Understanding the health effects of long-term, low-dose ionizing radiation remains a key challenge in radiation protection. This paper reviews the Chinese medical X-ray workers (CMXW) cohort study. Established in the late 1970s, the CMXW cohort is the only nationwide cohort of Chinese medical diagnostic X-ray workers with more than four decades of follow-up. The cohort includes over 27,000 exposed workers and a comparable control group, with several decades of follow-up. Through retrospective dose reconstruction and long-term follow-up, studies from this cohort have consistently demonstrated elevated cancer risks among exposed workers, particularly for leukemia and selected solid cancers. Dose–response analyses based on excess relative risk (ERR) and excess absolute risk (EAR) models show a clear linear association between cumulative dose and cancer risk, with estimates broadly consistent with international cohorts, supporting the linear no-threshold model. As the cohort enters a new phase of follow-up, with expanded outcome assessment and the incorporation of biological samples, it offers new opportunities to integrate molecular epidemiology and explore the mechanisms underlying radiation-related diseases. Future research includes refined exposure assessment, comprehensive evaluation of confounding factors, and emerging frameworks such as the exposome, together with multi-omics approaches, to further understand the health effects of low-dose radiation and support evidence-based radiation protection and public health strategies.
Accurate assessment of health risks from chronic low-dose ionizing radiation is limited by large uncertainties, largely due to the absence of reliable individual exposure data, particularly for long-term internal exposure. In vivo counting provides a direct and non-invasive approach for quantifying trace-level radionuclides retained in the human body and supporting retrospective exposure assessment. The Trace-level RAdionuclides in vivo Counting Experiment (TRACE) is a prospective study aimed at developing experimental methodologies relevant to low-dose radiation exposure. The current focus is on cumulative radon (222Rn) exposure through in vivo measurement of 210Pb activity in the skull. With a half-life of 22.3 years and bone-seeking behavior, 210Pb accumulates in skeletal tissue over decades and can serve as an indicator of long-term radon intake. Practical implementation is challenged by extremely low signal levels, subject-dependent efficiency calibration, and uncertainties in internal dose modeling. To address these issues, TRACE has made progress in three aspects. A small-scale shielding prototype has been constructed to validate background suppression strategies, demonstrating a background reduction of approximately two orders of magnitude. In parallel, a source-free efficiency calibration method using CT-derived computational skull phantoms shows agreement with experimental measurements within ∼4%. In addition, a respiratory deposition model incorporating anatomical and physiological parameters representative of the Chinese population has been established to improve internal dose assessment. By improving the reliability of retrospective exposure assessment at the individual level, TRACE aims to support health-oriented risk evaluation and efforts to promote health and well-being.
Objective To compare the dosimetric differences among dynamic conformal radiotherapy (DCRT), dynamic conformal arc (DCA), volumetric modulated arc therapy (VMAT), and intensity-modulated radiotherapy (IMRT) in the treatment of early-stage non-small cell lung cancer (NSCLC), and to explore the feasibility of using the Universal Survival Curve (USC) model to predict biological performance. Methods Thirty patients with NSCLC who underwent SBRT treatment were retrospectively selected, and the physical dosimetric parameters of four radiotherapy plans were designed and analyzed. Based on the dose distribution of each plan, the LQ and the USC model were respectively applied to calculate the biologically effective dose and related indicators. Results In terms of dosimetry, the VMAT plan demonstrated relatively favorable target conformity (CI: 0.89). The VMAT plan demonstrated superior sparing of high-dose regions in the lung, whereas IMRT was more effective in reducing whol -lung and ipsilateral lung low-dose volumes (V5 and V10), but with higher monitor units compared to VMAT. In terms of radiobiological predictions, systematic differences were observed between the LQ and USC models, with results from the LQ model generally being higher than those from the USC model. Tumor control probability (TCP) for all plans exceeded 97%, with the VMAT plan showing the highest TCP value and the lowest normal tissue complication probability (NTCP) value among all plans. Conclusion VMAT may offer advantages in improving target conformity, and OAR protection, while IMRT showed no significant differences in most OAR parameters, serving as a suitable alternative. The USC model extends the LQ model into the high-dose region, offering a new tool for SBRT biological assessment.
Radiotherapy remains a fundamental modality in cancer treatment; however, its clinical efficacy is frequently constrained by heterogeneous tumor radiosensitivity and treatment-associated toxicities. Although the supporting evidence remains largely preliminary, vitamins—as readily accessible micronutrients—have been hypothesized to function as potential radiosensitizers. To address this gap, this review systematically examines the proposed mechanisms through which vitamins may modulate radiotherapy responses, including the modulation of oxidative stress, DNA damage repair, cell cycle regulation, and remodeling of the tumor immune microenvironment. Furthermore, this review integrates existing preclinical data and currently sparse, early-phase clinical evidence, explores key translational challenges including dose optimization and inter-individual variability, and outlines future interdisciplinary research directions, so as to inform the rational design and rigorous evaluation of vitamin-based radiosensitization strategies in precision oncology.
Objective To investigate the radioprotective effects of N-oxalyl-d-phenylalanine (NOFD) against radiation-induced lung injury (RILI), and to determine whether hypoxia inducible factor (HIF)-related regulation contributes to its protective action. Methods Male C57BL/6 mice were randomized into four groups: Control (non-irradiated + normal saline), IR + NS (irradiated + normal saline), IR + NOFD (irradiated + 5 mg/kg NOFD), and IR + Amifostine (irradiated + 5 mg/kg Amifostine) (n=5). The in vivo radioprotective potential of NOFD was evaluated in a murine RILI model exposed to a single dose of 15 Gy thoracic X-ray irradiation with head and abdomen shielded. Body weight was recorded daily and histological damage was examined by hematoxylin and eosin (H&E) staining. Oxidative stress markers, including malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT), were measured using corresponding biochemical assay kits. Inflammatory and profibrotic cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and transforming growth factor-beta 1 (TGF-β1), as well as HIF-related regulatory factors, including hypoxia-inducible factor 1 alpha (HIF1α), prolyl hydroxylase domain protein (PHD), and vascular endothelial growth factor A (VEGF-A), were assessed using ELISA kits. To investigate the role of HIF-related regulation, HIF1A- and HIF2A-deficient human bronchial epithelial BEAS-2B cell lines were generated using CRISPR-Cas9. Intracellular oxidation-sensitive fluorescence, γ-H2AX signal, and cell-cycle distribution were evaluated in irradiated wild-type cells, NOFD-treated wild-type cells, and HIF-deficient cells using immunofluorescence and flow cytometry. mRNA expression of HIF-related and functionally relevant genes was further examined by quantitative real-time PCR (qPCR). Results In a murine RILI model, NOFD effectively alleviated IR-induced body weight loss and lung histopathological damage including alveolar destruction and inflammatory infiltration. Compared with the IR + NS group, NOFD treatment increased SOD and CAT activities (2.11- and 3.42-fold, respectively) and reduced MDA level by 67.60%. NOFD also restored HIF-related regulatory factors in irradiated lung tissues, including a 2.96-fold upregulation of PHD, which reduced HIF1α accumulation by 24.58% and suppressed VEGF-A overexpression by 52.02%. Additionally, NOFD attenuated inflammatory and profibrotic cytokines (TNF-α, IL-1β, TGF-β1). In irradiated bronchial epithelial cells, NOFD pretreatment significantly reduced γ-H2AX signal by 63.72% and ROS accumulation by 51.46% compared to irradiated wild-type BEAS-2B cells. HIF1A-deficient cells showed greater sensitivity than HIF2A-deficient cells, with higher γ-H2AX (1.29-fold) and ROS (2.34-fold) levels relative to irradiated wild-type cells. NOFD reduced γ-H2AX signal and intracellular oxidation-sensitive fluorescence in irradiated wild-type BEAS-2B cells, whereas HIF1A- or HIF2A-deficient cells showed increased radiosensitivity and enhanced radiation-associated G2/M accumulation. Under basal conditions, NOFD increased HO1 and P53 expression by approximately 1.38-fold and 2.83-fold, respectively, while reducing BNIP3 expression by about 25.42%. Conclusion NOFD attenuates radiation-induced lung injury at both the tissue and cellular levels. These findings support that HIF-related regulation is required for NOFD-mediated radioprotection and suggest that NOFD may serve as a potential candidate for the mitigation of RILI.
Objective: To investigate the clinical impact of plan complexity on local progression-free survival (LPFS) and overall survival (OS) in limited-stage small cell lung cancer (LS-SCLC) patients treated with hyper-fractionated radiotherapy.
Objective: To investigate the role of integrin beta-1 (Itgb1) in radiation-induced tissue injury and elucidate its underlying molecular mechanisms. Methods: Differentially expressed genes associated with radiation injury were identified from the Gene Expression Omnibus (GEO) microarray database through bioinformatics analysis, followed by enrichment analysis to determine core hub genes. In vitro, Itgb1 was silenced using siRNA transfection in human chronic myeloid leukemia K562 and mouse alveolar epithelial MLE-12 cells. Protein expression was assessed by Western blot, while cell proliferation, apoptosis, and reactive oxygen species (ROS) levels were quantified by flow cytometry following Itgb1 inhibition. In vivo, C57BL/6 mice were divided into 4 experimental groups (n = 5 per group): Control (intraperitoneal injection of PBS without irradiation), RGD (intraperitoneal injection of RGD 10 mg/kg without irradiation), IR + PBS (8 Gy 60Co γ-ray total body irradiation with PBS), and IR + RGD (intraperitoneal injection of RGD 10 mg/kg, 2 h prior to 8 Gy 60Co γ-ray total body irradiation). Bronchoalveolar lavage fluid (BALF) was collected for macrophage analysis. Lung and intestine tissues were subjected to hematoxylin-eosin (H&E) staining and immunofluorescence (IF) examination. Peripheral blood samples were analyzed to evaluate hematopoietic function. Results: Bioinformatics analysis identified Itgb1 as a hub gene in radiation-induced injury. Western blot analysis demonstrated significant upregulation of Itgb1 protein following irradiation. In K562 cells, Itgb1 expression peaked at 12 h post-irradiation (t = 3.07, P < 0.01) and declined by 24 h, whereas MLE-12 cells exhibited sustained elevation at both time points (t = 10.44, P < 0.0001). Itgb1 silencing significantly exacerbated radiation-induced cellular damage. In K562 cells, knockdown reduced S-phase proliferation from 52.49% to 36.41% (t = 9.64, P < 0.01), increased apoptosis (t = 11.36, P < 0.001), and elevated ROS levels (t = 3.62, P < 0.05). Comparable effects were observed in MLE-12 cells: reduced proliferation (46.82% to 37.98%, t = 12.78, P < 0.0001), enhanced apoptosis (t = 10.16, P < 0.0001), and increased ROS (t = 5.58, P < 0.0001). In vivo, Itgb1 inhibition aggravated radiation-induced pulmonary, intestinal and hematopoietic injuries, characterized by increased inflammatory infiltration, alveolar septal thickening, and decreased peripheral blood cell counts (t = 2.34, P < 0.01). These findings indicate that Itgb1 functions as a protective factor against radiation injury. Conclusions: This study elucidates Itgb1 critical radioprotective role, where compensatory upregulation constitutes an endogenous defense mechanism, while its deficiency exacerbates injury through amplified apoptosis and inflammation, highlighting its clinical utility as a therapeutic target.
This study evaluates the radiation protection status and regulatory compliance (BAER Act-2012, NSRC Rules-1997, and Regulatory Guides) in 153 diagnostic X-ray facilities across four different districts (Chandpur, Dinajpur, Pirojpur, and Tangail) of Bangladesh. The results show that 71% facilities are licensed, 66% have certified RCOs, 93% possesses personal protective equipment, 78% have appointed qualified radiation workers, 79% workers have personal dosimeters, and near 92% have the required wall thickness in the X-ray room. Proper shielding is observed at 73% entrance doors and in 76% control rooms. The shortcomings are found in the standard room size requirement (25%) and the presence of warning signs (29%). Radiation dose rates in the control room are within the permissible limit in most facilities (72%), but not satisfactory at the entrance door (22%). Chandpur district has a better radiation safety structure than the other three districts, where Pirojpur district stands in the bottom position. Facilities that have a CT scan with a conventional X-ray show better compliance compared to only conventional X-ray and dental X-ray facilities. Comparative study with the regulatory survey, which was conducted in 2000, demonstrates significant improvements in radiation safety infrastructure in these districts. These findings represent significant progress and also highlight gaps in the radiation safety structure in rural areas of the country. The Regulatory Authority should focus on improvement in the areas lacking to ensure a proper radiation safety structure in Bangladesh.
As one of the primary modalities for cancer treatment, radiotherapy (RT) utilizes high-energy radiation to eradicate cancer cells or inhibit tumor growth and is widely employed in clinical practice. However, while targeting malignant cells, radiation can also cause unintended damage to surrounding healthy tissues, leading to serious complications that adversely affect patient prognosis and quality of life. In recent years, hydrogels have emerged as promising adjuvant systems for RT due to their tunable physicochemical properties, excellent biocompatibility, and capacity for multifunctional integration. This review systematically summarizes recent advances in hydrogel-based platforms designed for radiation protection and therapy enhancement, focusing on how material composition and morphological design enable localized modulation of radiation dose, proactive prevention of side effects, and coordinated intervention in the tumor microenvironment. The review aims to provide a comprehensive resource for understanding the multifunctional roles of hydrogels in RT and to explore their potential pathways toward clinical translation, with the goal of advancing precise, low-toxicity, and personalized radiotherapy.
Objective: To determine the activity concentrations of naturally occurring radionuclides 238U and 232Th in commonly consumed foods from East China and to evaluate the associated dietary exposure and potential radiological health risk to the general population. Methods: A total of 61 food items belonging to 10 major dietary categories were collected from local markets in a region of East China, pretreated by drying, homogenization, and acid digestion, and analyzed for 238U and 232Th using inductively coupled plasma mass spectrometry (ICP-MS). Activity concentrations were calculated and used to assess distribution patterns and inter-element correlations across food groups. The annual committed effective dose from dietary intake was estimated based on measured concentrations and regional consumption data. Results: Both 238U and 232Th were widely detected in the analyzed food samples, with activity concentrations ranging from 11 to 4514 and 7 to 1649 mBq/kg (dry weight), respectively. A significant positive correlation between the two radionuclides indicates a common natural origin. Clear food-type dependence was observed, with vegetables and legumes showing relatively higher 238U levels and elevated 238U/232Th ratios, while aquatic products and fruits exhibited lower ratios. The annual committed effective doses from dietary intake were estimated at 0.54 μSv/year for 238U and 1.90 μSv/year for 232Th, which are several orders of magnitude below the recommended public exposure limit of 1 mSv/year. Conclusion: The results provide baseline information on the occurrence of naturally occurring radionuclides in commonly consumed foods and indicate that current dietary intake levels pose negligible radiological risk to the general population. These findings support the continued monitoring of natural radionuclides in food to ensure food safety and public health protection.
Objective To investigate the role of integrin beta-1 (Itgb1) in radiation-induced tissue injury and elucidate its underlying molecular mechanisms. Methods Differentially expressed genes associated with radiation injury were identified from the Gene Expression Omnibus (GEO) microarray database through bioinformatics analysis, followed by enrichment analysis to determine core hub genes. In vitro, Itgb1 was silenced using siRNA transfection in human chronic myeloid leukemia (K562) and mouse alveolar epithelial (MLE-12) cells. Protein expression was assessed by Western blot, while cell proliferation, apoptosis, and reactive oxygen species (ROS) levels were quantified by flow cytometry following Itgb1 inhibition. In vivo, C57BL/6 mice (n=5 per group) were divided into 4 experimental groups: Control (intraperitoneal injection of PBS without irradiation), RGD (intraperitoneal injection of RGD 10 mg/kg without irradiation), IR+PBS (8 Gy 60Co γ-ray total body irradiation with PBS), and IR+RGD (intraperitoneal injection of RGD 10 mg/kg, 2 h prior to 8 Gy 60Co γ-ray total body irradiation). Bronchoalveolar lavage fluid (BALF) was collected for macrophage analysis. Lung and intestine tissues were subjected to hematoxylin-eosin (H&E) staining and immunofluorescence (IF) examination. Peripheral blood samples were analyzed to evaluate hematopoietic function. Results Bioinformatics analysis identified Itgb1 as a hub gene in radiation-induced injury. Western blot analysis demonstrated significant upregulation of Itgb1 protein following irradiation. In K562 cells, Itgb1 expression peaked at 12 h post-irradiation (t= 3.07, P < 0.01) and declined by 24 h, whereas MLE-12 cells exhibited sustained elevation at both time points (t = 10.44, P < 0.0001). Itgb1 silencing significantly exacerbated radiation-induced cellular damage. In K562 cells, knockdown reduced S-phase proliferation from 52.49% to 36.41% (t = 9.64, P < 0.01), increased apoptosis (t = 11.36, P < 0.001), and elevated ROS levels (t =3.62, P < 0.05). Comparable effects were observed in MLE-12 cells: reduced proliferation (46.82% to 37.98%, t = 12.78, P < 0.0001), enhanced apoptosis (t = 10.16, P < 0.0001), and increased ROS (t = 5.58, P < 0.0001). In vivo, Itgb1 inhibition aggravated radiation-induced pulmonary, intestinal and hematopoietic injuries, characterized by increased inflammatory infiltration, alveolar septal thickening, and decreased peripheral blood cell counts (t = 2.34, P < 0.01). These findings indicate that Itgb1 functions as a protective factor against radiation injury. Conclusions This study elucidates Itgb1 critical radioprotective role, where compensatory upregulation constitutes an endogenous defense mechanism, while its deficiency exacerbates injury through amplified apoptosis and inflammation, highlighting its clinical utility as a therapeutic target.
Objective To assess the knowledge, attitudes, and practices (KAP) of radiology and operating room personnel regarding radiation protection and safety. Methods An institution-based cross-sectional study was conducted to assess the KAP of Yemeni staff members in radiology departments and operating rooms representing various public and private institutions throughout Yemeni cities, the data collection was carried out via a Google form-based questionnaire disseminated to 315 individuals. A total of 256 valid responses were received with response rate of 81.27%. Results The results indicated inadequate knowledge with an overall mean score of (3.547/10). On the other hand, the respondents had positive attitudes (3.895/5), and moderate adherence to practice (3.406/5) toward radiation protection and safety. There were no significant differences in knowledge and practices scores by sex, however, while the attitude dimension score exhibited statistically significant differences (U=6878, P<0.05). Additionally, significant differences were observed between the occupations (H= 28.949, P<0.05) and education levels of the respondents (H=11.137, P<0.05). Furthermore, the findings highlighted the positive impact of educational interventions (radiation safety training/lectures) on the total knowledge, attitude and practice scores (all P<0.05) regarding radiation protection. The respondents' attitudes score correlated moderately with their practice compliance score connected to radiation protection (r=0.48, P<0.05). Moreover, the respondents addressed the shortage of radiation protection equipment (66.02%), and policies/management support (64.45%), as the most common barriers that limit their compliance with radiation protection and safety practices. In addition, they recommended providing sufficient resources (81.25%), establishing a radiation safety culture (76.95%), and providing periodic training programs to improve radiation protection practices (69.92%). These outcomes emphasize the necessity of specific educational intervention and organizational dedication to enhance radiation safety culture in Yemen. Conclusion The findings highlight the critical need for effective management support, sustained institutional commitment, and targeted educational actions at the university level and through ongoing training to improve radiation protection awareness and behaviours among healthcare workers in medical radiation environments.
Objective To investigate nuclear and radiation risk perceptions and attitudes toward nuclear energy development among nuclear emergency reserve personnel (NERP), in order to enhance their comprehensive nuclear emergency response capabilities. Methods An on-site survey was conducted on 1513 NERP from provincial-level institutions and those within 50 km of nuclear power plants in Liaoning, Jiangsu, Shandong, and Hainan provinces, China. Data were collected from www.wjx.cn, a widely used online survey platform in China. Intergroup comparisons of scores or ratings were conducted using the Kruskal-Wallis H test. Associations between risk-benefit and trust ratings, knowledge awareness and sociodemographic characteristics, and acceptance and relevant factors were analyzed using Spearman's correlation, linear regression and logistic regression, respectively. The priority of influencing factors was determined using classification and regression tree (CART) analysis. Results A total of 49.06%‒75.43% of NERP possessed nuclear and radiation knowledge. Higher educational levels and professional titles were significantly positively correlated with awareness rates of nuclear and radiation knowledge. Compared with physicians, nurses, management service personnel , and firefighters , demonstrated significantly lower awareness rates (β =−12.39% ∼ −4.59%, P<0.05). Support for local nuclear power plant construction was significantly lower than that for national projects. Acceptance of the national and local nuclear power plant construction was associated with gender, nuclear radiation knowledge, risk and benefit assessments, and trust (OR = 0.14−3.21, P < 0.05). Benefit assessment was the primary factor for national nuclear power plant construction, whereas risk assessment was the key determinant for local projects. Conclusions Inadequate nuclear and radiation knowledge and the "not in my backyard (NIMBY)" phenomenon among NERP are notable concerns. Targeted and systematic knowledge training and regular emergency drills are essential for NERP. Public communication should be strengthened to clarify nuclear energy risks and benefits, enhance trust in official information, and increase its proportion in public information.
Objective: To develop an artificial intelligence (AI) driven plan tradeoff decision making assistant for radiation oncologists. Methods: A user interface (UI) was developed to integrate the assistant with the treatment planning system to facilitate prescription decision process. The assistant is powered by a machine learning core which was trained to learn the balance between planning target volume (PTV) coverage and organs-at-risk (OAR) sparing. A group of 98 pancreatic stereotactic body radiation therapy (SBRT) cases were retrospectively included for this study. The clinical plan's PTV coverage was compared against the model predicted value. A 10-fold cross validation was performed for all cases. The comparison was further analyzed in detail for three attending physicians. Cases with large discrepancy were identified and analyzed, and a replan was created to evaluate the achievability of the prediction. Results: The clinical plan PTV V100% was (87.7 ± 14.5)% while the model predicted value was (90.5 ± 9.6)%. Model agreement discrepancy was observed between attending physicians. Among all 98 cases, 9 were identified with large variation from the model prediction. For the replans, an average of 15.3% improvement was achieved over the original clinical plan, while OARs constrains were met. Conclusions: The assistant's decision provides decent plan quality guidance for prescription drafting. It could provide valuable input prior to treatment planning and save valuable dosimetrist team and radiation oncologist effort. It could further provide valuable insight for resident education and training.
Objective To explore the imaging biomarkers obtained from baseline multi-modality imaging PET/ CT before metastasis-directed therapy (MDT), which could offer early response prediction before MDT treatment, optimizing patient management and improving outcomes. Methods The study analyzed a multi-institutional cohort of 118 patients with oligometastatic castration-sensitive prostate cancer (omCSPC), including 34 from Johns Hopkins Hospital (JHH) and 84 from Baskent University (BU), all treated with stereotactic ablative radiation therapy SABR-MDT. Before MDT, all patients underwent PSMA PET and CT imaging. For radiomics analysis, the gross tumor volume (GTV) was defined as zone 1, with an additional 5 mm peritumoral expansion designated as zone 2. From these regions, 1308 radiomics features were extracted. Feature selection was performed using a mutual information function, identifying the five most informative radiomics features from prostate-specific membrane antigen (PSMA) PET and CT. These were combined with five key clinical parameters—age, Gleason score, total number of lesions, number of untreated lesions, ADT, and pre-MDT prostate-specific antigen (PSA)—as model inputs. Multiple machine-learning algorithms, including random forest, decision tree, support vector machine, and naïve Bayes, were applied to predict 2-year metastasis-free survival (MFS). Model performance was evaluated using both leave-one-out and cross-institution validation. Results In a leave-one-out test with 93 patients, random forest achieved 78% accuracy and an AUC of 0.80 in predicting 2-year MFS. In cross-institution validation with 61 BU and 32 JHH patients, random forest correctly predicted 2-year MFS for 69% and 71% of patients, with AUC values of 0.71 and 0.73, respectively. Kaplan Meier curve comparison shows statistically significant separation between “rapid progressors” and “non-rapid progressors” patients stratified by the model in both leave one out and cross-institution validation tests. Conclusion This study provides evidence that pre-treatment multi-modality imaging biomarkers derived from PSMA PET and CT can serve as valuable predictors of metastasis-free survival (MFS) in patients with omCSPC.
Within the United Nations Sustainable Development Goals (UN SDGs), health and well-being are one of the most important goals. This perspective highlights recent institutional progress at Korea Institute of Radiological and Medical Sciences (KIRAMS) that bridges scientific innovation, clinical application, and sustainability, which are aligned with the global vision of the UN SDGs. The key activities include long-term research on second primary cancers to strengthen survivorship care, the clinical application of targeted alpha-particle therapy using Actinium-225 for advanced neuroendocrine and prostate cancers, and the expansion of radiopharmaceutical research and development. These activities demonstrate how advanced radiation technologies can be translated into tangible clinical benefits while enhancing patient safety and long-term outcomes. In addition, KIRAMS has leveraged its expertise in radiation emergency medicine to contribute to broader public health responses. Collectively, these efforts illustrate how a mission-driven medical institution can align specialized radiation medicine with global sustainability agendas and strengthen international networks.
Objective To identify risk factors for post-radiation xerostomia and to evaluate the tolerance to doses administered to the parotid gland in patients with nasopharyngeal carcinoma (NPC). Methods A total of 462 patients with NPC who received radiotherapy at Nanfang Hospital of Southern Medical University and Sichuan Cancer Hospital from 2012 to 2016 were retrospectively analyzed. Xerostomia was diagnosed according to the Radiation Therapy and Oncology Group (RTOG) grade. Medcalc software and SPSS software were used for statistical analysis, and MATLAB and R software was used for modeling. Results The cut-off values for Dmean (the average dose of parotid), Dmean-L (the average dose of left parotid) and D50-R (dose received at 50% volume of right parotid) were 26.00, 28.30 and 23.93 Gy, above which the risk of long-time xerostomia occurs is increased (P < 0.05). D50, D50-L, D50-R, Dmean, Dmean-L and Dmean-R were 28.66, 23.12, 29.04, 28.00, 28.30 and 35.55 Gy, respectively, but the results showed that this dose was not associated with highest xerostomia grade (HXG) (P > 0.05). The relevant factors were independent risk factors for the development of xerostomia, the same was true for age, T stage, and D-PTV (dose of PTV). Using patient's gender, radiation treatment, number of radiotherapy sessions, T stage, TNM stage, Dmean and D50 (dose received at 50% volume of the parotid glands) to established a prediction model to predict HXG and long-term xerostomia grading (LTG), the results indicated that Training showed R = 0.82. The independent risk factors were included to establish the nomogram prediction model. The results showed that the C-index was 0.671. Conclusion It is feasible to establish a neural network model or a nomogram prediction model using parotid dose parameters to predict the incidence of radiation-induced xerostomia.
Objective To re-assess the risk of radon-induced lung cancer with more recent and significantly reduced tobacco smoking rates in Canada. Methods Based on the radon distribution characteristics obtained from the cross-Canada radon survey and with the EPA/BEIR VI risk model as well as the same model parameters used in previous study, Canadian population risk for radon-induced lung cancer was re-assessed with Canadian age-specific smoking prevalence data of ever smokers in 2022 and Canadian age-specific mortality rates averaged over five years from 2019 to 2022. Results In the past 20 years from 2002 to 2022, the rates of ever-smokers among Canadians aged 15 and older dropped by 44% for males and by 42% for females. As a result, the baseline risks of lung cancer decreased by 14% for males and 10% for females. The re-evaluation indicates that 12% of lung cancer deaths among Canadian males and 13% of lung cancer deaths among Canadian females are attributable to indoor radon exposure, significantly lower than 16% of radon-induced lung cancer deaths among Canadians as estimated previously. Conclusions This re-assessment updated the estimates of radon-induced lung cancer in Canada. The study estimated that the success of tobacco control program over time (more than 40% reduction in percentage of ever-smokers in Canadian population in the past two decades) could result in 4% less radon-induced lung cancer deaths in males and 3% less in females.
Objective To investigate the time-dependent progression of cranial radiation-induced testicular injury in mice, focusing on apoptotic pathways and brain-testis axis involvement. Methods Male mice were randomly divided into sham irradiation group (sham) and cranial irradiation group (IR) with 36 mice in each group. The IR group received a single dose of 20 Gy cranial X-ray irradiation, while peripheral organs were shielded. Assessments of body weight, testis weight, and sperm parameters were conducted at 1, 2, and 4 weeks post-irradiation. Histological changes and apoptosis were evaluated via H&E staining and TUNEL assay, respectively. Cell-specific markers SOX9, WT1, SYCP3 and PRND were quantified by qRT-PCR, while apoptotic proteins Bcl-2, Bax and Cleaved-caspase 3 were examined by Western blot. Serum levels of brain injury biomarkers NSE and S100B were measured using ELISA. Results Compared with sham group, IR mice displayed distinct, time-dependent testicular and systemic alterations. At 1 week post-irradiation, no obvious testicular structural damage was observed, but significant reductions in body and testis weight were accompanied by elevated serum NSE (142.1 ± 16.5 vs. 102.1 ± 3.6, t = 7.1, P < 0.05) and S100B ( 178.2 ± 23.8 vs. 123.9 ± 11.5, t = 6.2, P < 0.05). At 2 weeks post-irradiation, disorganized spermatogonial stem cells (SSCs), downregulated SYCP3 and PRND expression, and a marked increase in sperm abnormalities were evident (52.45 ± 3.35 vs. 33.46±6.05, t = 7.77, P < 0.05), alongside sustained weight loss and persistent elevation of NSE (128.6±3.2 vs.110.6 ± 2.8, t =12.8 , P < 0.05) and S100B levels (163.1 ± 5.9 vs. 131.5 ± 10.9, t = 7.8, P < 0.05). At 4 weeks post-irradiation, severe testicular atrophy manifested, characterized by reduced seminiferous tubule diameter, further increased sperm abnormalities (64.61 ± 8.18 vs. 42.64 ± 3.13 , t = 7.10, P < 0.05), decreased sperm counts (vs. 3.08 ± 1.36 vs. 8.55 ± 2.05, t = 6.30, P < 0.05), upregulated Cleaved-caspase 3 protein expression (1.75 ± 0.15 vs. 1.00 ± 0.21, t = 7.10, P < 0.05), TUNEL-positive cells localized to spermatogonial stem cells (SSCs) niches. Concurrently, SOX9 (2.12 ± 0.96 vs. 1.00 ± 0.31) and WT1 (2.51 ± 1.34 vs. 1.00 ± 0.57) mRNA levels were significantly upregulated (t = 2.72, 2.55, P < 0.05). Persistent reductions in body and testis weight, as well as sustained elevations in NSE and S100B, were observed throughout the study. Conclusion Cranial radiation induces progressive, time-dependent testicular injury in mice via mechanisms mediated by the brain-testis axis, primarily targeting SSCs for apoptosis. These findings identify the brain-testis axis as a novel therapeutic target for mitigating reproductive toxicity in male patients undergoing cranial radiotherapy.
