The Rocky Flats (RFs) Plant operated from 1951-1989 as part of the U.S. Department of Energy (DOE) nuclear complex. Its primary mission was weapons component fabrication, whereby workers were potentially exposed to radioactive and non-radioactive hazards. RF worker mortality was compared to the general population, and dose-response relationships between mortality and radiation organ doses were examined. RF workers first employed between 1951 and 1979 for ⩾30 d were identified (n= 9397). Vital status was determined using national and state death records up to 2017. Organ doses from external photons and neutrons irritation and internalised plutonium (Pu), americium (Am), and uranium (U) were modelled as cumulative lagged total doses per year. Beryllium exposure was evaluated as an effect modifier using data from the DOE Nationwide Beryllium Medical Program. Statistical analyses included standardised mortality ratios (SMRs), Cox proportional hazard models, and excess relative risk (ERR) models. Approximately 53.2% of workers were deceased by the end of the study. Nearly 90% were monitored for radiation exposure, with a mean weighted absorbed dose of 59.0 mGy for the lungs. Nearly 45% of workers had intakes of alpha-particle emitting radionuclides, and 46.7% were monitored for neutrons. Leading causes of death included ischemic heart disease (n= 999) and lung cancer (n= 361). The highest SMRs were observed for berylliosis (SMR: 176.9; 95% CI: 76.2, 348.7;n< 10) and asbestosis (SMR: 4.65; 95% CI: 2.23, 8.55;n= 10). Dose-response analyses showed no statistical increase in risk from low-dose radiation including lung cancer (ERR per 100 mGy: -0.02; 95% CI: -0.11, 0.08;n= 361) and Parkinson's disease (ERR per 100 mGy: 0.13; 95% CI: -0.26, 0.31;n= 57). Approximately 45% of workers were monitored for beryllium, with a weak non-significant indication of effect modification for lung cancer risk. The RF cohort showed no evidence of a statistically significant increase in mortality from occupational radiation exposure. However, this study was limited by low statistical power, which inhibits the ability to detect effects. Future pooling of Million Person Study (MPS) cohorts will provide further insights, particularly regarding Pu as a carcinogen.

Patients treated for head and neck cancer (HNC) receive incidental, non-target radiation to intracranial structures. This prospective study investigated the relationship between regional brain radiation dosimetry and neurocognitive performance during the first year of survivorship. Patients with newly diagnosed HNC completed a comprehensive neuropsychological battery at baseline-prior to or within the first week of radiation therapy, or before induction chemotherapy-(n = 47), and again at 6 months (n = 30) and 12 months (n = 24) after initiating radiation therapy. Cognitive domains assessed included language, learning and memory, and attention, processing speed, and executive function (APE). Deep-learning-assisted contouring was applied to estimate mean radiation doses (Dmean) to eight brain regions. Associations between regional dosimetry and cognitive change were evaluated using Pearson correlation coefficients with 95% confidence intervals (CIs). The highest median Dmean were observed in the cerebellum (430.7 cGy; IQR: 302.3-646.2) and temporal lobes (108.5 cGy; IQR: 72.4-161.2), while the parietal lobe received the lowest (27.5 cGy; IQR: 18.9-39.6). Neurocognitive scores demonstrated modest improvement across domains at both follow-up time points. No significant correlations were identified between region-specific doses and cognitive performance, with most estimates between -0.1 and 0.1. Incidental brain radiation during HNC treatment was not associated with early neurocognitive decline within the first year after diagnosis. This prospective study illustrates the utility of integrating advanced dosimetry with longitudinal cognitive assessments and lays the groundwork for future larger-scale investigations.

Borated polyethylene (PE) is an effective neutron moderator and absorber in medical linear accelerator shielding; however, there is limited data regarding the required material thickness for adequate neutron attenuation. To address the gap in shielding data, our study systematically quantifies first and equilibrium tenth-value layers (TVLs1 and TVLe) for PE containing 0%, 5% and 30% natural boron by weight from thermal to fast neutrons. Comprehensive Monte Carlo simulations (n= 3504) were performed to estimate TVL thicknesses from thermal to 20 MeV neutrons. A current tally was used to count neutrons exiting the shield and determine thicknesses corresponding to 10% and 1% transmission. Sixteen energies and 73 thicknesses of materials were modelled with statistical uncertainties below 3%. TVL thicknesses were independently validated with particle and heavy ion transport code system using identical simulation parameters. We found that TVL values ranged from 1.3 mm for thermal neutrons in borated polyethylene (BPE), to 50 cm for 20 MeV neutrons in pure PE. In all cases, adding boron to PE reduced the TVL, with the greatest effect at thermal energies, and a smallest effect at 12 MeV. Here we provide the first comprehensive characterisation of BPE's ability to attenuate neutrons, supporting shielding design for medical linear accelerators.

Emerging evidence from terrestrial cohorts suggests that ionizing radiation (IR) exposure may increase the risk of Parkinson’s disease (PD). Understanding the biological mechanisms underlying IR-induced PD is therefore critical for assessing health risks, particularly in the context of long-duration missions to the Moon and Mars. This perspective explores mechanistic pathways that may support causal links between IR and PD and highlights experimental and epidemiological approaches relevant for strengthening causal inference.

A cohort mortality study was conducted of 123,401 industrial radiographers in the United States to estimate risks following protracted radiation exposures. The cohort was constructed from the Nuclear Regulatory Commission Radiation Exposure Information Reporting System and the Landauer, Inc. dosimetry databases. Workers were monitored between 1939 and 2011 and were exposed mainly to external gamma radiation from 192Ir and 60Co. Causes of death were obtained from the National Death Index and state mortality files with follow-up through 2019. The mean duration of follow-up was 27.7 years. Nearly 19% of workers were monitored for more than 10 years. There were 30,617 (24.8%) who worked at shipyards and 5,071 (4.1%) at nuclear power plants with the potential for asbestos exposure. The mean radiation dose to the red bone marrow (RBM) was 15.2 mGy (maximum 1.24 Gy; percent >100 mGy was 3.6%), 17.2 mGy to lung, 18.1 mGy to colon, 11.9 mGy to brain, and 18.1 mGy to heart. Overall, 30,560 deaths occurred; the Standardized Mortality Ratio and 95% confidence interval for all-cause mortality was 0.92 95% CI (0.91, 0.93); for all solid cancers 1.01 (0.99, 1.03; n = 7,734); for ischemic heart disease (IHD) 0.83 (0.81, 0.85; n = 5,820); for cerebrovascular disease (CeVD) 0.88 (0.83, 0.93; n = 1,257); for mesothelioma 6.08 (5.35, 6.89; n = 248); and for asbestosis 13.4 (11.2, 15.9; n = 134). The Cox linear excess relative risk (ERR) per 100 mGy (95% CI) for leukemia (excluding CLL) was 0.45 (0.05, 0.85) and for non-Hodgkin lymphoma (NHL) was 0.33 (0.04, 0.62). For all solid cancers it was 0.06 (0.02, 0.10); lung cancer 0.11 (0.04, 0.19); all solid cancers excluding lung cancer and mesothelioma 0.02 (-0.03, 0.07); Parkinson's disease 0.24 (-0.13, 0.61); IHD -0.03 (-0.06, 0.01); and CeVD 0.05 (-0.08, 0.17). The ERR per 100 mGy for chronic obstructive pulmonary disease (COPD) was 0.19 (0.08, 0.30) and was similar in magnitude to that for lung cancer. This finding suggests that residual confounding by smoking may have influenced the results, warranting cautious interpretations. No significant association was found between cumulative radiation exposure and all solid cancers after excluding lung cancer and mesothelioma, nor for IHD or CeVD. The marginally non-significant increased risk of Parkinson's disease, also seen in other Million Person Study cohorts, requires further investigation. Early workers monitored entirely before 1979 had the same linear ERR per 100 mGy for solid cancers [0.06 (0.00, 0.12) n = 3,587] as for all other more contemporary workers monitored after 1978 [0.07 (0.01,0.13) n = 4,150]. This report provides convincing evidence that low-dose and low-dose-rate exposures over time significantly increases the risk of leukemia (excluding CLL) following cumulative doses up to 200 mGy while also providing information on early versus contemporary workers.

The accurate reconstruction of external photon doses is essential for credible radiation epidemiology. This article presents the methodology used to derive dose estimates for 37 012 Hanford Site workers included in the Million Person Study. The approach employs historical dose records from the Hanford Radiation Exposure database and a previous epidemiology study. Bias correction factors specific to dosimeter type and period of use were applied and missing annual doses were estimated using a hierarchical nearby method to estimate deep dose equivalent for each worker. For early years with limited detection sensitivity, missed doses were quantified based on expected time-period-specific, low-dose statistical distributions. The revised dose estimates resulted in lower median and mean career doses than unadjusted data, while increasing the number of person-years with nonzero dose. Sensitivity analyses assessed the influence of bias in dosimetry measurements, missed doses and gap years on dose estimates. Differences in cumulative dose estimates between unadjusted and revised annual estimates are most prominent in the early operational years due to the highest bias during that time period.

An evaluation is presented of differences in radiation-related solid cancer mortality risk for early versus contemporary sub-groups of radiation workers in both of the two constituent Million Person Study (MPS) cohorts. The two previously analyzed MPS cohorts are 123,401 industrial radiographers monitored from 1939-2011 and followed through 2019 and 135,193 nuclear power plant workers monitored from 1957-1984 and followed through 2011. The rationale behind this extended new analysis is to investigate if these two MPS cohorts support recently published increased risks for contemporary workers in a different cohort, The International Nuclear Workers Study (INWORKS) with pooled U.S., French and UK nuclear worker data, particularly for the U.S. component. The US-INWORKS contributed about one-third of the workers to the full-INWORKS study based on 309,932 workers. For all solid cancer mortality, the US-INWORKS study reported a low and non-significant excess relative risk (ERR) per Sv cumulative equivalent dose for the whole cohort of 0.19 (95% CI: -0.10; 0.52), whereas for contemporary workers the ERR per Sv was 2.23 (95% CI: 1.13, 3.49), approximately 10 times higher than the entire US-INWORKS cohort. The risk for the full INWORKS cohort was 0.52 (90% CI: 0.27; 0.77) per Gy colon dose whereas, for contemporary workers, the risk was 1.44 (90% CI: 0.65, 2.32), nearly 3 times higher. These risks for contemporary workers are both larger than risks informing radiation protection and much higher (7.0 and 4.5 times) than the Japanese A-bomb survivor's risk for males exposed acutely between the ages of 20 and 60 years of 0.32 (95% CI: 0.01; 0.50). Limitations include missing information on organ doses from radionuclide intake, neutrons and the absence of adjustment for non-radiation risk factors (notably asbestos exposure). The analysis of the MPS cohorts addresses these dosimetric- and asbestos-related limitations. For all solid cancer mortality, industrial radiographers showed equal Poisson ERRs per 100 mGy colon dose for early and contemporary workers: 0.06 (95% CI: 0.00; 0.12) and 0.07 (95% CI: 0.01; 0.13), respectively. The results for nuclear power plant workers were 0.10 (95% CI: -0.09; 0.29) and 0.02 (95% CI: -0.02; 0.06), respectively. It appears premature to conclude that there is generally a difference in excess risk between early and contemporary workers from radiation exposures.

The American radium dial worker (RDW) cohort of over 3200 persons is being revisited as part of the Million Person Study (MPS) to include a modern approach to RDW dosimetry. An exceptional source of data and contextualization in this project is an extensive collection of electronic records (digitized from existing microfilm and microfiche) housed at the United States Transuranium and Uranium Registries (USTUR). Although the type, extent, and quality (e.g. legibility) of record(s) varies between individuals, the remarkable occupational, medical and demographic data include in vivo radiation measurements (e.g. radon breath, whole body counts), autopsy results, medical records (including copies of radiographs), interviews over the years, and correspondence. Of particular dosimetric interest are the details of radiation measurements. For example, there are some instances where hand-written and transcribed values are both available, along with notes providing context for why a particular measurement in a series of measurements was chosen to assign an intake, or if there were concerns about a particular measurement. Born prior to 1935, RDW have nearly all passed away. Thus, the updated dosimetry, especially for the skeletal tissues, will allow the correlation of lifetime cumulative dose with radiation risk. Here we review typical information available in this collection of historical records and highlight some interesting finds. Additionally, we discuss the relevance to current and ongoing work related to updating the dosimetry of the RDW in the MPS, including providing an example of the usefulness of information contained in these records. The RDW cohort provides a unique historical perspective on occupational exposure to radium, making it a valuable dataset for understanding long-term health effects and improving current radiation protection standards.

The International Radiation Protection Association established a task group (TG) in 2023 to collect data on knowledge and understanding of tissue reactions involving the eye lens, skin and cardiovascular system among radiation protection practitioners. The aim was to contribute to the sharing of experiences and raise awareness within the radiation protection community about tissue reactions. In 2024, the TG conducted a survey through a questionnaire and this paper provides an analysis and overview of the results.

Colossus is designed to meet a growing need for survival analysis software capable of analyzing tens of millions of rows of radiation epidemiological data. Colossus is an R package devised to offer scalable survival analysis for the Million Person Study. The total and relative rate equations available in Colossus are outlined in this article, which are used in conjunction with Cox proportional hazards, Poisson, and Fine-Grey regression models. Following a comparison with existing software, validation with epidemiological cohort data is described. Exposure data and specific causes of death among workers at Los Alamos National Laboratory and U.S. nuclear power plants were analyzed by Colossus and 32-bit Epicure and compared with published results. Colossus results agreed with the results of existing software and previous publications.

Software to fit complex models using big data sets is needed to answer persistent and emerging questions in radiation epidemiology. The open-source R package Colossus was developed to meet this need. Colossus was designed to take advantage of the input and graphing flexibility of R scripts, employ multi-core systems to run analyses faster, and permit the straightforward addition of future capabilities. Incorporating methods to propagate covariate uncertainty into model parameter uncertainty is the next major focus area. Through guidance from NCRP Commentary 34, methods of analysing multiple realisations of exposure were implemented in Colossus. Frequentist model averaging and Monte Carlo maximum likelihood programs were added to Colossus to provide different methods of applying complex risk models to datasets with intricate exposure uncertainties.

Importance Short and long sleep durations are adversely associated with cardiovascular disease (CVD), type 2 diabetes, and mortality. It remains unclear how sleep duration trajectories over time are associated with mortality and whether these associations vary by well-documented sex, race, and socioeconomic sleep disparities. Objective To investigate the association of 5-year sleep duration trajectories with all-cause and cause-specific mortality among US adults, predominantly those in low-income groups. Design, Setting, and Participants The Southern Community Cohort Study included participants aged 40 to 79 years recruited and enrolled (from March 2002 to September 2009) from community health centers by using random sampling methods across 12 states in the Southeastern US. Participants completed a follow-up survey between 2008 and 2013. Data analysis was performed from August 10 to November 30, 2023. Exposures Sleep duration was self-reported at study enrollment and at 5-year follow-up. At each time point, sleep was categorized as short (<7 hours), healthy (7-9 hours), or long (>9 hours). Nine sleep trajectories were defined based on 5-year change or consistency in sleep duration category between enrollment and follow-up. Main Outcome and Measures Cause of death was ascertained via linkage to the National Death Index through December 31, 2022. Multivariable-adjusted Cox proportional hazards regression analysis was performed to estimate hazard ratios (HRs) and 95% CIs for mortality outcomes (all-cause, CVD, cancer, and neurodegenerative disease) associated with sleep duration trajectory. Results Participants included 46 928 adults (mean [SD] age, 53.0 [8.8] years; 65.4% women; 63.3% self-identified as Black and 36.7% as White; and 47.5% with a household income <$15 000 per year). Overall, 66.4% of participants had suboptimal 5-year sleep trajectories. Race varied across sleep trajectories; 53.0% of participants in the optimal trajectory were Black, compared with 84.5% in the long-short trajectory. During a median 12.6 (IQR, 11.3-13.1) years of follow-up, 13 579 deaths occurred (4135 from CVD, 3067 from cancer, and 544 from neurodegenerative diseases). Compared with the optimal sleep duration trajectory, suboptimal trajectories were associated with as much as 29% greater risk of all-cause mortality in fully-adjusted models. For all-cause and CVD-specific mortality, the long-long (HRs, 1.27 [95% CI, 1.14-1.41] and 1.22 [95% CI, 1.01-1.48], respectively) short-long (HRs, 1.29 [95% CI, 1.17-1.42] and 1.22 [95% CI, 1.03-1.45], respectively), and long-short (HRs, 1.19 [95% CI, 1.05-1.35] and 1.32 [95% CI, 1.07-1.63], respectively) trajectories were associated with the greatest risk. After adjustment for comorbid conditions, no associations were observed for mortality due to cancer or neurodegenerative disease. Observed associations varied by race and household income, with the greatest risk observed among White adults with greater household incomes. Conclusions and Relevance In this cohort study of 46 928 US residents, nearly two-thirds of participants had suboptimal 5-year sleep duration trajectories. Suboptimal sleep duration trajectories were associated with as much as a 29% increase in risk of all-cause mortality. These findings highlight the importance of maintaining healthy sleep duration over time to reduce mortality risk.

The radium dial painters (RDPs) are a well-described group of predominantly young women who incidentally ingested226Ra and228Ra as they painted luminescent watch dials in the first part of the twentieth century. In 1974 pathologist Dr William D. Sharpe published complete clinical and autopsy results for 42 former RDPs evaluated in the New Jersey Radium Research Project. This was an important paper due to the completeness of the observations. Surprisingly, in this study, clinicians noted a 35.5% incidence of hearing loss, both conductive and mixed etiologies. Since the 1974 publication, there has developed a considerable literature on radiation-induced hearing loss in patients undergoing radiotherapy for head and neck cancers. It is expected that hearing loss would also be associated with systemic inflammation. Recently, the neutrophil to lymphocyte ratio (NLR) has been shown in many cancer and non-cancer studies to be a nonspecific marker of inflammation. In prior collaborative efforts with the United States Transuranium and Uranium Registries and with the NCRP Million Person Study, it has been possible to evaluate NLR from medical records of a cohort of 166 former RDPs previously evaluated at Argonne National Laboratory. In addition, NLR was available in historic medical records of the sarcoma and nasopharyngeal cancer patients described in Rowland's summary of the Argonne studies. Using elevation of the NLR as a non-specific marker of inflammation, chronic inflammation has been observed in all cohorts with significant dose. The RDP cohort has had a unique exposure to radium, but the incidence of radiation-induced hearing loss here is uncertain. Due to cosmic radiation dose to astronauts in space flight, there is a significant interest in high LET radiation dose to the brain, including the auditory system. This paper should be considered as hypothesis generating-that high LET radiation dose to the brain and auditory system may induce hearing loss.

Since 1968, the United States Transuranium and Uranium Registries (USTUR) has studied the biokinetics and tissue dosimetry of uranium and transuranium elements in nuclear workers. As part of the USTUR collaboration with the Million Person Study of Low-Dose Health Effects, radiation dose to different parts of the human heart is being estimated for workers with documented intakes of 239Pu or 226Ra. The study may be expanded for workers with intakes of 238U and other radionuclides. The distribution of radionuclides, expressed in terms of concentration (Bq per kg of tissue) serves as an important parameter for estimating radiation dose. Based on available organs from workers who donated their bodies or tissues for research, nine undissected hearts were selected: seven from USTUR registrants with plutonium exposure (males) and two individuals with radium intakes (female and male). For the plutonium workers, estimated 239Pu systemic deposition ranged from <74 Bq to 1765 Bq. Estimated 226Ra 'initial systemic intakes' were 10.1 MBq and 14.8 kBq for the female patient and male worker, respectively. Organ dissection was based on a heart model published by Borrego et al (2019 J. Radiol. Prot. 39 950-65). This model includes nine cardiac substructures: aorta, left main coronary artery, left atrium, left anterior descending artery, left circumflex artery, left ventricle, right atrium, right coronary artery, and right ventricle. In addition, heart valves, fat attached to epicardium, fluids, and a coronary bypass graft were collected resulting in 111 samples that are currently undergoing radiochemical analyses and mass-spectrometric measurements. The 239Pu and 226Ra evaluations are not completed. The results of this study are intended to support radiation worker health studies by improving associated dosimetric and epidemiological models.

BACKGROUND:Epidemiologic studies of radiation-exposed populations form the basis for human safety standards. They also help shape public health policy and evidence-based health practices by identifying and quantifying health risks of exposure in defined populations. For more than a century, epidemiologists have studied the consequences of radiation exposures, yet the health effects of low levels delivered at a low-dose rate remain equivocal. MATERIALS AND METHODS:The Million Person Study (MPS) of U.S. Radiation Workers and Veterans was designed to examine health effects following chronic exposures in contrast with brief exposures as experienced by the Japanese atomic bomb survivors. Radiation associations for rare cancers, intakes of radionuclides, and differences between men and women are being evaluated, as well as noncancers such as cardiovascular disease and conditions such as dementia and cognitive function. The first international symposium, held November 6, 2020, provided a broad overview of the MPS. Representatives from four U.S. government agencies addressed the importance of this research for their respective missions: U.S. Department of Energy (DOE), the Centers for Disease Control and Prevention (CDC), the U.S. Department of Defense (DOD), and the National Aeronautics and Space Administration (NASA). The major components of the MPS were discussed and recent findings summarized. The importance of radiation dosimetry, an essential feature of each MPS investigation, was emphasized. RESULTS:The seven components of the MPS are DOE workers, nuclear weapons test participants, nuclear power plant workers, industrial radiographers, medical radiation workers, nuclear submariners, other U.S. Navy personnel, and radium dial painters. The MPS cohorts include tens of thousands of workers with elevated intakes of alpha particle emitters for which organ-specific doses are determined. Findings to date for chronic radiation exposure suggest that leukemia risk is lower than after acute exposure; lung cancer risk is much lower and there is little difference in risks between men and women; an increase in ischemic heart disease is yet to be seen; esophageal cancer is frequently elevated but not myelodysplastic syndrome; and Parkinson's disease may be associated with radiation exposure. CONCLUSIONS:The MPS has provided provocative insights into the possible range of health effects following low-level chronic radiation exposure. When the 34 MPS cohorts are completed and combined, a powerful evaluation of radiation-effects will be possible. This final article in the MPS special issue summarizes the findings to date and the possibilities for the future. A National Center for Radiation Epidemiology and Biology is envisioned.

The study of One Million U.S. Radiation Workers and Veterans, the Million Person Study (MPS), examines the health consequences, both cancer and non-cancer, of exposure to ionizing radiation received gradually over time. Recently the MPS has focused on mortality patterns from neurological and behavioral conditions, e.g., Parkinson’s disease, Alzheimer’s disease, dementia, and motor neuron disease such as amyotrophic lateral sclerosis. A fuller picture of radiation-related late effects comes from studying both mortality and the occurrence (incidence) of conditions not leading to death. Accordingly, the MPS is identifying neurocognitive diagnoses from fee-for-service insurance claims from the Centers for Medicare and Medicaid Services (CMS), among Medicare beneficiaries beginning in 1999 (the earliest date claims data are available). Linkages to date have identified ∼540,000 workers with available health information. Such linkages provide individual information on important co-factor and confounding variables such as smoking, alcohol consumption, blood pressure, obesity, diabetes and many other health and demographic characteristics. The total person-level set of time-dependent variables, outcomes, organ-specific dose measures, co-factors, and demographics will be massive and much too large to be evaluated with standard software. Thus, development of specialized open-source software designed for large datasets (Colossus) is nearly complete. The wealth of information available from CMS claims data, coupled with individual dose reconstructions, will thus greatly enhance the quality and precision of health evaluations for this new field of low-dose radiation and neurocognitive effects.

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. 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+. 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 https://clinicaltrials.gov/study/NCT03275402 .

Radioactive seed localization (RSL) provides a precise and efficient method for removing non-palpable breast lesions. It has proven to be a valuable addition to breast surgery, improving perioperative logistics and patient satisfaction. This retrospective review examines the lessons learned from a high-volume cancer center’s RSL program after 10 years of practice and over 25 000 cases. We provide an updated model for assessing the patient’s radiation dose from RSL seed implantation and demonstrate the safety of RSL to staff members. Additionally, we emphasize the importance of various aspects of presurgical evaluation, surgical techniques, post-surgical management, and regulatory compliance for a successful RSL program. Notably, the program has reduced radiation exposure for patients and medical staff.