Comparison of Radiation Doses for Different Techniques in Fluoroscopy-Guided Lumbar Facet Medial Branch Blocks: A Retrospective Cohort Study.

Chronic lumbar facet pain is commonly treated with fluoroscopy-guided facet medial branch blocks (FMBBs). However, the associated radiation exposure of both patients and clinicians is a growing concern. This study aimed to compare radiation doses and fluoroscopy times between two techniques, i.e., oblique and posterior-anterior (PA) fluoroscopic approaches, while also examining the impact of physician experience on these metrics. A retrospective analysis was conducted on 180 patients treated at Mersin University Hospital Pain Clinic between January and July 2024. Patients were divided into two groups: 90 received the oblique technique (Group O) and 90 received the AP technique (Group A). Radiation dose and fluoroscopy time data were collected for each patient. The AP technique was associated with significantly lower radiation doses (mean 66 mGy) and shorter fluoroscopy times (mean 28 s) compared to the oblique technique (mean radiation dose of 109 mGy and fluoroscopy time of 46 s) (p < 0.001). Physician experience also influenced these outcomes, with more experienced physicians consistently using less radiation. The AP technique should be considered for FMBBs, as it reduces radiation exposure while maintaining procedural efficiency, highlighting the importance of experience in optimizing outcomes.

Multi-Organizational Insights Into Radiological Safety Standards in High-Dose Rate Brachytherapy.

The review provides an extensive study of regulations and recommendations set forth by organizations worldwide in the domain of high-dose rate (HDR) brachytherapy for the prevention and mitigation of radiation hazards. The relevant reports and publications by the International Commission on Radiological Protection (ICRP), International Atomic Energy Agency (IAEA), American Association of Physicists in Medicine (AAPM), United States (US) Nuclear Regulatory Commission (NRC), and Atomic Energy Regulatory Board (AERB) were accessed, and necessary information was compiled to clarify and understand concepts, similarities, and differences in safety standards concerning to the topic. The regulations and guidance are categorized under three major components of safety, namely layout, equipment, and source. Layout category accesses structure, design, layout, and survey. The equipment category summarizes the requirements of equipment, installation, commissioning, quality assurance (QA) and performance, safety precautions and preparedness, safety procedures, and instructions. The source category includes requirements for sealed source possession and use, calibration, categorization, certification, licensing, QA tests, and security. IAEA gives inclusive guidance on radiation protection and regulatory requirements, forming the basis of reference for other organizations worldwide. AERB regulates the radiation facilities in India; therefore, most set-ups follow their safety standards and instructions.

Comprehensive Shielding System Enhances Radiation Protection for Structural Heart Procedures.

Background: This study of radiation exposure (RE) to physicians performing structural heart procedures evaluated the efficacy of a novel comprehensive radiation shield compared to those of traditional shielding methods. A novel comprehensive shielding system (Protego, Image Diagnostics Inc) has been documented to provide superior RE protection during coronary procedures compared to that provided by a standard "drop down" shield. The purpose of this study was to assess the efficacy of this shield in transcatheter aortic valve replacement (TAVR) procedures, which are associated with disproportionate RE to operators. Methods: This single-center, 2-group cohort, observational analysis compared RE to the primary physician operator performing TAVR using the Protego shield (n = 25) with that using a standard drop-down shield with personal leaded apparel (n = 25). RE was measured at both thyroid and waist levels with a real-time dosimetry system (RaySafe i3, RaySafe) and was calculated on a mean per case basis. Data were collected on additional procedural parameters, including access site(s) for device implantation, per case fluoroscopy time, air kerma, and patient factors, including body mass index. Between-group comparisons were conducted to evaluate RE by group and measurement sites. Results: The Protego system reduced operator RE by 99% compared to that using standard protection. RE was significantly lower at both the thyroid level (0.08 ± 0.27 vs 79.2 ± 62.4 µSv; P < .001) and the waist level (0.70 ± 1.50 vs 162.0 ± 91.0 µSv, P < .001). "Zero" total RE was documented by RaySafe in 60% (n = 15) of TAVR cases using Protego. In contrast, standard protection did not achieve zero exposure in a single case. Conclusions: The Protego shield system provides superior operator RE protection during TAVR procedures. This shield allows operators to work without the need for personal lead aprons and has potential to reduce catheterization laboratory occupational health hazards.

Radiation Exposure Using Rampart vs Standard Lead Aprons and Shields During Invasive Cardiovascular Procedures.

Background: Radiation exposure during invasive cardiovascular procedures remains an important health care issue. Lead aprons and shields (LAS) are used to decrease radiation exposure but leave large portions of the body unshielded. The Rampart IC M1128 is a portable radiation shielding system that may significantly attenuate radiation exposure. Methods: Catheterization laboratory teams were randomized in a 1:1 fashion to perform elective invasive cardiovascular procedures utilizing either traditional LAS or the Rampart IC M1128. Radiation exposure was measured using real-time dosimetry monitoring in prespecified anatomic locations on 3 operators (position 1: first operator/fellow; position 2: second operator/attending; and position 3: catheterization laboratory nurse/technologist). Radiation exposure was measured on a per-case basis. Results: In total, 100 consecutive cases were randomized in this study (47 Rampart; 53 LAS). There was no difference in fluoroscopy time (12.3 minutes for Rampart vs 15.4 minutes for LAS; P = .52), dose area product (288 Gy⋅cm2 for Rampart vs 376.5 Gy⋅cm2 for LAS; P = .52), or scatter radiation (38.8 mRem for Rampart vs 46.8 mRem for LAS; P = .61) between the groups. There was significantly lower total body radiation (in milliroentgen equivalent man) exposure using the Rampart than that using LAS for each team member: position 1-0.1 mRem for Rampart vs 2.2 mRem for LAS; P < .001; position 2-0.1 mRem Rampart vs 3.2 mRem LAS; P < .001; and position 3-0.0 mRem for Rampart vs 0.8 mRem for LAS; P < .001. Conclusions: During routine clinical procedures, the Rampart system significantly decreases total body radiation exposure compared with traditional LAS.

Radiation Doses to the Entire Catheterization Laboratory Team With a Novel Radiation Protection Device.

Background: A novel radiation protection system has recently been shown to shield the primary operator from scatter radiation, but whether it shields other members of the catheterization laboratory team remains unknown. Methods: Radiation exposure data were collected prospectively in 50 coronary angiography cases, in which 25 were completed using standard radiation protection and 25 with a novel system consisting of a series of rigid shields and flexible radiation-resistant drapes. Radiation doses, measured with real-time dosimeters, were compared between the 2 groups. Results: There were no significant differences between groups with respect to patient or procedural characteristics, including air kerma (P = .97) and dose area product (P = .17). The primary operator received a median head-level radiation dose of 0.0 [0.0, 0.0] µSv with the novel radiation protection system and 2.1 [0.7, 3.3] µSv with standard radiation protection (P < .001). Scrub technologists had a median head-level radiation dose of 0.0 [0.0, 0.0] µSv with the novel radiation protection system and 0.3 [0.1, 0.4] µSv with standard radiation protection (P < .001). The median head-level radiation dose among circulating nurses was 0.0 [0.0, 0.0] µSv with the novel radiation protection system and was 0.1 [0.0, 0.2] µSv with standard radiation protection (P < .001). Conclusions: Compared to standard radiation protection with lead aprons, use of a novel radiation protection system during coronary angiography was associated with significantly lower head-level radiation doses among all members of the catheterization laboratory team.

[Radiation Dose Considerations for Breast Sonographers Following 99mTc-HMDP Bone Scan Administration].

PURPOSE: Patients who were administered radiopharmaceuticals can be a source of radiation exposure to sonographers. This study aimed to identify factors associated with radiation exposure to breast sonographers from patients administered radiopharmaceuticals for bone scanning. METHODS: The exposure dose of six sonographers was measured during breast sonography in 59 patients administered 99mTc-HMDP. We predicted the following factors to be related to exposure dose: time interval between administration and sonography, sonography examination time, estimated radioactivity at sonography, sonographer's years of experience, and patients' clinical data (age, renal function and surgical procedure). Spearman's rank correlation coefficient was used to examine the relationship between radiation dose and the aforementioned factors. RESULTS: The mean±standard deviation of the exposure dose for the sonographers was 9.3±3.8 µSv. The time interval between administering the radiopharmaceutical agent and sonography, the sonography examination time and estimated radioactivity at sonography were found to be factors related to the exposure of the sonographer. The exposure dose increased as a function of the shorter time interval, longer examination time and higher estimated radioactivity at sonography. CONCLUSION: The time interval between drug administration and sonography, sonography examination time and estimated radioactivity at sonography contributed to the increased dose to breast sonographers. Although we considered that the exposure dose of sonographers would not possibly exceed the dose limit in the present study, we suggested that radiological technologists need to educate the physicians requesting sonography, and the sonographers about the radiation exposure in nuclear medicine.

Enhancing radiation safety awareness and practices among female radiographers: a comprehensive approach.

OBJECTIVE: This study evaluates the level of radiation safety awareness and adherence to protective practices among pregnant female radiographers in the United Arab Emirates, aiming to identify gaps and develop targeted interventions for enhancing occupational safety. METHODS: Employing a cross-sectional design, the study surveyed 133 female radiographers using a self-developed questionnaire covering demographics, awareness and knowledge, workplace practices, communication, and satisfaction. RESULTS: The survey showed high awareness among radiographers, with 97% acknowledging radiation risks during pregnancy, although 42.9% had not received formal training. Concerns over long-term health effects were significant, with 66.2% of participants worried about potential impacts. Despite these concerns, 83.5% had been informed about radiation risks and protective measures, indicating active information provision in many workplaces. However, inconsistencies in information dissemination across different work settings were noted. CONCLUSIONS: The findings highlight the need for standardized radiation safety protocols for pregnant radiographers. The variability in safety training and information dissemination suggests the importance of establishing uniform safety practices. Recommendations include developing comprehensive education and training programs for pregnant radiographers, ensuring open communication for radiation safety and pregnancy-related concerns, and enforcing clear guidelines for workplace accommodations.

Implementing a 'Lead [Apron]-Free' Cardiac Catheterization: Current Status.

PURPOSE OF REVIEW: In this review, we discuss the status of novel radiation shielding and other methods to reduce radiation exposure and its associated health risks within the CCL. RECENT FINDINGS: There are many devices on the market each with its unique advantages and inherent flaws. Several are available for widespread use with promising data, while others still in development. The field of percutaneous transcatheter interventions includes complex procedures often involving significant radiation exposure. Increased radiation exposes the proceduralist and CCL staff to potential harm from both direct effects of radiation but also from the ergonomic consequences of daily use of heavy personal protective equipment. Here we discuss several innovative efforts to reduce both radiation exposure and orthopedic injury within the CCL that are available, leading to a safer daily routine in a "lead [apron]-free" environment.

Feasibility of safe outpatient treatment in pediatric patients following intraventricular radioimmunotherapy with 131I-omburtamab for leptomeningeal disease.

BACKGROUND: Radiolabeled antibody 131I-omburtamab was administered intraventricularly in patients with leptomeningeal disease under an institutionally approved study (#NCT03275402). Radiation safety precautions were tailored for individual patients, enabling outpatient treatment based on in-depth, evidence-based recommendations for such precautions. The imperative advancement of streamlined therapeutic administration procedures, eliminating the necessity for inpatient isolation and resource-intensive measures, holds pivotal significance. This development bears broader implications for analogous therapies within the pediatric patient demographic. METHODS: Intraventricular radioimmunotherapy (RIT) with 925-1850 MBq (25-50 mCi) of 131I-omburtamab was administered via the Ommaya reservoir, in designated rooms within the pediatric ambulatory care center. Dosimeters were provided to staff involved in patient care to evaluate exposure during injection and post-administration. Post-administration exposure rate readings from the patient on contact, at 0.3 m, and at 1 m were taken within the first 30 min, and the room was surveyed after patient discharge. Duration of radiation exposure was calculated using standard U.S. Nuclear Regulatory Commission (US NRC) regulatory guidance recommendations combined with mean exposure rates and whole-body clearance estimates. Exposure rate measurements and clearance data provided patient-specific precautions for four cohorts by age: < 3 y/o, 3-10 y/o, 10-18 y/o, and 18+. RESULTS: Post-administration exposure rates for patients ranged from 0.16 to 0.46 µSv/hr/MBq at 0.3 m and 0.03-0.08 µSv/hr/MBq at 1 m. Radiation exposure precautions ranged from 1 to 10 days after release for the four evaluated cohorts. Based on the highest measured exposure rates and slowest whole-body clearance, the longest precautions were approximately 78% lower than the regulatory guidance recommendations. Radiation exposure to staff associated with 131I-omburtamab per administration was substantially below the annual regulatory threshold for individual exposure monitoring. CONCLUSION: 131I-omburtamab can be administered on an outpatient basis, using appropriate patient-based radiation safety precautions that employ patient-specific exposure rate and biological clearance parameters. This trial is registered with the National Library of Medicine's ClinicalTrials.gov. The registration number is NCT03275402, and it was registered on 7 September 2017. The web link is included here. https://clinicaltrials.gov/study/NCT03275402 .

Comparing Radiation Doses in CBCT and Medical CT Imaging for Dental Applications.

Background: Dental imaging plays a crucial role in diagnosis and treatment planning, with cone-beam computed tomography (CBCT) and medical computed tomography (CT) being two common modalities. This study aims to compare the radiation doses associated with CBCT and medical CT imaging in dental applications to assess their relative safety and efficacy. Materials and Methods: We conducted a retrospective study using data from 100 patients who underwent both CBCT and medical CT scans for dental purposes. The radiation doses were measured in terms of dose-length product (DLP) for medical CT and dose-area product (DAP) for CBCT. The effective dose (ED) was calculated using appropriate conversion factors. Patient demographics, scan parameters, and radiation doses were recorded and analyzed. Results: The results indicated that the mean DLP for medical CT scans was 220 mGycm, whereas the mean DAP for CBCT scans was 150 mGycm². The corresponding mean effective doses for medical CT and CBCT were 2.5 mSv and 1.8 mSv, respectively. The radiation dose from CBCT was found to be approximately 28% lower than that from medical CT. Conclusion: This study demonstrates that CBCT imaging for dental applications results in significantly lower radiation doses compared to medical CT. While both modalities provide valuable diagnostic information, the choice of imaging technique should consider the balance between diagnostic quality and radiation exposure, especially for pediatric and high-risk patients. Dental practitioners should be aware of the potential dose reduction benefits associated with CBCT when appropriate for the clinical scenario.

Radiation safety of ultra-high dose rate electron accelerators for FLASH radiotherapy.

BACKGROUND: An ultra-high dose rate (UHDR) electron accelerator for FLASH radiotherapy (RT) produces very intense bremsstrahlung by the interaction of the electron beam with objects both inside and outside of the accelerator. The bremsstrahlung dose per pulse is typically 1-2 orders of magnitude larger than that of conventional RT x-ray treatment of the same energy, and for electron energies above 10 MeV, the bremsstrahlung produces substantially more induced radioactivity outside the accelerator than for conventional RT. Therefore, a thorough radiation safety assessment is mandatory prior to the operation of a UHDR electron accelerator. PURPOSE: To evaluate the radiation safety of a prototype FLASH-enabled Varian TrueBeam accelerator and to develop a general framework for assessment of all key radiation safety properties of a UHDR electron accelerator for FLASH RT. METHODS: Production of bremsstrahlung and induced radioactivity by a UHDR electron accelerator is modeled by various analytical methods. The analytical modeling is compared with National Institute of Standards and Technology (NIST) bremsstrahlung yield data as well as measurements of primary bremsstrahlung outside the bunker and induced radioactivity of irradiated thick targets for a FLASH-enabled 16 MeV Varian TrueBeam electron accelerator. In addition, the analytical modeling is complemented by measurements of secondary bremsstrahlung inside/outside the bunker and neutrons at the maze entrance. RESULTS: Calculated bremsstrahlung yields deviate maximum 8.5% from NIST data, and all measurements of primary bremsstrahlung and induced radioactivity agree with calculations, validating the analytical tools. In addition, it is found that scattering foil bremsstrahlung dominates primary bremsstrahlung and the main source of secondary bremsstrahlung is the irradiated object outside the accelerator. It follows that primary and secondary bremsstrahlung outside the bunker can be calculated using the same simple formalism as that used for conventional RT. Measured primary bremsstrahlung tenth-value layers for concrete of the simple formalism are in good agreement with NCRP and IAEA data, while measured secondary bremsstrahlung tenth-value layers for concrete are considerably lower than NCRP and IAEA data. All calculations and measurements form a general framework for assessment of all key radiation safety properties of a UHDR electron accelerator. CONCLUSIONS: The FLASH-enabled Varian TrueBeam accelerator is safe for normal operation (max. 99 pulses per irradiation) in a bunker designed for at least 15 MV conventional x-ray treatment unless the UHDR workload is much larger than the x-ray workload. A similar finding applies to other UHDR electron accelerators. However, during beam tuning, radiation survey, or other tests with extended irradiation time, the UHDR workload may become very large, necessitating the implementation of additional safety measures.

Facilitating the End of the Linear No-Threshold Model Era.

The linear no-threshold (LNT) model, which asserts that any level of ionizing radiation increases cancer risk, has been the basis of global radiation protection policies since the 1950s. Despite ongoing endorsements, a growing body of evidence challenges the LNT model, suggesting instead that low-level radiation exposure might reduce cancer risk, a concept known as radiation hormesis. This editorial examines the persistence of the LNT model despite evidence favoring radiation hormesis and proposes a solution: a public, online debate between proponents of the LNT model and advocates of radiation hormesis. This debate, organized by a government agency like Medicare, would be transparent and thorough, potentially leading to a shift in radiation protection policies. Acceptance of radiation hormesis could significantly reduce cancer mortality rates and streamline radiation safety regulations, fostering medical innovation and economic growth.

Intraindividual Comparison of Dose Reduction and Coronary Calcium Scoring Accuracy Using Kilovolt-independent and Tin Filtration CT Protocols.

Purpose To investigate the ability of kilovolt-independent (hereafter, kV-independent) and tin filter spectral shaping to accurately quantify the coronary artery calcium score (CACS) and radiation dose reductions compared with the standard 120-kV CT protocol. Materials and Methods This prospective, blinded reader study included 201 participants (mean age, 60 years ± 9.8 [SD]; 119 female, 82 male) who underwent standard 120-kV CT and additional kV-independent and tin filter research CT scans from October 2020 to July 2021. Scans were reconstructed using a Qr36f kernel for standard scans and an Sa36f kernel for research scans simulating artificial 120-kV images. CACS, risk categorization, and radiation doses were compared by analyzing data with analysis of variance, Kruskal-Wallis test, Mann-Whitney test, Bland-Altman analysis, Pearson correlations, and κ analysis for agreement. Results There was no evidence of differences in CACS across standard 120-kV, kV-independent, and tin filter scans, with median CACS values of 1 (IQR, 0-48), 0.6 (IQR, 0-58), and 0 (IQR, 0-51), respectively (P = .85). Compared with standard 120-kV scans, kV-independent and tin filter scans showed excellent correlation in CACS values (r = 0.993 and r = 0.999, respectively), with high agreement in CACS risk categorization (κ = 0.95 and κ = 0.93, respectively). Standard 120-kV scans had a mean radiation dose of 2.09 mSv ± 0.84, while kV-independent and tin filter scans reduced it to 1.21 mSv ± 0.85 and 0.26 mSv ± 0.11, cutting doses by 42% and 87%, respectively (P < .001). Conclusion The kV-independent and tin filter research CT acquisition techniques showed excellent agreement and high accuracy in CACS estimation compared with standard 120-kV scans, with large reductions in radiation dose. Keywords: CT, Cardiac, Coronary Arteries, Radiation Safety, Coronary Artery Calcium Score, Radiation Dose Reduction, Low-Dose CT Scan, Tin Filter, kV-Independent Supplemental material is available for this article. © RSNA, 2024.

Commissioning of the first hospital-based PET radiopharmaceutical cyclotron in Greece: personnel dose assessment.

The role of18F-fluoro-deoxy-glucose in positron emission tomography (PET) imaging is well established in diagnosis and management of cancer patients. Installations of on-site self-shielded mini cyclotrons are increasing. The Dose on Demand Biomarker Generator BG-75 was installed at Metaxa Cancer Hospital, Greece, in May 2021 and is the first hospital-based PET radiopharmaceutical cyclotron in the country. Personnel expected external exposure was established during commissioning; internal exposure is not expected. Personnel dose was estimated with two methods: survey meter measurements in various locations combined with the time spent in each location, and direct measurement using electronic personal dosemeters. Gamma and neutron radiation readings outside the cyclotron vault were at background levels. Inside the cyclotron vault, the highest recorded radiation readings by the target were 18µSv h-1for both gammas and neutrons with cyclotron in operational mode; at one meter, the values were 5µSv h-1and 4µSv h-1, respectively. The annual expected whole body dose per cyclotron operator is 0.6 mSv, and the respective extremity dose 16 mSv. The annual expected whole body and extremity dose for the radiochemist is 0.3 mSv and 25 mSv, respectively. The respective annual dose estimates for the medical physicists are < 1 mSv. The expected personnel doses are well below the regulatory limits and local as low as reasonably achievable (ALARA) levels. With experience and a robust ALARA program, personnel exposure could be further reduced.

Assessing the Efficacy of RADPAD Protection Drape in Reducing Radiation Exposure to Operators in the Cardiac Catheterization Laboratory: A Systematic Review and Meta-Analysis.

One of the leading environmental hazards, ionizing radiation, is linked to several detrimental health consequences in the body. RADPAD (Worldwide Innovations & Technologies, Inc., Kansas City, Kansas) is a sterile, lead-free, lightweight, disposable radiation protection shield. We conducted a systematic review and meta-analysis to determine the effectiveness of RADPAD protection drapes in the cardiac catheterization lab and how they can aid interventional cardiologists in becoming subjected to less scatter radiation. PubMed, Embase, and Google Scholar were searched for studies discussing the efficacy of RADPAD protection drapes in reducing radiation exposure to operators in the cardiac catheterization laboratory. A random-effects model was used to pool odds ratios (ORs) and 95% confidence intervals (CIs) for endpoints: primary operator exposure dose, dose area product (DAP), relative exposure, and screening time. Our analysis included 892 patients from six studies. Compared to the No-RADPAD group, primary operator exposure dose (E) was significantly lower in the RADPAD group (OR: -0.9, 95% CI: -1.36 to -0.43, I2 = 80.5%, p = 0.0001). DAP was comparable between both groups (OR: 0.008, 95% CI: -0.12 to -0.14, I2 = 0%, p = 0.9066). There was no difference in the relative exposure (E/DAP) (OR: -0.47, 95% CI: -0.96 to 0.02, I2 = 0%, p = 0.90) and screening time (OR: 0.13, 95% CI: 0.08 to 0.35, I2 = 0%, p = 0.22) between the two groups. The interventional cardiology laboratory is exposed to significantly less scatter radiation during procedures owing to the RADPAD protective drape. Consequently, all catheterization laboratories could be advised to employ RADPAD protective drapes.

Radiation Safety Assessment in Prostate Cancer Treatment: A Predictive Approach for I-125 Brachytherapy.

This study uses Monte Carlo simulation and experimental measurements to develop a predictive model for estimating the external dose rate associated with permanent radioactive source implantation in prostate cancer patients. The objective is to estimate the accuracy of the patient's external dose rate measurement. First, I-125 radioactive sources were implanted into Mylar window water phantoms to simulate the permanent implantation of these sources in patients. Water phantom experimental measurement was combined with Monte Carlo simulation to develop predictive equations, whose performance was verified against external clinical data. The model's accuracy in predicting the external dose rate in patients with permanently implanted I-125 radioactive sources was high (R2 = 0.999). A comparative analysis of the experimental measurements and the Monte Carlo simulations revealed that the maximum discrepancy between the measured and calculated values for the water phantom was less than 5.00%. The model is practical for radiation safety assessments, enabling the evaluation of radiation exposure risks to individuals around patients with permanently implanted I-125 radioactive sources.

Frugal and Translatable [15O]O2 Production for Human Inhalation with Direct Delivery from the Cyclotron to a Hybrid PET/MR.

Oxygen-15 (ß+, t1/2 = 122 s) radiolabeled diatomic oxygen, in conjunction with positron emission tomography, is the gold standard to quantitatively measure the metabolic rate of oxygen consumption in the living human brain. We present herein a protocol for safe and effective delivery of [15O]O2 over 200 m to a human subject for inhalation. A frugal quality control testing procedure was devised and validated. This protocol can act as a blueprint for other sites seeking to implement similar imaging programs.