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Background: Neurosurgical cranial titanium mesh and screws are commonly encountered in postoperative radiation therapy. However, only a limited number of reports are available in the context of proton therapy, resulting in a lack of consensus among the proton centers regarding the protocol for handling the hardware.
Purpose: This study is to examine the impact of the hardware in proton plans. The results serve as evidence for proton centers to generate standard operating procedures to manage the hardware in proton treatment.
Methods: Plans with different gantry angles and material overrides are generated on the CT images of a phantom made of the hardware. The dose distributions of the plans with and without material override, at different depths are compared. Films and ionization chambers are used to measure the plans and the measurements are compared to the treatment planning system (TPS) calculations by gamma analysis.
Results: There are some overdose and underdose regions downstream of the hardware. The overdose and underdose values are within a few percent of the prescribed dose when multiple fields with large hinge angles are used. The gamma analysis results show that the measurements agree with the TPS calculations within limits that are clinically relevant.
Conclusion: The study has demonstrated the influence of the hardware on proton plans. Based on the result of this study, a standard operating procedure of managing the hardware has been implemented in our clinic.
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http://dx.doi.org/10.1002/acm2.14374 | DOI Listing |
Front Oncol
August 2025
Department of Spinal Surgery, No. 1 Orthopedics Hospital of Chengdu, Chengdu, China.
Primary bone tumours remain among the most challenging indications in radiation oncology-not because of anatomical size or distribution, but because curative intent demands ablative dosing alongside stringent normal-tissue preservation. Over the past decade, the therapeutic landscape has shifted markedly. Proton and carbon-ion centres now report durable local control with acceptable late toxicity in unresectable sarcomas.
View Article and Find Full Text PDFPhys Med Biol
August 2025
Departments of Biomedical Engineering and Radiology, University of California, Davis, CA, United States of America.
. Monte Carlo (MC) simulation remains the gold standard for modeling complex physical interactions in transmission and emission tomography, with graphic processing unit (GPU) parallel computing offering unmatched computational performance and enabling practical, large-scale MC applications. In recent years, rapid advancements in both GPU technologies and tomography techniques have been observed.
View Article and Find Full Text PDFCureus
July 2025
Miami Neuroscience Center, Larkin Community Hospital, Miami, USA.
Gyroscopic stereotactic radiosurgery (SRS) systems, such as ZAP-X, enable precise, isocentric beam delivery with high conformality and minimal exposure to surrounding tissues. While standard quality assurance (QA) protocols verify beam centricity and overall targeting accuracy, they are not specifically designed to assess the consistency of beam entry angles, which can vary in systems employing gimbaled delivery. These angular variations, though often less consequential at the target, may have significant dosimetric implications for peripheral critical structures.
View Article and Find Full Text PDFMagn Reson Med
August 2025
Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong SAR, China.
Purpose: Recent studies have shown that spin-lock MRI can simplify quantitative magnetization transfer (MT) by eliminating its dependency on water pool parameters, removing the need for a T1 map in macromolecular proton fraction (MPF) quantification. However, its application is often limited by the requirement for long radiofrequency (RF) pulse durations, which are constrained by RF hardware capabilities despite remaining within specific absorption rate (SAR) safety limits.
Methods: To address this challenge, we propose a novel method, MPF mapping using pulsed spin-lock (MPF-PSL).
Anal Chim Acta
October 2025
Nantes Université, CNRS, CEISAM, UMR6230, F-44000, Nantes, France.
Background: Quantitative NMR analysis of complex samples may involve the suppression of multiple signals. The WET (Water suppression Enhanced through T effects) sequence is currently used, but it is known to be less efficient when using high field spectrometers and/or cryoprobes. Saturation based methods have been proposed to circumvent this problem.
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