In recent years, the use of the Electronic Portal Imaging Device (EPID) as an in vivo dosimeter has become widespread. However, reports of EPID for stereotactic body radiotherapy (SBRT) applications is scarce. There is no data on this topic especially when there are high-density materials in the radiation field. In this study, we aimed to investigate the dose distributions of SBRT treatment plans in patients with spinal implants by transit EPID dosimetry. Implants were inserted in phantoms that mimic the vertebrae, and VMAT plans were created on the phantoms to deliver 16 Gy radiation doses to the target in 1 fraction. Transit EPID measurements were performed for each irradiation. The results were compared with the treatment planning system using the gamma analysis method. According to the gamma analysis results, while the non-implant model met the acceptance criteria with a rate of 95.4%, the implanted models did not pass the test with results between the rates of 70% to 73%. In addition, while the dose difference in the isocenter was 1.3% for the non-implanted model, this difference was observed to be between 7 and 8% in the implanted models. Our study revealed that EPID can be used as transit dosimetry for the VMAT-SBRT applications. However, unacceptable dose differences were obtained by transit EPID dosimetry in the VMAT-SBRT applications of patients with an implant. In the treatment of such patients, alternative treatment methods should be preferred in which the interaction of the implants with radiation can be prevented.
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http://dx.doi.org/10.1007/s13246-022-01177-5 | DOI Listing |
BMC Public Health
January 2025
National Institute for Health Research (NIHR) School for Public Health Research (SPHR), Newcastle, UK.
Background: In England, 23% of children aged 11 start their teenage years living with obesity. An adolescent living with obesity is five times more likely to live with obesity in adult life. There is limited research and policy incorporating adolescents' views on how they experience the commercial determinants of dietary behaviour and obesity, which misses an opportunity to improve services and policies that aim to influence the prevalence of childhood obesity.
View Article and Find Full Text PDFGlobal Health
December 2024
European Centre for Environment & Human Health, University of Exeter Medical School, Penryn, UK.
Background: Caribbean populations face complex health issues related to diet and food security as they undergo a rapid nutrition transition, resulting in some of the world's highest number of premature deaths from noncommunicable diseases (NCDs). Despite policy efforts to promote local and regional food consumption, reliance on food imports remains high with many Caribbean countries importing more than 80% of their food from larger economies. Previous regional research revealed the importance of food sharing practices in the Caribbean, with implications for the consumption of local foods, food security, and community resilience against climate change.
View Article and Find Full Text PDFMed Phys
November 2024
Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California, USA.
Background: The electronic portal imaging device (EPID) can be used in vivo, to detect on-treatment errors by evaluating radiation exiting a patient. To detect deviations from the planning intent, image predictions need to be modeled based on the patient's anatomy and plan information. To date in vivo transit images have been predicted using Monte Carlo (MC) algorithms.
View Article and Find Full Text PDFRadiother Oncol
December 2024
Servei de Radiofísica i Radioprotecció, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.
Background And Purpose: Transit-Guided Radiation Therapy (TGRT) is a novel technique that uses the transit portal images (TPIs) acquired with Electronic Portal Image Devices (EPID) to quantify patient position errors during the treatment. It has been validated using anthropomorphic phantoms but a validation in a clinical setting was lacking. A pilot clinical study is presented to confirm our previous results.
View Article and Find Full Text PDFRep Pract Oncol Radiother
February 2024
Department Physics, Faculty of Mathematics and Natural Sciences Universitas Indonesia, Depok, Indonesia.
Background: This study compared the effectiveness of five deep learning models in constructing non-transit dosimetry with an a-Si electronic portal imaging device (EPID) on Varian Halcyon. Deep learning model is increasingly used to support prediction and decision-making in several fields including oncology and radiotherapy.
Materials And Methods: Forty-seven unique plans of data obtained from breast cancer patients were calculated using Eclipse treatment planning system (TPS) and extracted from DICOM format as the ground truth.
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