Real-time Radiation Research Articles

Room staff radiation dose in a vascular surgery hybrid operating room and evaluation of a real-time radiation dosimeter

Abstract Objective Real-time radiation dosimeter have been shown to decrease radiation exposure of the staff. This effect is mainly explained by increased awareness of the radiation due to direct radiation exposure feedback to the operator. We aimed to measure the radiation exposure of all staff members working in a hybrid operating room and wanted to compare the equivalent doses of real-time radiation dosimeters with thermoluminescence dosimeters. Methods Prospective non-randomized comparative trial. From April – October 2019, all staff members working in a hybrid operating room were equipped with real-time radiation dosimeters (Unfors RaySafe i3). The table positions of all staff members were documented. In addition, the first operator was equipped with a thermoluminescence Hp(3) eye lens dosimeter (TLD) placed outside the lead glasses to validate the real-time radiation dosimeter. Results The median dose of the operator / the first assistant was 73.6 µSv / 21.8 µSv for EVAR (n = 30); 57.25 µSv / 18.2 µSv for TEVAR (n = 23); 207.0 µSv / 76.65 µSv for more complex aortic procedures (f/bEVAR etc.; n = 15); 14.85 µSv / 8.5 µSv for occlusive disease of the iliac arteries (n = 27) and 6.1 µSv / 3.4 µSv for occlusive disease of the peripheral arteries (n = 53). The anesthesiologist’s median dose was 0.3 µSv, with highest values in f/bEVAR (3.9µSv). The scrub nurse’s median dose was 2 µSv with highest values in f/bEVAR (24 µSv). The position of any staff member at the left arm for transbrachial cannulation in f/bEVAR was associated with higher median equivalent radiation doses compared to the right femoral position (272.5 vs. 207 µSv for the operator (p=ns), 175.3 vs. 27.8 µSv for the first assistant (p = 0.027) and 45.55 vs. 8.0 µSv for the scrub nurse (p = 0.14)). The equivalent doses of the TLD and RaySafe did not correlate well using simple lineal regression analysis (r2 0.1713, p = 0.0014). Conclusion With the RaySafe real-time radiation dosimeter, table positions with increased radiation exposure can be identified. This allows for improvement in shielding at these positions, possibly leading to lower radiation exposure of the staff.

Evaluating the Need For An Analytical Model of Correlated mm-Wave Channels of 5G For Mobility-Related Scenarios

Communication with the millimeter-wave (mm-Wave) is one of the new features present in the fifth generation (5G) mobile networks. The possibility and challenges related to a large population have encouraged many study-based studies to evaluate proposed solutions. Communication in millimeter waves is one of the following Great innovations of the 5G mobile network. For a big reason: Available bandwidth value. However, a millimeter-wave channel given the nature of harsh distribution and sensitivity to congestion. Therefore, the correct modeling of mm-Wave channels is the basis for obtaining accurate results in the simulation of the mm-Wave mobile system. The quality of the mm-wave simulation depends on the channel model, but the favorite channel models of millimeter waves such as the spatial channel model (SCM) have advanced computer density and reduce the density of the solution. End-to-end, systematic development and research. This paper gives an informative exercise in the mm-Wave full-grown section included in ns-3 open source testing system. The module incorporates a variety of models as well as the ability to combine real-time measurements or radiation tracking data. This paper provides equal distribution of a few measurements, for example, SINR in very big cases. We also provide pieces of information on the use of cases where using an easy model can produce the official outcome.

Radiation Risk Assessment on Public in Motijheel Thana, Dhaka, Bangladesh

Objective: The pollution free environment is required for healthy life. The real-time radiation monitoring is very important for radiation hazard detection in the environment. The excess life-time cancer risk (ELCR) on public is to assess based on the real-time radiation monitoring data in the area. Methods: The real-time radiation monitoring was performed using portable digital radiation monitoring device. This real-time digital portable radiation monitoring device meets all European CE standards as well as the American “FCC 15 standard”. The real-time digital portable radiation monitoring device was placed at 1 meter above the ground on tripod and data collection time for each monitoring point (MP) was 1 hour. 27 MPs were chosen for collection of real-time radiation data at various outdoor environment in Motijheel Thana, Dhaka from May-August 2018.Results: The real-time radiation dose rates at Motijheel Thana due to natural radionuclides were ranged from 0.095 ± 0.041 µSv.h-1 to 0.185 ± 0.042 µSv.h-1 with an average of 0.147 ± 0.047 µSv.h-1. The annual effective dose to public from outdoor environmental radiation at Motijheel Thana were found to be 0.166 ± 0.066 mSv to 0.324 ± 0.061 mSv with an average of 0.257 ± 0.039 mSv. Excess Life-time Cancer Risk (ELCR) on public are also estimated based on annual effective dose that is ranged from 0.662 ×10-3 to 1.289 ×10-3 with an average value of 1.025 ×10-3, which is higher than world average value of 0.29×10-3. Conclusion: This type of study is required for detection of the radiation hazard arising from the natu-ral as well as man-made sources and also for generation of the baseline database. From this study, it is observed that there is no pose any radiation hazard in the study area due to man-made sources.

Radiation Risk Assessment on Public in Motijheel Thana, Dhaka, Bangladesh

Objective: The pollution free environment is required for healthy life. The real-time radiation monitoring is very important for radiation hazard detection in the environment. The excess life-time cancer risk (ELCR) on public is to assess based on the real-time radiation monitoring data in the area. Methods: The real-time radiation monitoring was performed using portable digital radiation monitoring device. This real-time digital portable radiation monitoring device meets all European CE standards as well as the American “FCC 15 standard”. The real-time digital portable radiation monitoring device was placed at 1 meter above the ground on tripod and data collection time for each monitoring point (MP) was 1 hour. 27 MPs were chosen for collection of real-time radiation data at various outdoor environment in Motijheel Thana, Dhaka from May-August 2018.Results: The real-time radiation dose rates at Motijheel Thana due to natural radionuclides were ranged from 0.095 ± 0.041 µSv.h-1 to 0.185 ± 0.042 µSv.h-1 with an average of 0.147 ± 0.047 µSv.h-1. The annual effective dose to public from outdoor environmental radiation at Motijheel Thana were found to be 0.166 ± 0.066 mSv to 0.324 ± 0.061 mSv with an average of 0.257 ± 0.039 mSv. Excess Life-time Cancer Risk (ELCR) on public are also estimated based on annual effective dose that is ranged from 0.662 ×10-3 to 1.289 ×10-3 with an average value of 1.025 ×10-3, which is higher than world average value of 0.29×10-3. Conclusion: This type of study is required for detection of the radiation hazard arising from the natu-ral as well as man-made sources and also for generation of the baseline database. From this study, it is observed that there is no pose any radiation hazard in the study area due to man-made sources.

Characterization of YAG:Ce phosphor dosimeter by the co-precipitation method for radiotherapy.

Yttrium aluminum garnet (YAG) doped with Ce was synthesized via the co-precipitation method with NH4HCO3 as the precipitant. The spectroscopic properties and the effects of the Ce doping concentration and sintering atmosphere on the crystal phase were investigated. The dosimeter of YAG:Ce phosphor material was prepared to study the radioluminescence (RL) characteristics of a clinical linear accelerator. A satisfying linear relationship between the radiation dose and RL signal was obtained, which provided a reference for the YAG:Ce phosphor material used in radiotherapy and real-time remote radiation detection.

Initial evaluation of the temperature dependence of novel inorganic optical fibre dosimeters

In recent years, there has been a growing interest in developing optical fiber-based dosimetry systems for real-time verification during radiation therapy. Inorganic scintillation detectors (ISDs) show promise for in-vivo dosimetry, along with plastic scintillation detectors (PSDs), providing real-time radiation monitoring, electromagnetic field immunity, linear responses to doses and dose rate independency [1,2].

Estimation of Radiation Risk on Public Around Shaheed Suhrawardy Medical College Hospital Campus, Dhaka, Bangladesh

Objective: Ionizing radiation is widely used in the hospital for diagnostic and therapeutic procedures to patients and its usage increasing day by day. The aim of the study is to monitor the real-time radiation around the Shaheed Suhrawardy Medical College (ShSMC) hospital campus and estimation of radiation risk on public.
 Method: The real-time radiation monitoring around the ShSMC hospital was performed using digital portable radiation monitoring device (DPRMD). The DPRMD meets all European CE standards and the American “FCC 15 standard”. The DPRMD was placed at 1 meter above the ground on tripod and data collection time for each monitoring point (MP) was 1 hour. Each MP was marked out using Garmin eTrex GPS device. 32 MPs were chosen for collection of the real-time radiation dose rates around the ShSMC hospital campus in October 2020.
 Results: The real-time radiation dose rates around the ShSMC hospital campus were ranged from 0.37-3.39 µSv/hr with an average of 1.537 ± 0.359 µSv/hr. The annual effective dose on public were ranged from 1.326 ± 0.551 mSv to 4.902 ± 0.705 mSv with an average of 2.694 ± 0.629 mSv. The excess life-time cancer risk (ELCR) on public health was estimated based on the annual effective dose that ranged from 5.277×10ˆ-3 to 19.503×10ˆ-3 with an average value of 10.72×10ˆ-3 around the ShSMC hospital campus.
 Conclusion: Real-time radiation monitoring facilitates to ensure the safety of the radiation workers and the public from undue radiation hazard. The study also gives instant information of improper operation of radiation generating equipments and improper handling of radioactive substances in the hospital.

Estimation of Radiation Risk on Public Around Shaheed Suhrawardy Medical College Hospital Campus, Dhaka, Bangladesh

Objective: Ionizing radiation is widely used in the hospital for diagnostic and therapeutic procedures to patients and its usage increasing day by day. The aim of the study is to monitor the real-time radiation around the Shaheed Suhrawardy Medical College (ShSMC) hospital campus and estimation of radiation risk on public.
 Method: The real-time radiation monitoring around the ShSMC hospital was performed using digital portable radiation monitoring device (DPRMD). The DPRMD meets all European CE standards and the American “FCC 15 standard”. The DPRMD was placed at 1 meter above the ground on tripod and data collection time for each monitoring point (MP) was 1 hour. Each MP was marked out using Garmin eTrex GPS device. 32 MPs were chosen for collection of the real-time radiation dose rates around the ShSMC hospital campus in October 2020.
 Results: The real-time radiation dose rates around the ShSMC hospital campus were ranged from 0.37-3.39 µSv/hr with an average of 1.537 ± 0.359 µSv/hr. The annual effective dose on public were ranged from 1.326 ± 0.551 mSv to 4.902 ± 0.705 mSv with an average of 2.694 ± 0.629 mSv. The excess life-time cancer risk (ELCR) on public health was estimated based on the annual effective dose that ranged from 5.277×10ˆ-3 to 19.503×10ˆ-3 with an average value of 10.72×10ˆ-3 around the ShSMC hospital campus.
 Conclusion: Real-time radiation monitoring facilitates to ensure the safety of the radiation workers and the public from undue radiation hazard. The study also gives instant information of improper operation of radiation generating equipments and improper handling of radioactive substances in the hospital.

Gastrointestinal 4D MRI with respiratory motion correction.

Gastrointestinal motion patterns such as peristalsis and segmental contractions can alter the shape and position of the stomach and intestines with respect to other irradiated organs during radiation therapy. Unfortunately, these deformations are concealed by conventional four-dimensional (4D)-MRI techniques, which were developed to visualize respiratory motion by binning acquired data into respiratory motion states without considering the phases of GI motion. We present a method to reconstruct breathing-compensated images showing the phases of periodic gastric motion and study the effect of this motion on regional anatomical structures. Sixty-seven DCE-MRI examinations were performed on patients undergoing MRI simulation for hepatocellular carcinoma using a golden-angle stack-of-stars sequence that collected 2000 radial spokes over 5min. The collected data were reconstructed using a method with integrated respiratory motion correction into a time series of 3D image volumes without visible breathing motion. From this series, a gastric motion signal was extracted by temporal filtering of time-intensity curves in the stomach. Using this motion signal, breathing-corrected back-projection images were sorted according to the gastric phase and reconstructed into 21 gastric motion state images showing the phases of gastric motion. Reconstructed image volumes showed gastric motion states clearly with no visible breathing motion or related artifacts. The mean frequency of the gastric motion signal was 3cycles/min with a standard deviation of 0.27cycles/min. Periodic gastrointestinal motion can be visualized without confounding respiratory motion using the presented GI 4D MRI technique. GI 4D MRIs may help define internal target volumes for treatment planning, aid in planning organ at risk volume definition, or support motion model development for gastrointestinal motion tracking algorithms for real-time MR-guided radiation therapy.

Technical Challenges of Real-Time Adaptive MR-Guided Radiotherapy.

In the past few years, radiotherapy (RT) has experienced a major technological innovation with the development of hybrid machines combining magnetic resonance (MR) imaging and linear accelerators. This new technology for MR-guided cancer treatment has the potential to revolutionize the field of adaptive RT due to the opportunity to provide high-resolution, real-time MR imaging before and during treatment application. However, from a technical point of view, several challenges remain which need to be tackled to ensure safe and robust real-time adaptive MR-guided RT delivery. In this manuscript, several technical challenges to MR-guided RT are discussed. Starting with magnetic field strength tradeoffs, the potential and limitations for purely MR-based RT workflows are discussed. Furthermore, the current status of real-time 3D MR imaging and its potential for real-time RT are summarized. Finally, the potential of quantitative MR imaging for future biological RT adaptation is highlighted.

A rapid coupling method for calculating the radiation field in decommissioning nuclear power plants

The decommissioning of nuclear facilities in nuclear power plants require a rapid dose estimated method. In the past, dose estimation methods include the deterministic and stochastic methods, which have some defects that polarize the computation overhead or accuracy. To address this, we proposed the Monte Carlo–point kernel (MC-PK) coupling method. This paper establishes a nuclear power plant model and uses the nuclear reactor's available power operation history to calculate device source data. For comparison, the radiation field has been calculated using both the Monte Carlo method and the MC-PK coupling method. The comparison result demonstrates that the MC-PK coupling method's calculation time is much less than that for the Monte Carlo method and the mean absolute percentage error of MC-PK relative to MCM is 24.92%. This study provides a viable strategy for the real-time radiation field calculation of decommissioning nuclear facilities.

HARDWARE AND SOFTWARE COMPLEX FOR MEASURING HARD X-RAY RADIATION ON THE TORSATRON “URAGAN-2M”

This paper presents an automated measuring system for radiation monitoring and measurement of hard X-ray radiation in real time on the "Uragan-2M" torsatron. The system includes an ionizing radiation detector based on a scintillator and a photomultiplier tube, equipment for preliminary processing and normalization of detector signals, and a microcontroller unit for control, measurement and processing.

Microstructure Evolution of Ag/TiO2 Thin Film

Ag/TiO2 thin films were prepared using the sol-gel spin coating method. The microstructural growth behaviors of the prepared Ag/TiO2 thin films were elucidated using real-time synchrotron radiation imaging, its structure was determined using grazing incidence X-ray diffraction (GIXRD), its morphology was imaged using the field emission scanning electron microscopy (FESEM), and its surface topography was examined using the atomic force microscope (AFM) in contact mode. The cubical shape was detected and identified as Ag, while the anatase, TiO2 thin film resembled a porous ring-like structure. It was found that each ring that coalesced and formed channels occurred at a low annealing temperature of 280 °C. The energy dispersive X-ray (EDX) result revealed a small amount of Ag presence in the Ag/TiO2 thin films. From the in-situ synchrotron radiation imaging, it was observed that as the annealing time increased, the growth of Ag/TiO2 also increased in terms of area and the number of junctions. The growth rate of Ag/TiO2 at 600 s was 47.26 µm2/s, and after 1200 s it decreased to 11.50 µm2/s and 11.55 µm2/s at 1800 s. Prolonged annealing will further decrease the growth rate to 5.94 µm2/s, 4.12 µm2/s and 4.86 µm2/s at 2400 s, 3000 s and 3600 s, respectively.

Safety and effectiveness of strategies to reduce radiation exposure to proceduralists performing cardiac catheterization procedures: a systematic review.

The objective of this systematic review was to synthesize the best available evidence on the effect of various radiation protection strategies on radiation dose received by proceduralists performing cardiac catheterization procedures involving fluoroscopy. Cardiac catheterization procedures under fluoroscopy are the gold standard diagnostic and treatment method for patients with coronary artery disease. The growing demand of procedures means that proceduralists are being exposed to increasing amounts of radiation, resulting in an increased risk of deterministic and stochastic effects. Standard protective strategies and equipment such as lead garments reduce radiation exposure; however, the evidence surrounding additional equipment is contradictory. Randomized controlled trials that compared the use of an additional radiation protection strategy with conventional radiation protection methods were considered for inclusion. The primary outcome of interest was the radiation dose received by the proceduralist during cardiac catheterization procedures. A three-step search was conducted in MEDLINE, CINAHL, Embase, and the Cochrane Library (CENTRAL). Trials published in the English language with adult participants were included. Trials published from database inception until July 2019 were eligible for inclusion. The methodological quality of the included studies was assessed using the JBI critical appraisal checklist for randomized controlled trials. Quantitative data were extracted from the included papers using the JBI data extraction tool. Results that could not be pooled in meta-analysis were reported in a narrative form. Fifteen randomized controlled trials were included in the review. Six radiation protection strategies were assessed: leaded and unleaded pelvic or arm drapes, transradial protection board, remotely controlled mechanical contrast injector, extension tubing for contrast injection, real-time radiation monitor, and a reduction in frame rate to 7.5 frames per second. Pooled data from two trials demonstrated a statistically significant decrease in the mean radiation dose (P < 0.00001) received by proceduralists performing transfemoral cardiac catheterization on patients who received a leaded pelvic drape compared to standard protection. One trial that compared the use of unleaded pelvic drapes placed on patients compared to standard protection reported a statistically significant decrease (P = 0.004) in the mean radiation dose received by proceduralists.Compared to standard protection, two trials that used unleaded arm drapes for patients, one trial that used a remotely controlled mechanical contrast injector, and one trial that used a transradial protection board demonstrated a statistically significant reduction in the radiation dose received by proceduralists.Similarly, using a frame rate of 7.5 versus 15 frames per second and monitoring radiation dose in real-time radiation significantly lowered the radiation dose received by the proceduralist. One trial demonstrated no statistically significant difference in proceduralist radiation dose among those who used the extension tubing compared to standard protection (P = 1). This review provides evidence to support the use of leaded pelvic drapes for patients as an additional radiation protection strategy for proceduralists performing transradial or transfemoral cardiac catheterization. Further studies on the effectiveness of using a lower fluoroscopy frame rate, real-time radiation monitor, and transradial protection board are needed.

Improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise Deep Residual Model for Near Real-Time Short-Term Multi-Step Solar Radiation Prediction

Improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise Deep Residual Model for Near Real-Time Short-Term Multi-Step Solar Radiation Prediction

Characterization of optically-stimulated luminescence properties by NaCl:Eu2+ crystal and the thermal response

In this paper, we report optically-stimulated luminescence (OSL) properties of Eu2+-doped NaCl single crystal as a candidate phosphor for use in near real-time radiation measurement and dosimetry. The crystal was grown by the vertical Bridgman–Stockbarger method. The obtained crystal shows a strong photoluminescence (PL) band peaking at 430 nm due to the parity-allowed 5d-4f transitions of Eu2+. After irradiating with X-rays, it demonstrates OSL also at 430 nm due to the Eu2+ ion acting as an emission center while stimulating by light (500 ± 30 nm). Compared with a commercial BaFBr:Eu2+ OSL detector, the sensitivity to X-ray dose is lower by about one order of magnitude. In addition, while the crystal is reused multiple times, the OSL response signal increases despite the same given radiation dose. The OSL decay curve can be decomposed into three exponential decay functions with the lifetimes of 0.6, 6.4, and 120.5 s, and the decomposition analyses revealed that only the intensity of intermediate component increases with the number of reused cycles. Further analyses with thermally-stimulated luminescence (TSL) revealed that the intermediate OSL component is related to a TSL glow signal originated from trapping centers having the activation energies of ~0.93 eV and ~1.27 eV and the frequency factors of ~7.52 × 108 s−1 and ~6.29 × 1011 s−1, respectively.

MRI-guided Radiation Therapy: An Emerging Paradigm in Adaptive Radiation Oncology.

Radiation therapy (RT) continues to be one of the mainstays of cancer treatment. Considerable efforts have been recently devoted to integrating MRI into clinical RT planning and monitoring. This integration, known as MRI-guided RT, has been motivated by the superior soft-tissue contrast, organ motion visualization, and ability to monitor tumor and tissue physiologic changes provided by MRI compared with CT. Offline MRI is already used for treatment planning at many institutions. Furthermore, MRI-guided linear accelerator systems, allowing use of MRI during treatment, enable improved adaptation to anatomic changes between RT fractions compared with CT guidance. Efforts are underway to develop real-time MRI-guided intrafraction adaptive RT of tumors affected by motion and MRI-derived biomarkers to monitor treatment response and potentially adapt treatment to physiologic changes. These developments in MRI guidance provide the basis for a paradigm change in treatment planning, monitoring, and adaptation. Key challenges to advancing MRI-guided RT include real-time volumetric anatomic imaging, addressing image distortion because of magnetic field inhomogeneities, reproducible quantitative imaging across different MRI systems, and biologic validation of quantitative imaging. This review describes emerging innovations in offline and online MRI-guided RT, exciting opportunities they offer for advancing research and clinical care, hurdles to be overcome, and the need for multidisciplinary collaboration.

Towards real-time 4D radiation dosimetry on an MRI-Linac

4D radiation dosimetry using a highly radiation-sensitive polymer gel dosimeter with real-time quantitative magnetic resonance imaging (MRI) readout is presented as a technique to acquire the accumulated radiation dose distribution during image-guided radiotherapy on an MRI-Linac. Optimized T 2-weighted Turbo-Spin-Echo (TSE) scans are converted into quantitative ΔR 2 maps and subsequently to radiation dose maps.The concept of temporal uncertainty is introduced as a metric of effective temporal resolution. A mathematical framework is presented to optimize the echo time of the TSE sequence in terms of dose resolution, and the trade-off between temporal resolution and dose resolution is discussed. The current temporal uncertainty achieved with the MAGAT gel dosimeter on a 1 T MRI-Linac is 3.8 s which is an order of magnitude better than what has been achieved until now.The potential of real-time 4D radiation dosimetry in a theragnostic MRI-Linac is demonstrated for two scenarios: an irradiation with three coplanar beams on a head phantom and a dynamic arc treatment on a cylindrical gel phantom using a rotating couch. The dose maps acquired on the MRI-Linac are compared with a treatment plan and with dose maps acquired on a clinical 3 T MRI scanner. 3D gamma map evaluations for the different modalities are provided. While the presented method demonstrates the potential of gel dosimetry for tracking the dose delivery during radiotherapy in 4D, a shortcoming of the MAGAT gel dosimeter is a retarded dose response.The effect of non-ideal radiofrequency pulses resulting from limitations in the specific absorption rate or B1-field inhomogeneity on the TSE acquired ΔR 2 values is analysed experimentally and by use of computational modelling with a Bloch simulator.

OC-0703: Patterns of practice for adaptive and realtime radiation therapy: part I intra-fraction motion

OC-0703: Patterns of practice for adaptive and realtime radiation therapy: part I intra-fraction motion

PD-0311: Patterns of practice for adaptive and real-time radiation therapy part II: interfractional changes

PD-0311: Patterns of practice for adaptive and real-time radiation therapy part II: interfractional changes