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Purpose: A photon Monte Carlo (MC) model was commissioned for flattened (FF) and flattening filter free (FFF) 6 MV beam energy. The accuracy of this model, as a single model to be used for three beam matched LINACs, was evaluated.
Methods: Multiple models were created in RayStation v.10A for three linacs equipped with Elekta "Agility" collimator. A clinically commissioned collapsed cone (CC) algorithm (GoldCC), a MC model automatically created from the CC algorithm without further optimization (CCtoMC) and an optimized MC model (GoldMC) were compared with measurements. The validation of the model was performed by following the recommendations of IAEA TRS 430 and comprised of basic validation in a water tank, validation in a heterogeneous phantom and validation of complex IMRT/VMAT paradigms using gamma analysis of calculated and measured dose maps in a 2D-Array.
Results: Dose calculation with the GoldMC model resulted in a confidence level of 3% for point measurements in water tank and heterogeneous phantom for measurements performed in all three linacs. The same confidence level resulted for GoldCC model. Dose maps presented an agreement for all models on par to each other with γ criteria 2%/2mm.
Conclusions: The GoldMC model showed a good agreement with measured data and is determined to be accurate for clinical use for all three linacs in this study.
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http://dx.doi.org/10.1016/j.ejmp.2023.102588 | DOI Listing |
Cureus
August 2025
Neurosurgery-Gamma Knife Program, International Cancer Center, Diagnostic Hospital, San Salvador, SLV.
Stereotactic radiosurgery (SRS), a noninvasive technique that delivers a high dose of ionizing radiation to a precisely defined focal target volume, is foundational to modern neuro-oncology and functional neurosurgery. SRS provides highly accurate, noninvasive treatment for a range of intracranial conditions, including malignant and benign tumors, vascular malformations such as arteriovenous malformations (AVMs), and movement or functional disorders like trigeminal neuralgia. Despite a well-documented safety record and demonstrable efficacy, significant disparities in accessibility persist across global, geographic, and socioeconomic lines.
View Article and Find Full Text PDFJ Appl Clin Med Phys
September 2025
Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamilnadu, India.
Background And Purpose: Reducing the dose rate enhances efficacy in radiation therapy by allowing increased repair of sub-lethal damage. Pulsed low-dose radiation therapy (PLDR) is an innovative approach that is safe and effective for the reirradiation of recurrent gliomas and radioresistant tumors. In this study, the accuracy of the low dose rate volumetric modulated arc therapy (VMAT) delivery is tested in an Elekta Versa HD linear accelerator (linac) for delivering PLDR.
View Article and Find Full Text PDFCancers (Basel)
August 2025
Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
Background: Stereotactic body radiation therapy (SBRT) has proven effective in controlling spinal lesions with minimal toxicity, primarily due to its ability to limit spinal cord dose. Recent advances in MR-linac (MRL) technology offer superior spinal cord visualization and real-time gating, which can facilitate dose escalation in spinal tumor treatment while maintaining safety.
Purpose: This study aimed to optimize motion management for spine SBRT on an MRL by analyzing patient-specific motion dynamics and evaluating the most effective registration structures.
Cureus
July 2025
Department of Neuroendocrinology, National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez", Mexico City, MEX.
Background and objective Fractionated stereotactic radiotherapy (FSRT) and stereotactic radiosurgery (SRS) are commonly used in patients with growth hormone (GH)-secreting pituitary adenomas (PAs) who are not candidates for surgery, have residual disease postoperatively, or have failed or cannot access medical therapy. It is also considered a first-line option in elderly patients or those with comorbidities that contraindicate surgery. In this study, we aimed to evaluate the long-term outcomes of SRS and FSRT in patients with acromegaly who remained biochemically active despite prior surgical and/or medical treatment.
View Article and Find Full Text PDFMed Phys
September 2025
Radiation Oncology, Department of Medical and Surgical Sciences (DIMEC), Alma Mater Studiorum, University of Bologna, Bologna, Italy.
Background: Patient-specific quality assurance (PSQA) is essential to guarantee the requested accuracy and safety of high-precision radiotherapy treatments. With the widespread adoption of modulated-intensity techniques, there is a growing need for increased operational efficiency. The potential of machine learning (ML) to accurately predict PSQA results has been investigated in recent years.
View Article and Find Full Text PDF