Long-Term Results of a Phase II Clinical Trial of Radiation Volume and Dose De-intensification Following Transoral Robotic Surgery and Neck Dissection for Human Papillomavirus-Associated Oropharyngeal Squamous Cell Carcinoma.

Objective.Computed tomography (CT) is an indispensable tool in clinical diagnosis. However, it involves non-negligible risks associated with exposure to ionizing radiation. Accurate radiation dose assessment is essential for quantifying radiation-related risks. To enable the accurate evaluation of radiation doses in Chinese patients undergoing CT examinations, we aim to develop a Chinese adult mesh phantom library based on the Chinese population.Approach.Firstly, we analyze the relationships between body size and anthropometric parameters in the Chinese adult population. Secondly, anatomical contours are obtained from clinical images using both automated and manual image segmentation algorithms, and these contours are then used to construct personalized mesh phantoms. Finally, organ doses are simulated using an in-house Geant4-based CT simulation software to investigate their correlations with body size.Main results.Compared with the Chinese anatomical reference data, the organ masses of the normal-weight phantom show discrepancies of approximately 10%. At the commonly used tube voltage of 120 kVp for clinical abdominal CT examinations, the maximum dose differences among male phantoms with different body sizes were 5.04 mGy for the liver, 8.49 mGy for the kidneys, 8.21 mGy for the spleen, and 7.92 mGy for the pancreas. The corresponding maximum dose differences were 8.48 mGy for the liver, 7.33 mGy for the kidneys, 6.73 mGy for the stomach, and 7.14 mGy for the pancreas for female phantoms.Significance.We establish a cohort of mesh phantoms that accurately represent Chinese adults according to the linear regression relationship between body size and human parameters. The observed differences in organ doses among different phantoms further highlight the importance of developing individualized computational phantoms for Chinese adults.

ObjectivesTo evaluate the application of different tube voltages and image-reconstruction algorithms in paranasal-sinus computed tomography (CT) and optimizes the scanning protocols for paranasal-sinus CT while balancing between image quality and radiation dose.MethodsNinety patients were randomly divided into three groups (A, B, and C). Group A used conventional scanning parameters: tube voltage of 120 kVp, tube current uDose level 1, and the Karl iterative reconstruction algorithm. Groups B and C used tube voltages of 100 and 80 kVp, respectively, and tube current uDose level 1. The Karl iterative reconstruction algorithm and artificial intelligence iterative reconstruction (AIIR) algorithm were used. Optimal image reconstruction noise levels were selected for each group, and the image quality and radiation doses of the best images were statistically analyzed.ResultsThe best image reconstruction noise levels for Groups A, B, and C were Karl level 5, AIIR level 5, and AIIR level 4, respectively. The signal-to-noise ratio, contrast-to-noise ratio, figure of merit, and subjective score values of the images in Groups B (AIIR level 5) and C (AIIR level 4) were higher than those in Group A (Karl level 5). The patients from Groups B and C had the CT dose-index volume, dose-length product, and size-specific dose estimate based on the water-equivalent diameter that were 68.86%, 71.76%, 69.84%, 84.39%, 85.95%, and 85.50% lower, respectively, than those of Group A (P < 0.001).ConclusionsA low tube voltage combined with the AIIR algorithm effectively improves image quality and decreases the radiation doses for patients undergoing paranasal-sinus CT. The optimal parameters for paranasal-sinus CT are 80 kVp, uDose level 1, and AIIR level 4.

Radiation protective drapes are sometimes placed on the patient during fluoroscopically guided procedures to reduce scattered radiation to medical personnel. However, there are concerns that these drapes may increase patient radiation dose due to backscattered radiation. In this study, thermoluminescent dosimeters (TLDs) were used to quantify backscattered radiation from three protective drapes, on top of and at different depths, in a polymethyl methacrylate (PMMA phantom). Monte Carlo simulations were also performed to theoretically quantify backscattered radiation from lead. The results showed that the backscattered radiation varied with the material of the drape and was less than a factor of 0.001 of the radiation dose from the primary radiation beam (including backscatter from the PMMA phantom). This minor increase in patient radiation dose does not need to be considered if the use of such drapes has been justified from an occupational radiation protection perspective.

Study Design: Retrospective review of consecutively, prospectively enrolled patients. Objective: To evaluate the impact of navigation for percutaneous pedicle screw fixation (PPSF) in lateral decubitus single position surgery (L-SPS) on operative efficiency and safety. Summary of Background Data: Posterior instrumentation is increasingly being performed in the lateral decubitus position. In L-SPS, PPSF is most often performed using a fluoroscopic technique. However, the utilisation of computer-assisted navigation enables simultaneous anterior exposure to be performed and limits radiation exposure to operating staff. Methods: L-SPS patients involving anterior lumbar interbody fusion (ALIF) with or without additional lateral lumbar interbody fusion (LLIF) were divided according to the PPSF technique. “Nav” patients had PPSF utilising computer navigation with simultaneous anterior exposure. “Fluoro” patients had PPSF under fluoroscopy performed either before or following anterior exposure. Results: Two hundred seventy-three patients were included, 187 “Nav” and 86 “Fluoro” patients. In total, 1036 pedicle screws were inserted, 708 navigated, and 328 fluoroscopic. Mean posterior levels (1.89 vs . 1.91, P = 0.910) and ALIF levels fused (1.17 vs . 1.13, P = 0.435) were similar. Mean operative time was significantly reduced in the “Nav” group (116.83 vs. 148.54 min, P &lt; 0.001; 21.3% reduction). Estimated blood loss (258.28 vs . 188.53 mL, P = 0.066) and length of stay (2.33 vs. 2.24 d, P = 0.730) were not statistically significant. Patient radiation dose (91.11 vs. 46.47 mGy, P &lt; 0.001) and radiation time (132.82 vs. 117.20 seconds, P &lt; 0.001) were higher among “Nav” patients. Intraoperative complications (4.3% vs. 2.3%, P = 0.425) including vascular injury (2.1% vs. 0.0%, P = 0.172) and instrumentation-related complications (2.1% vs. 2.3%, P = 0.922) were not statistically significant. Postoperative complications (12.8% vs. 20.9%, P = 0.112) and reoperation rates within 90 days (3.2% vs. 7.0%, P = 0.158) were not statistically significant. No posterior instrumentation-related revisions were observed among “Nav” patients, compared with 2.3% of “Fluoro” patients ( P = 0.036). Conclusions: Simultaneously navigating posterior instrumentation during anterior exposure in L-SPS improves operative efficiency and may reduce instrumentation-related complications without compromising safety.

The advancement of X-ray computed tomography coronary angiography (CTCA) has facilitated the acquisition of dynamic CTCA images within a single cardiac cycle, achieving a very low radiation dose while maintaining acceptable image quality. This study aimed to evaluate the radiation dose and cancer risk in patients who underwent computed tomography coronary angiography ( CTCA). The radiation data and related parameters were analyzed in 232 patients who underwent CTCA at a single hospital. Dose data were retrospectively extracted from the hospital information system using the DoseWatch software. The effective dose (E) values were determined using CT-expo 2.5 software, while the Lifetime Attributable Risk (LAR) was estimated using sex- and age-specific risk coefficients provided by the International Commission on Radiological Protection (ICRP). The reported doses in CTCA were as follows: median (interquartile range) CT dose-length product (DLP) and volume CT dose index (CTDI vol ), which were 268 mGy cm (100–492) and 2.92 mGy (1.57–20.01), respectively, while the E was 5.21 mSv (2.16–10.7). The LAR values (per 10 6 ) ranged between 58–426 and 260–1025 for male and female patients, respectively. The CTCA doses obtained using a 256-row scanner with dual-energy technology were comparable to the previously reported values, demonstrating significantly improved dose performance through the incorporation of dose reduction features of modern CT scanners. However, risk-benefit analyses should be conducted before CTCA examinations, particularly for young female patients, to mitigate the associated cancer risk.

Impact of body-mass-index (BMI) on effective dose of whole-body [18F] fluorodeoxyglucose PET/CT examinations.

Low keV virtual monoenergetic (VME) images are effective in enhancing vessel opacification but require dual-energy CT (DECT), limiting widespread clinical use. Recent advancements in deep learning (DL) enable the generation of VME images from single-energy CT (SECT). However, the performance of the methods has not been evaluated in any clinical use case. The purpose of this work was to assess both objective and subjective image quality of deep learning-based VME images derived from heterogeneous SECT data for pulmonary angiography. In this retrospective study, 52 sets of SECT pulmonary angiography images were processed using a deep learning method to estimate material basis images. 40keV VME images were generated from heterogeneous SECT data using a pretrained physics-constrained Deep-En-Chroma DL model. Two thoracic radiologists, blinded to the image reconstruction method, evaluated pulmonary vessel opacification and overall image quality on DL-VME and SECT images using 5-point Likert scales. Objective image quality was assessed by measuring enhanced vessel contrast and contrast-to-noise ratio (CNR). Statistical analysis was performed using paired t tests and Mann-Whitney U tests. Compared with SECT, DL-VME images demonstrated significantly higher subjective image quality score and vessel opacification score ( P ≤0.008). DL-VME yielded a higher average contrast for emboli (1085 vs. 331HU, P <0.001) and improved CNR (17.8 vs. 11.1, P <0.001). Results of subgroup analysis indicate no significant variation in VME performance across patient sex, scanner model, radiation dose, and tube potential. The vessel opacification scores of both VME and SECT demonstrate dependence on patient weight, with VME providing better vessel opacity for both lighter and heavier patients. A measure of 40keV DL-VME derived from SECT effectively enhances both vessel opacification and image quality in CT pulmonary angiography. The image quality advantage of DL-VME over SECT remains robust across variations in data acquisition and patient variables.

In recent decades, there has been marked worldwide growth in diagnostic testing for coronary artery disease (CAD), with several common imaging modalities exposing patients to ionizing radiation. To examine worldwide radiation doses for patients undergoing noninvasive CAD diagnostic testing. This worldwide, cross-sectional study was conducted of radiation dose from noninvasive CAD imaging in 2023, using a consecutive sample of all 19 302 adults undergoing noninvasive CAD diagnostic testing at 742 centers in 101 countries during a single week in October to December 2023. Participants underwent CAD testing with single-photon emission computed tomography (SPECT) or positron emission tomography (PET) nuclear cardiac imaging, cardiac computed tomography for coronary artery calcium scoring (CACS), or coronary computed tomography angiography (CCTA). The primary outcomes were radiation effective dose to patients and the percentage of centers with median effective dose less than or equal to 9 mSv, as recommended in guidelines. Of 19 302 patients, 8515 (44%) were females and the median (IQR) age was 63 (54-71) years. Effective dose varied considerably across diagnostic modalities, with median (IQR) effective dose of 1.2 (0.7-2.2) mSv for CACS, 2.0 (1.6-2.4) mSv for PET, 6.5 (3.9-8.6) mSv for SPECT, and 7.4 (3.5-15.5) mSv for CCTA. Significantly more centers performing nuclear cardiology than CCTA (81% vs 56%; P < .001) and patients undergoing nuclear cardiology studies than CCTA (79% vs 56%; P < .001) achieved median dose of less than or equal to 9 mSv. Doses for the same procedure differed significantly between world regions, being lowest in Western Europe (median [IQR], 4.8 [2.3-7.3] mSv for nuclear cardiology and 4.6 [2.4-9.8] mSv for CCTA) and highest in Latin America for nuclear cardiology (median [IQR], 7.8 [5.3-9.7] mSv) and Africa (median [IQR], 25.2 [14.7-35.3] mSv) for CCTA (P < .001 for all). In regression modeling, there was an inverse relationship between country income level and dose. Patient dose was 20% (95% CI, 3.6%-38.4%) higher in low- and middle-income countries than in high-income countries for nuclear cardiology, and as much as 96% (95% CI, 41.7%-170.8%) higher in low- and lower-middle-income countries than in high-income countries for CCTA (P < .001). Marked variation was observed within income levels and world regions. Given increasing rates of CAD worldwide, these findings of marked variation in radiation dose to patients from diagnostic testing identify a critical need for training, standardized protocols, and updated equipment to reduce radiation worldwide. This especially affects patients in low- and middle-income countries and patients undergoing CCTA. There are therefore important opportunities to improve the quality of CAD diagnosis for patients across the globe.

Abstract Background: Metastatic breast cancer, particularly HER2-positive disease, remains a therapeutic challenge and is often associated with poor prognosis. While anti-HER2 therapies such as trastuzumab have improved outcomes, trastuzumab deruxtecan (T-DXd), an antibody-drug conjugate, has shown promising efficacy even in heavily pretreated patients. Clinical trials, including DESTINY-Breast, have demonstrated significant improvements in progression-free survival (PFS) and overall survival (OS). However, the safety and efficacy of combining T-DXd with radiotherapy (RT) have yet to be fully evaluated. This study aims to assess the outcomes of this combination in patients with HER2-positive and HER2-low metastatic breast cancer. Methods: We conducted a retrospective study including patients treated between November 2020 and January 2024. Patients with HER2-positive and HER2-low metastatic breast cancer who received concurrent trastuzumab der uxtecan and radiotherapy were identified. Data on patient demographics, treatment regimens, radiation doses, toxicity profiles, efficacy and treatment discontinuations were collected. Data on tumor response were collected through imaging examinations, and follow-up was conducted from the last day of radiotherapy until death or the last examination, and toxicities were graded using CTCAE V5.0. Results: The studied population includes 33 patients with HER2-positive and HER2-low metastatic breast cancer who underwent concurrent treatment with trastuzumab deruxtecan and radiotherapy. The median follow-up was 14 months. Treatment details indicated that trastuzumab deruxtecan was administered at the recommended dose across various treatment modalities. Of the patients evaluated, 39.4% achieved partial remis sion, while 9.1% attained complete remission. Additionally, 39.4% experienced stable disease, and 12.1% faced disease progression necessitating a change in therapy. Safety assessment revealed that acute toxicities were mainly associated with systemic treatment. Survival analysis showed 11 deaths (33.3%) during the follow-up period, with a median overall survival of 26 months and median progression-free survival of 12 months. Conclusion: The combination of trastuzumab deruxtecan with radiotherapy in HER2-positive and HER2-low metastatic breast cancer demonstrates promising efficacy with a manageable safety profile. Further studies are warranted to fully elucidate the potential synergistic effects of this treatment regimen and its impact on patient outcomes. Citation Format: J. BOUZIANE, P. Loap, S. Allali, L. Escalup, J. Pierga, Y. Kirova. Concurrent Trastuzumab Deruxtecan and Radiation Therapy in HER2- positive and HER2-low Metastatic Breast Cancer: Assessing the efficacy [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS5-02-15.

X-ray CT has long played a critical role in diagnostic radiology and is also a fundamental component of hybrid imaging in nuclear medicine, providing essential information for anatomic localization of radiopharmaceutical uptake and attenuation correction for PET/CT and SPECT/CT studies. Notably, the radiation dose to the patient from CT can be comparable to or exceed that of the administered radiopharmaceutical, underscoring the need for accurate CT dosimetry to optimize imaging protocols. With the increasing use of CT worldwide in both diagnostic radiology and nuclear medicine, robust tools are needed to assess patient radiation dose and to satisfy regulatory and human-subject research requirements. To address these needs, we developed MIRDct, a software tool integrated within the MIRDsoft.org radiation dosimetry community platform. The code offers organ model-based CT dosimetry and radiation risk metrics tailored for radiology and nuclear medicine applications. MIRDct relies on user-defined inputs for patient characteristics, scanner specifications, and technique parameters to provide rapid and accurate organ-level dose estimates. The software features built-in scan protocols with scan ranges based on predefined anatomic landmarks and supports user-defined custom scan ranges through an intuitive graphic interface. The code leverages a library of 24 state-of-the-art mesh-type phantoms modeling representative adult and pediatric patients of both sexes, configured in either arms-up or arms-down positioning (2 sexes, 6 ages, 2 arm positions). A precomputed Monte Carlo-based dose-coefficient database derived for this library enables instantaneous computation of organ-absorbed doses, effective dose, dose-length product, and size-specific dose estimates. MIRDct also provides risk-related metrics, including detriment-weighted dose, lifetime attributable risk, and risk index, and incorporates optional uncertainty quantification and error propagation to provide a quantitative indicator of estimate reliability. Dose estimates from MIRDct were benchmarked and compared across 4 scan protocols with other available codes (the National Cancer Institute dosimetry system for computed tomography and VirtualDose), demonstrating reasonable agreement (4%-30% differences for effective dose). Version 1.1, available at MIRDsoft.org, presents all underlying calculations through a transparent spreadsheet-based implementation and offers advanced features to support CT protocol optimization, deepen dosimetry insight for patient-care-related evaluations, and aid in quality assurance.

BackgroundThe recommendation level for left atrial appendage occlusion (LAAO) via device implantation has increased in the most recent American College of Cardiology (ACC) guidelines, resulting in an increase in implantation rates. Our center had the unique experience of originally implanting Watchman deviceTM (Boston Scientific, Marlborough, MA, US) devices from 2017 to 2021 and abruptly switching to implanting Amplatzer AmuletTM (Abbott Cardiovascular, Plymouth, MN, USA) devices from 2021 to the current day. This sudden switch between devices created a unique opportunity for direct comparisons of the two LAAO devices. Our study aimed to compare the differences between these two devices regarding procedural time, radiation dose, and contrast use.MethodsSeveral patients (n=1262) underwent LAAO implantations from 2017-2024 at our center. We performed simple random sampling to select 200 patients that received the Watchman devices and 200 patients that received the Amulet devices. Demographic information, procedural time, radiation dose, and contrast doses were collected for all of them. Student’s t-tests were performed on continuous variables for statistical analyses. ResultsThe average procedure time overall was 56.71 minutes. The average radiation dose of patients undergoing the Watchman device implantation was 167.5 mGy (95% CI: 140.9-194.1) and 247.0 mGy (95% CI: 201.4-286.7) for the Amulet device (p=0.001). The average procedure time did not differ as it was 52.4 minutes (95% CI: 48.7-56.1) for the Watchman device implantation versus 56.1 minutes for the Amulet implants (95% CI: 52.1-60.1; p=0.183). The average contrast dose also did not differ, as patients undergoing the Watchman device implantation used 31.3 cc (95% CI: 27.8-34.8), whereas it was 34.5 cc (95% CI: 31.4-37.7; p=0.176) with the Amulet device. ConclusionThere was a significantly higher radiation dose associated with the implantation of the Amulet versus the Watchman devices. There were no significant differences between procedural time or contrast use between the two devices.

Evidence on the influence of eloquent brain areas on the effectiveness and side effects of radio-therapy (RT) remains limited. This study evaluated the relationship between eloquent brain regions, radiation dose, and tumor recurrence patterns in glioma patients. Preoperative navigated transcranial magnetic stimulation (nTMS) mapping of language and motor function, complemented by nTMS-based tractography, was performed. Magnetic resonance imaging of tumor recurrence was co-registered with RT treatment plans and functional nTMS data. Tumor growth direction, radiation dose to eloquent structures, and clinical outcomes were analyzed. Seventy-two patients with glioblastoma, aged 57.7 ± 14.8 years, were included. Tumor recurrence toward eloquent brain areas, assessed either by volumetric or linear measurements, indicated growth affecting motor function in 68.1% and language function in 79.3% of patients. Following RT, new motor deficits occurred in 3/48 patients (6.3%) and language deterioration in 3/20 (15.0%). The mean dose to the corticospinal tract was 10.1 Gy in patients with motor decline versus 3.7 Gy in those without (P = .137). For language fiber tracts, corresponding doses were 34.1 Gy and 15.1 Gy (P = .073). Tumor recurrence toward eloquent brain areas was observed, with high radiation doses to eloquent brain areas being associated with higher rates of neurological deterioration. These findings create an ambiguous situation regarding the application of high radiation doses to the resection cavity facing eloquent brain areas while simultaneously ensuring optimal dose gradients to spare those.

To investigate if there has been an elimination of gonadal and fetal shielding during routine abdominal and pelvic imaging compared with other radiologic examination types such as torso or extremity examinations. This original, mixed-methods, pilot research study used an anonymous 22-question survey to collect data. Respondents drawn from social media groups, cold calls, and current colleagues of the author were asked to complete the survey during a 31-day period. Questions were focused on the responding technologists' demographics and when they shield patients based on examination type, age, and sex. Of the 38 survey respondents, 36 stated they would not shield during pelvis imaging; 15 stated they would not shield during torso imaging; 31 stated they would not shield during lumbar imaging; and 10 stated they would not shield during extremity imaging. The survey results also showed that patients' age, sex, and risk of covering anatomy have a vital role in current shielding practices. However, 25 respondents stated that their employer does not have a different shielding protocol for male and female patients. Of the respondents, 89% reported having a rolling lap shield available for use during upright imaging studies. Findings showed that many technologists do not shield during various examinations. This study provides a starting point for future research and acknowledges a shift in shielding practices. The findings of this study can be used by administrators and other professionals when examining their current shielding protocols. The results from this pilot survey show that, in addition to patient radiation dose, other important factors, such as examination type and patient age, influence a technologist's decision to shield.

Effect of iodinated contrast media enhancement on size-specific dose estimates in emergency thoracic CT.

BackgroundStandardized care pathway (SCP) for macrohematuria (patients aged ≥50 years) in Sweden includes four-phase computed tomography urography (CTU) before cystoscopy, but targeted SCP lead time for CTU (6 days)/treatment is fulfilled in <25% of patients.PurposeTo retrospectively analyze the incidence of CTU-diagnosed upper urinary tract (UUT), kidney and bladder tumors, calculi, radiation dose, and its implications for SCP.Material and MethodsA total of 4491 consecutive CTU reports on macrohematuria indication were reviewed, mainly during 2022 (86.6%) from nine radiology units: four regions, three university hospitals, and two private units. Tumor findings were verified via biopsy/cytology reports, CTU characteristics, and follow-up. Effective patient radiation doses were calculated.ResultsIn patients aged ≥50 years (n = 3915) the incidence of UUT/kidney/bladder tumors was 0.9%/1.0%/6.9%, respectively, and of calyceal, pelvic, ureteral, and bladder calculi was 13%, 2.0%, 2.7%, and 2.2%, respectively. Median effective dose was 12.9 mSv (range=10-22 mSv) in the six radiology units using four-phase CTU in 87%-100% of the examinations and 9-12 mSv in the three units using four-phase in 3%-53%.ConclusionThe limited incidence of UUT and kidney tumors diagnosed at CTU for macrohematuria necessitates a multidisciplinary discussion on how to improve SCP lead times for the vast majority with urothelial tumors, i.e. bladder tumors. Alternative diagnostic pathways such as cystoscopy and clinical risk evaluation before CTU should be contemplated. Additionally, there is a need to optimize radiation dose by reducing the number of CTU phases on one hand and without losing significant diagnostic accuracy on the other hand.

BackgroundTo validate the clinical safety and efficacy of a domestically produced robotic-assisted system (YDHB-NS01) for cerebral angiography and to review the current status, advantages, and challenges of robot-assisted technology in cerebrovascular interventions.MethodsFrom May to October 2025, 25 consecutive patients who underwent robotic-assisted cerebral angiography and 25 consecutive patients who underwent manual cerebral angiography at our center were prospectively enrolled. The primary endpoints were technical success rate and clinical success rate. Secondary endpoints included procedure time, fluoroscopy time, radiation dose, contrast volume, total angiography room time, device performance evaluation, and complication rate. Additionally, a literature review was conducted to summarize the applications and developments of various robotic systems in neurointervention.ResultsAll 50 (25 in the robotic-assisted group and 25 in the manual group) procedures were successfully completed with a 100% technical success rate. There were no differences between the two groups in patients’ demographic data, fluoroscopy time, patient radiation dose, contrast agent dose, or total angiography room time (all p > 0.05). The robotic-assisted group had a shorter procedure time than the manual group (27 [15, 143] vs. 38 [21, 105], p = 0.005). A learning curve for the robotic-assisted system was observed. The robotic-assisted system operated stably without malfunctions. No procedure-related or device-related complications occurred.ConclusionThe preliminary clinical application demonstrates that the YDHB-NS01 robot-assisted system is feasible for diagnostic cerebral angiography and shows early indications of safety and comparable procedural performance to those of conventional manual methods. Given the small, single-center cohort and the exploratory nature of this study, larger multicenter controlled trials are required to confirm these findings.Supplementary InformationThe online version contains supplementary material available at 10.1186/s41016-026-00426-w.

Digital radiography of the sacrum requires precise adjustments of exposure parameters (kV, mA, time) to produce high-quality images while minimizing radiation exposure. This study aims to investigate how these exposure factors affect the quality of sacral images and to recommend optimal settings that align with radiation safety principles such as ALARA. By reviewing the existing literature, it was found that the modification of exposure parameters (kV, mA, time) in digital radiography is essential for achieving optimal image quality while minimizing radiation exposure. The exposure index (EI) serves as an indirect measure of the dose absorbed by the detector, thereby facilitating the implementation of the ALARA principles. Properly orienting the AEC chamber can reduce radiation dose by up to 44% without compromising image quality. Tube voltage and current adjustment enhances image contrast and sharpness. Nonetheless, inconsistent exposure methods and dependence on presets can still lead to dose creep. It is essential to train radiographers, adjust equipment settings, and set Diagnostic Reference Levels (DRLs) to enhance imaging quality and ensure patient safety. In digital radiography, factors such as tube voltage (kV), tube current (mA), and exposure time (s/mAs) significantly affect image quality and patient radiation dose. Adjusting exposure settings according to patient characteristics and exam objectives enhances image quality and reduces radiation exposure, particularly in sensitive areas like the sacrum. Technologies such as Exposure Index (EI), Automatic Exposure Control (AEC), and image analysis software facilitate an objective method that follows the ALARA principle, ensuring patient safety while optimizing diagnostic outcomes.

A treatment planning system (TPS) is responsible for calculating the radiation dose for patients undergoing brachytherapy. However, to verify TPS dose accuracy of intracavitary brachytherapy, which feature particularly steep and complex dose gradients, 3D-printed phantoms made of polylactic acid (PLA) can be used. A study was designed to create an in-house phantom for verification of gynecological brachytherapy measurement using a radiophotoluminescent glass dosimeters (RPLGDs) and to evaluate the dosimetric differences between measurement and calculation by the treatment planning system under clinical conditions.An in-house phantom holder was designed to move the axis of the holder to the rectum point that differs according to the patient's anatomy. The holder of the applicator was designed for various types of applicators in intracavitary brachytherapy. This clinical study was used to quantify variations between the calculated and measured dose for 6 plans at various points in the phantom, which included point A, point B, the bladder point, and the rectum points.The RPLGDs demonstrated a linear dose response up to 10 Gy, excellent angular dependence, and an associated uncertainty of 3.3% (k = 1). In the clinical case, the dose differences between the measured and calculated values at Point A, Point B, bladder, and rectum were +1.99 ± 1.11%, 1.01 ± 0.02 Gy, and 0.10 Gy, +4.42±2.56%. and + 3.53 ±1.44%, respectively.Dosimetry with RPLGDs using the 3D printed in-house phantom can accurately verify delivered dose in intracavitary brachytherapy for quality assurance purposes.

Objective: The number of operators performing mechanical thrombectomy (MT) may influence procedural outcomes; however, evidence remains limited and conflicting. This study aimed to comprehensively evaluate the impact of single versus dual operators on procedure time, radiation dose, and angiographic success in patients undergoing MT for acute ischemic stroke. Methods: In this single-center, retrospective cohort study, 285 consecutive patients who underwent MT for large-vessel occlusion between January 2020 and December 2024 were included. Patients were grouped according to institutional workflow: single-operator procedures (n = 157) and dual-operator procedures (n = 128). The primary endpoints were procedure time and radiation dose parameters, including total Kerma-Area Product (PKA). Secondary endpoints included successful reperfusion (TICI ≥ 2b), complete reperfusion (TICI 3), and first-pass success (FPS, defined as TICI 2c/3 with a single pass). Results: Baseline characteristics were comparable between groups. The dual-operator group had significantly shorter median procedure times (52.5 vs. 85.0 min, p < 0.001) and lower total PKA (p < 0.001). Reperfusion rates were significantly higher in the dual-operator group, both for successful reperfusion (TICI ≥ 2b: 80.5% vs. 64.3%, p = 0.004) and complete reperfusion (TICI 3: 76.6% vs. 58.5%, p = 0.002). First-pass success was also more frequent (60.0% vs. 44.5%, p = 0.0146), and the mean number of passes was lower (1.66 vs. 2.00, p = 0.0057). Conclusions: Mechanical thrombectomy performed with two experienced operators was associated with greater procedural efficiency, reduced patient radiation exposure, and higher angiographic success compared with single-operator procedures. These findings support considering the dual-operator model as an approach that may inform workforce planning and workflow decisions in stroke centers.