lengthy preparation time. Developing a more affordable, user-friendly, and efficient method for iron detection in soil could greatly improve crop nutrition management. Here, a facile nanoscopic method was developed to quantify available Fe ions in the soil by forming a luminescence quenching complex in chelation with bathophenanthroline disulphonic acid disodium salt (Fe/BPDS complex).
View Article and Find Full Text PDFInt J Comput Assist Radiol Surg
September 2025
Department of Rhythmology, University Heart Center Lübeck, University Hospital Schleswig-Holstein, Ratzeburger Allee 160, Lübeck, 23652, Germany.
Purpose: Ultrasound (US) is commonly used to assess left ventricular motion for examination of heart function. In stereotactic arrhythmia radioablation (STAR) therapy, managing cardiorespiratory motion during radiation delivery requires representation of motion information in computed tomography (CT) coordinates. Similar to conventional US-guided navigation during surgical procedures, 3D US can provide real-time motion data of the radiation target that could be transferred to CT coordinates and then be accounted for by the radiation system.
View Article and Find Full Text PDFTech Innov Patient Support Radiat Oncol
September 2025
Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada.
Background: Tattoos help guide field placement in breast re-irradiation. This study evaluates the stability of medial tattoos in patients with prior breast radiotherapy (RT) to determine their reliability as surface markers.
Materials And Methods: We retrospectively identified patients who had breast/chest wall re-irradiation between January 2022 and December 2023 (RT) and prior breast RT (RT) at our institution.
Rev Sci Instrum
September 2025
National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
In this work, we developed a vacuum-compatible long trace profiler (LTP) for in situ metrology of ultra-precise x-ray optics within synchrotron vacuum chambers. Although traditional LTPs operate ex situ under atmospheric pressure, earlier optical setups-such as that by Qian et al.-performed in situ distortion measurements by directing laser beams through vacuum viewports.
View Article and Find Full Text PDF