Objective:To study the effects of different doses of X-ray irradiation on the immune microenvironment and cGAS-STING signaling pathway of hepatocellular carcinoma cells.Methods:C57BL/C mice were subcutaneously injected with Hepa 1-6 hepatocellular carcinoma cells in the right axilla to establish a subcutaneous tumor-forming hepatocellular carcinoma model. The mice were randomly divided into 0, 4, 8, 12 Gy irradiation groups, with 10 mice in each group. The body weights and tumor volumes were monitored. Specimens were collected 28 d after irradiation. The ELLSA and Flow Cytometry method was used to compare the macrophage-associated cytokines tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-6 (IL-6), chemokine ligand 5 (CCL5), IL-10, IL-13, transforming growth factor-β (TGF-β), IL-4 and macrophage M1, M2 phenotype ratio (M1/M2). Real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) and immunoblotting assay were used to detect the expression of genes and proteins related to the cGAS-STING signaling pathway in hepatoma cells.Results:With the increase of irradiation dose, the tumor volume was significantly reduced ( F=8.42, P<0.05), the proportion of cell necrosis increased ( F=3.89, P<0.05), the content of macrophage-associated cytokines other than IL-4 increased ( F=6.32-15.50, P<0.05), and the proportion of M1 and M2 types of macrophage in the immune microenvironment of hepatocellular carcinoma tumors was elevated ( F= 5.46, 5.14, P < 0.05).The gene expression and protein expression levels of cGAS-STING signaling pathway were elevated in hepatocellular carcinoma cells (mRNA expression of cGAS and STING: F=6.35, 16.10, P<0.05; protein expression of cGAS and STING: F=71.31, 37.15, P<0.05). Conclusions:X-ray irradiation activates the cGAS-STING signaling pathway in hepatocellular carcinoma cells and contributes to the remodeling of the tumor immune microenvironment.

Objective:To identify micronuclei through the cytochalasin B blocking micronucleus method-based assay using scanning microscope, combined with the slide scanning software Metafer 4 and, accordingly, to establish a dose-response relationship between the dose of 60Co γ-rays and the frequency of micronuclei in human peripheral blood lymphocytes using artificial intelligence-based color recognition. Methods:Blood samples were collected from four healthy individuals (two men and two women) and were then exposed to varying doses of 60Co γ-ray radiation (0, 0.25, 0.5, 1, 2, 3, 4, 5 Gy) at a dosage rate of 0.74 Gy/min. Micronucleus slides were prepared as per the GBZ 128-2023 standard. The numbers of binuclear cells and micronuclei were recorded using an artificial intelligence-based color recognition analysis system. The dose-response curve was determined through fitting using the CABAS software. Then, the doses to both independent samples were estimated based on the curve. Results:Within a dose range of 0 to 5 Gy, the fitted micronucleus dose-response curve aligned with a quadratic polynomial model, with a regression equation of y = 0.032 1 D2+ 0.023 7 D+ 0.012 7 ( D denoting the dose, correlation coefficient R2=0.998). The dose estimations from the validation samples closely corresponded to the actual irradiation doses. Conclusions:Establishing the micronucleus dose-response curve provides a feasible method and basis for the rapid and accurate estimation of radiation biological doses in laboratory automation.

Objective:To investigate the incidence of radiation pneumonitis (RP) induced by 125I seed implantation for the treatment of malignant lung tumors and analyze related dosimetric parameters. Methods:A retrospective analysis was conducted on 31 cases of malignant lung tumors treated with 125I seed implantation from January 2017 to December 2022 at Hebei Provincial Tumor Radioactive Seeds Implantation Diagnosis and Treatment Center. These cases consisted of eight patients with squamous cell carcinoma, 10 patients with adenocarcinoma, and 13 patients with metastatic cancer in other sites. At 1-6 months after treatment, these patients received postoperative chest CT scans, with the efficacy evaluated based on the Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1), including the objective response rate (ORR) and the disease control rate (DCR). The efficacy of RP was evaluated using the Radiation Therapy Oncology Group (RTOG) criteria. Postoperative dosimetric parameters, including D90 (minimum peripheral dose received by 90% of the target volume), V8 (percentage of lung volume receiving 8 Gy), V32 (percentage of lung volume receiving 32 Gy), and Dmean (mean radiation dose) of the affected lung, were statistically analyzed. The relationships of the RP occurrence with postoperative D90, V8, V32, and Dmean were analyzed by comparison with relevant external radiotherapy data, to identify the parameters that are correlated closely with RP occurrence. Results:All the patients underwent successful surgeries. The postoperative efficacy evaluation after six months showed complete response (CR) in 11 cases, partial response (PR) in 11 cases, stable disease (SD) in eight cases, and progressive disease (PD) in one case, with an overall response rate (ORR) of 71.0%, and a disease control rate (DCR) of 96.8%. Three patients suffered RP, with an incidence rate of 9.7%. Postoperative V8, V32, and Dmean could not serve as predictive indicators for RP. Follow-up observation revealed that three RP cases (3/5) exhibited postoperative D90 exceeding 170 Gy and no RP cases (0/26) showed postoperative D90 below 170 Gy. Conclusions:In the treatment of malignant lung tumors with 125I seed implantation, there is a certain correlation between RP and postoperative D90, while there is no correlation between it and V8, V32, and Dmean.

Objective:To investigate the correlations of urinary adverse reactions with dose to the bladder and urethra during external pelvic irradiation for locally advanced cervical cancer.Methods:This study retrospectively collected relevant dosimetric parameters and urinary symptoms, such as frequent, urgent, and painful urination, from locally advanced cervical cancer patients treated with external pelvic irradiation in the Department of Oncology, Affiliated Hospital of Guizhou Medical University. The dosimetric parameters examined in this study included the maximum, minimum, and mean doses to bladder and urethra (i.e., Dmax, Dmin and Dmean), mean doses received in an area of 0.1, 1, and 2 cm 3 around the planning target volume, D0.1 cm 3, D1 cm 3, D2 cm 3, and percentages of irradiated volumes in the whole organ volume under doses of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 Gy, V5 Gy, V10 Gy, V15 Gy, V20 Gy, V25 Gy, V30 Gy, V35 Gy, V40 Gy, V45 Gy, V50 Gy. Then the correlations between urinary symptoms and these dosimetric parameters were analyzed using the independent-sample t-test and the Logistic regression model. Results:The median volumes of bladder and urethra were 294.8 and 4.71 cm 3, respectively. Patients were divided into two groups based on the median division. The univariate analysis showed that urethral Dmax, Dmin, Dmean, V5 Gy, V10 Gy, V15Gy, V20 Gy, V25 Gy, V30 Gy, V35 Gy, V40 Gy, V45 Gy and V50 Gy correlated with urinary complications ( t = 14.30, 21.65, 32.19, 33.36, 16.62, 17.91, 21.52, 20.11, 12.27, 37.25, 30.18, 36.24 and 21.98, P<0.05). The multivariate analysis further indicates that urethral D2 cm 3, V20 Gy, V40 Gy and Bladder V40 Gy, D1 cm 3, D2 cm 3 were independent predictors of grade 2 urinary adverse reactions ( P<0.05). Conclusions:This study reported the correlations of relevant dosimetric parameters of urethra with urinary toxicity during external pelvic irradiation. It holds that urethral D2 cm 3, V20 Gy and V40 Gy should be restricted to minimize the risks of grade 2 urinary complications.

Objective:To evaluate the clinical application value of the adaptive aperture by comparing intensity-modulated proton radiotherapy(IMPT) plans using and not using the aperture for brain tumors.Methods:A total of twenty patients treated with postoperative radiotherapy for brain tumors were enrolled in this study. IMPT plans were developed for each patient using and not using the adaptive aperture under the same optimization conditions. The target conformal index (CI) value, target homogeneity index (HI) value, and the dose to normal tissues of the two sets of plans were compared.Results:The IMPT plans designed using the adaptive aperture significantly increased the mean CI value from 0.58 to 0.66, while decreasing the mean 50% prescription dose volume from 797.70 cm 3 to 638.15 cm 3. These plans also reduced the irradiation doses to the cochlea, brainstem, optic chiasm, optic nerve, and lens ( t = 2.06, 3.02, 2.11, 2.58, 2.67, P < 0.05). Additionally, there was no significant difference in the HI value of the target volumes and the machine jumps (MU) between the two sets of plans ( P > 0.05). Conclusions:The adaptive aperture can significantly reduce the irradiation dose to normal tissues outside the target volumes, positively impacting the protection of organs at risk (OARs) around the target values. This demonstrates its great potential for clinical application.

Objective:To investigate the trend of radiological diagnostic examination frequency and the related influencing factors in a general hospital in recent four years.Methods:The hospital information system and the radiology information system were used to collect the information on the numbers of the outpatients, the emergency patients, and the inpatients and the radiology examination information from 2019 to 2022. The examination frequency and proportion of various imaging equipment were counted by using the perspective table of data, and the examination items and the proportion of the radiological diagnostic examinations were calculated. The positive rates of the radiological examinations were measured from 2019 to 2022. The gender and age distribution of the patients were analyzed. Spearman correlation analysis was used to analyze the relationships between the numbers of the patients undergoing radiological examinations and the numbers of the outpatients, emergency patients and the inpatients.Results:The annual frequency of radiological diagnostic examinations from 2019 to 2022 were 307 306, 245 418, 317 250 and 325 625, respectively, with a total of 1 195 599. Among them, the proportions of CT, X-rays, bedside X-rays, bone density, gastrointestinal imaging and mammography were 59.74%, 38.04%, 1.39%, 0.42%, 0.21% and 0.19%, respectively. In each year, the proportion of CT in all radiological diagnostic examinations was 49.58%, 63.40%, 60.40% and 65.20%, respectively. The frequency of emergency CT and emergency chest CT was correlated with the number of emergency patients( r =0.63, 0.61, P<0.05), and the frequency of non-emergency CT was correlated with the number of outpatients and inpatients ( r =0.61, 0.66, P<0.05). The positive rates of the CT examinations were higher than 80% except the lowest of 79.95% in 2021. Conclusions:Radiological examinations especially CT examinations have increased significantly, and played an important role in the diagnosis of diseases. However, attention should be paid to the Justification of the CT examinations. Timely statistical analysis of radiological examination information can provide data supports and references for scientific management of radiological examinations.

Objective:To explore the radiological protection measures for yttrium-90 ( 90Y)-loaded resin microsphere therapy in clinical application. Methods:The surgical operation process for 90Y-loaded resin microsphere therapy was simulated, involving measurement of ambient dose equivalent rates at various stages: preoperative preparation (dominated by drug package), drug transfer, intraoperative procedures (drug operation and injection), and postoperative care and observation within the hospital. Based on the simulation, the protection measures in clinical application were analyzed. Results:The dose equivalent rate ranged from 0.12 to 0.42 μSv/h around the active chamber and from 1.04 to 3.32 μSv/h in the fume hood. Around the digital subtraction angiography (DSA) room, the maximum dose equivalent rate was 0.78 μSv/h when 90Y and DSA were applied simultaneously and 0.36 μSv/h when 99Tc m and DSA were applied. For the first operating position in the fluoroscopy protection area, the maximum dose equivalent rate was 13.19 μSv/h at 155 cm height when only 90Y was applied, and 315.01 μSv/h at 80 cm height when 90Y and DSA were applied. For the second operating position, the maximum dose equivalent rate was 6.28 μSv/h at 155 cm height when only 90Y was applied and 291.03 μSv/h at the same height when 90Y and DSA were applied. The dose-equivalent rates ranged from 0.11 to 0.58 μSv/h around the dedicated ward for postoperative patients. Conclusions:The existing shielding measures, such as those in the nuclear medicine department and interventional room, meet the radiation protection requirements for 90Y-loaded resin microsphere therapy. However, it is still necessary to conduct a scientific assessment based on the actual situation. Additionally, radiation protection measures and surface contamination treatment should be enhanced during drug operation.

Objective:To evaluate the feasibility of low radiation dose and low contrast dosage in coronary CT angiography (CCTA) of class I obese patients.Methods:This prospective study enrolled 57 patients (male/female, 50/7, age, 25-77 years) with body mass index (BMI) of 30-38 kg/m 2 and body weight of 85-119 kg scheduled for CCTA from August 2022 to March 2023 in our hospital. The patients were divided into two groups: control group (group A, n = 20) and low-dose group (group B, n = 37). Group A employed a standard-dose protocol: tube voltage 120 kVp and IDR 2.2 g I/s, while group B were scanned using the low-dose protocol: tube voltage 100 kVp and IDR 1.5 g I/s. Images in Group A and Group B were reconstructed with hybrid iterative reconstruction (HIR) at strength 4 and 8, respectively. Other scanning and reconstruction parameters were the same in two groups. Methods:The image quality was assessed by measuring the CT values and noise in the aortic root, left anterior descending artery and right coronary artery, and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective image quality was evaluated for vessels according to the 18-segment classification system using a 4-point scale (1. poor, 4. excellent). The effective dose E and contrast dosage were compared. Statistical analysis was performed using independent samples t-test, Mann-Whitney U test or χ 2 test. Results:The BMI of groups A and B were 31.89 (30.77, 33.81) and 31.22 (30.46, 32.83) kg/m 2, respectively ( P>0.05). No statistically significant differences in CT values, noise, SNR, CNR were noticed between the two groups (all P>0.05). The mean subjective score of all coronary artery segments in the two groups were not less than 3, meeting the requirement of clinical diagnosis. There was no statistically significant difference in the overall subjective image quality between the two groups ( P>0.05). The radiation dose E in groups A and B were 7.58 and 4.49 mSv, respectively ( Z=-5.46, P<0.05). The contrast dosage in groups A and B were 66 and 45 ml, respectively. The radiation dose E and contrast dosage in group B were 41% and 32% lower than that in group A, respectively. Conclusions:For class I obese patients, it was feasible to use a low tube voltage (100 kVp) and low IDR (1.5 gI/s) protocol in CCTA. Radiation dose and contrast dosage can be reduced reasonably without compromising the CCTA image quality.

Objective:To assess the radiation dose and clinical value of "one-stop" whole-brain CT perfusion (CTP) imaging in the evaluation of collateral circulation for patients with acute ischemic stroke (AIS), regarding the digital subtraction angiography (DSA) as the reference.Methods:This retrospective study included 32 AIS patients, for whom both CTP and DSA were obtained <24 h since onset. All CTP scans were acquired in whole-brain volume perfusion mode using a 320-row CT with the phase-specific settings of tube currents to optimize the image quality of CTA images, where multiple-phase (mp) CTA images were extracted from the CTP data in post-processing. The volume CT dose index (CTDI vol), dose length product (DLP), and effective dose were compared to those reported in previous studies. The perfusion parameters of the infarct lesions and their contralateral regions were compared using the paired t-tests. One radiologist scored the collateral circulation with only the CTP and with the CTP plus mp-CTA using a 5-point scale. Another radiologist performed the same evaluation on the DSA. The diagnostic accuracy was calculated referring to the result based on DSA. The scores were analyzed using the Pearson correlation coefficient. The agreement of scores was quantified with the Kappa test. Results:The mean CTDI vol was 184.18 mGy, which was comparable to the result of a previous study (184.19 mGy), and the mean effective dose was reduced 39% compared to that reported in the literature for combined CTP and CTA scanning (6.1 vs 10 mSv). There were statistically significant differences in cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), transit time to peak (TTP), and time-to-maximum (Tmax) between the infarct lesions and their contralateral regions ( P<0.01). The scores between CTP and DSA were significantly correlated ( r=0.95, P<0.01), as well as the scores between CTP plus mp-CTA and DSA ( r=0.98, P<0.01). The Kappa value was 0.64 ( t=7.53, P<0.01) between CTP and DSA, while it increased to 0.88 ( t=9.99, P<0.01) for CTP plus mp-CTA. With the result of DSA as a reference, the diagnostic accuracy was 71.9% and 90.6% for CTP and CTP plus mp-CTA, respectively. Conclusions:The "one-stop" whole-brain CTP imaging with phase-specific settings of tube currents can provide reliable CTP and multiple-phase CTA images simultaneously, which could reasonably reduce the radiation dose. Combined use of multi-phase CTA and CT perfusion improves the diagnostic accuracy of collateral circulation in AIS patients.

Objective:To explore the differences between the deep learning-based image reconstruction (DLIR) and the adaptive statistical iterative reconstruction V (ASiR-V) algorithms in the radiation dose and image quality of head and neck CT angiography (CTA).Methods:The data of 80 patients undergoing head and neck CTA due to vascular diseases in the head and neck were prospectively collected. These patients were randomly divided into groups A and B based on their examination sequence. The CTA images of group A were reconstructed based on ASiR-V 50%, with a tube voltage of 120 kV and a noise index of 11.0. In contrast, those of group B were reconstructed based on ASiR-V 50% (for group B1) and DLIR-H (for group B2), with a tube voltage of 80 kV and a noise index of 9.0. Then, the radiation doses and image quality of both groups were compared using the independent-sample t-test. The radiation doses, and both subjective and objective image quality of the two imaging method were compared through the Kruskal-Wallis test and the Wilcoxon rank-sum test. The independent- or paired-sample t-test was employed to measure inter-group vascular enhanced CT values, as well as signals and noise from regions of interest (ROIs), with signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) calculated. Results:The effective doses of groups A and B were (0.77±0.08) and (0.45±0.05) mSv, respectively, with a statistically significant difference ( t = 21.96, P < 0.001). The vascular enhanced CT values, SDs, SNRs, and CNRs in the arch of the aorta, the initial and bifurcation parts of the common carotid artery, and the M1 segment of the middle cerebral artery showed statistically significant differences among groups A, B1, and B2 ( F = 67.69, 68.50, 50.52, 74.10, 63.10, 91.22, 69.16, P < 0.001). Additionally, statistically significant differences were observed in the subjective scores of image quality among groups A, B1, and B2 ( Z = 71.06, P < 0.05). Conclusions:The DLIR algorithm can further reduce the radiation dose in head and neck CTA examination while significantly reducing image noise and ensuring image quality, thus demonstrating high clinical application value.