Current IssueArchive
2024 Volume 33 Issue 4
Published: 28 August 2024
  
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  • Original Articles
    CUI Limeng, FENG Zechen, JIN Guoliang, MA Yongzhong, MA Xiaolong, MA Xiaohai
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    Objective To compare the response capability of active personal dosimeters (APDs) in the pulse radiation field of interventional radiology, and to find APDs that can be used for dose optimization monitoring for interventional radiology staff. Methods Seven models of APDs and dose monitoring systems were tested in the following four types of radiation fields: continuous radiation field (Cs-137), single-pulse radiation field (80 kV, 10 mA, 10~1000 ms), multi-pulse standard radiation field (70 kV, 20~500 mA, 1~20 ms/pulse, frames per second 1~20), and multi-pulse scattering field (angiography machine, irradiation field: 15 cm × 15 cm, 22 cm × 22 cm, 27 cm × 27 cm, angiography: 65~74 kV, 6.2~8.2 mA; photography: 65 kV, 343~479 mA). Results All APDs showed good dose responses in the continuous radiation field. The ratio of the results obtained with and without phantom was 1~1.1. In the single-pulse radiation field, DMC3000 and TruDose showed good dose response, linearity, and repeatability. Under the main ray of the multi-pulse radiation field, DMC3000 and TruDose showed good dose response, linearity, and repeatability as the dose rate increased, and there were 5%~13% differences in the response ability between the two models. In angiography machine scattering field, the ratios of the results obtained from DMC3000, TruDose, and RaySafei3 to those from thermoluminescence dosimeter were 1.08 ± 0.09, 0.95 ± 0.11, and 1.13 ± 0.11, respectively. Conclusion DMC3000, TruDose, and RaySafei3 can be used in clinics as auxiliary dosimeters to optimize radiation dose monitoring and radiation protection measures for people at high risk of occupational diseases. Interventional radiology workers can implement actions to reduce the cumulative dose based on real-time dose information, thereby reducing the radiation dose.
  • Original Articles
    KONG Lingnan, YANG Baolu, ZHANG Jing, ZHOU Qiang
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    Objective To develop a large-volume sample cassette in the shape of a formalin cup suitable for portable HPGe γ spectrometer, to determine the detection limits of the cassette at different detection times through fresh sample measurements, and to provide a reference for responding to and monitoring of nuclear and radiation emergencies. Methods According to the formula for calculation of detection limit described in the GB/T 16145—2022, 131I and 137Cs were measured using the sourceless efficiency calibration software Angle and the portable HPGe γ spectrometer for the optimization of the large-volume sample cassette. Fresh salmon samples were measured using a formalin cup-shaped large-volume sample cassette. The detection times were 2, 4, 6, 8, 10, 19, 19, 22, and 24 hours. The relationship between detection time and detection limit was assessed. Results Using sample cassettes with 15 cm radius and 10 L volume, the simulated detection efficiency of the formalin cup-shaped large-volume sample cassette was 30%-46% higher and the detection limit was lower as compared with the cake-shaped large-volume sample cassette. The detection limit obtained by measuring fresh salmon samples decreased with the extension of the detection time. These results provided a reference for the detection limits of measuring fresh samples for nuclides of concern in nuclear contaminated water with different detection times. Conclusion The formalin cup-shaped large-volume sample cassette developed by combining the optimization of detection limit provides a geometry for quantitative analysis in on-site monitoring of γ nuclides in the case of emergencies. Measurement of fresh samples using the cassette with different detection times showed that 8-10 hours of detection was optimal in balancing the detection limit and the detection time.
  • Original Articles
    ZHANG Yanbiao, WANG Chuangao, GUO Luzhen, WU Mengmeng, PANG Hongchao, LUO Zhiping, CHEN Ling
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    Objective To investigate the separation efficiency of three physical separation methods for gaseous 14C, namely membrane separation, adsorption separation, and low-temperature separation, to screen for the optimal separation method, and to provide a reference for the separation and enrichment of 14CO2 in online monitoring of 14C. Methods The experimental plan was designed, and three devices were constructed for separation and purification experiments. The purity, recovery rate, and separation time of CO2 separated by the three methods were analyzed. Results All the three methods achieved the separation of CO2. Under certain conditions, 20 mL of sample gas was obtained. The separation time of membrane separation method was 0.5 hour, CO2 gas with a sample purity of 0.0486%-0.0488%VOL was obtained, and the recovery rate was only 2.5%?12.7%. The separation time of MOF material adsorption separation method was 24?30 hours, CO2 gas with a sample purity of 20.2%?47.5%VOL was obtained, and the recovery rate was 57.3%?63.2%. The separation time of low-temperature separation method was 3 hours, CO2 gas with a sample purity of 96.0%?99.8%VOL was obtained, and the recovery rate was 81.5%?92.5%. Conclusion The purity and recovery rate of CO2 with low-temperature separation method were higher compared to membrane separation method and MOF material adsorption separation method. The separation time of low-temperature separation method was moderate. The low-temperature separation method can provide a reference for the enrichment technology of 14C in the rapid measurement of gaseous 14C effluent.
  • Original Articles
    SUN Yaru, WANG Huan, YAO Meinan, MA Yongzhong, BAI Bin
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    Objective To investigate the method of tube furnace oxidation combustion and liquid scintillation counting for the determination of carbon-14 in seafood, and to provide technical support for the monitoring of carbon-14 in seafood. Methods By studying the pyrolysis characteristics of five types of dried seafood samples, including yellow croaker, white shrimp, swimming crab, clam, and seaweed, a temperature control program suitable for the oxidation combustion of seafood was established. The combustion efficiency, carbon element recovery rate, and the accuracy and precision of the method were determined. Results The combustion efficiency was more than 98% for most seafood using the recommended combustion program. The recovery rate of carbon was similar to that calculated by glucose combustion; both were more than 95%. Four laboratories validated the accuracy of the method by measuring the carbon-14 activity concentration in the Chinese sugar carbon standard material. The relative errors ranged from 1.03% to 3.41% and the average relative error was 2.36%. The precision of this method was verified by measuring the carbon-14 activity concentration in yellow croaker samples. The within-laboratory relative standard deviation ranged from 5.11% to 9.35% and the between-laboratories relative standard deviation was 4.04%. Conclusion The tube furnace oxidation combustion and liquid scintillation counting method was used to determine the activity concentration of carbon-14 in seafood. The recommended oxidation combustion program is more targeted and less time-consuming. The accuracy and precision of this method meet the requirements. This method is suitable for the determination of carbon-14 in seafood.
  • Original Articles
    XUE Xian, WANG Kaiyue, LIANG Dazhu, DING Jingjing, JIANG Ping, SUN Quanfu, CHENG Jinsheng, DAI Xiangkun, FU Xiaosha, ZHU Jingyang, ZHOU Fugen
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    Objective To evaluate the application of three deep learning algorithms in automatic segmentation of clinical target volumes (CTVs) in high-dose-rate brachytherapy after surgery for endometrial carcinoma. Methods A dataset comprising computed tomography scans from 306 post-surgery patients with endometrial carcinoma was divided into three subsets: 246 cases for training, 30 cases for validation, and 30 cases for testing. Three deep convolutional neural network models, 3D U-Net, 3D Res U-Net, and V-Net, were compared for CTV segmentation. Several commonly used quantitative metrics were employed, i.e., Dice similarity coefficient, Hausdorff distance, 95th percentile of Hausdorff distance, and Intersection over Union. Results During the testing phase, CTV segmentation with 3D U-Net, 3D Res U-Net, and V-Net showed a mean Dice similarity coefficient of 0.90 ± 0.07, 0.95 ± 0.06, and 0.95 ± 0.06, a mean Hausdorff distance of 2.51 ± 1.70, 0.96 ± 1.01, and 0.98 ± 0.95 mm, a mean 95th percentile of Hausdorff distance of 1.33 ± 1.02, 0.65 ± 0.91, and 0.40 ± 0.72 mm, and a mean Intersection over Union of 0.85 ± 0.11, 0.91 ± 0.09, and 0.92 ± 0.09, respectively. Segmentation based on V-Net was similarly to that performed by experienced radiation oncologists. The CTV segmentation time was < 3.2 s, which could save the work time of clinicians. Conclusion V-Net is better than other models in CTV segmentation as indicated by quantitative metrics and clinician assessment. Additionally, the method is highly consistent with the ground truth, reducing inter-doctor variability and treatment time.
  • Original Articles
    YANG Jinzheng, FANG Jiangqi, ZHANG Wenfeng, LIU Linfeng, WU Mingyang, NIU Guochen
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    Objective To measure the air-absorbed dose rate of gamma radiation in public areas for the situation of the local radiation environment. Methods Using a large-volume γ spectrometer system with a NaI(Tl) detector mounted on a UAV, we conducted large-scale airborne radiation monitoring in public areas in southwestern China, to measure the air-absorbed dose rate at a height of 1 m from the earth’s surface. Results The airborne radiation monitoring data were used to analyze the local radiation environment. The mean air-absorbed dose rate at a height of 1 m was 43.6 ± 12.9 nGy/h. Seven abnormal radiation points were detected, and two of them were located where construction was ongoing. At one of the abnormal radiation points, FH40G meter measurements showed that the air-absorbed dose rate at a height of 1 m was up to 22.0 μGy/h. Field soil samples were collected for HPGe γ spectrometer analysis: the 232Th radionuclide activity concentration was 96.0 kBq/kg, and the 226Ra radionuclide activity concentration was 9.9 kBq/kg. Conclusion Using the UAV-mounted large-volume γ spectrometer system with NaI(Tl) detectors for large-scale airborne monitoring is a fast and effective method for dragnet monitoring of the level of radiation in public areas.
  • Original Articles
    XU Xiaosan, FENG Zechen, ZHAI Zipo, DU Xiang, YANG Chunyong, WANG Jin
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    Objective To track and evaluate the scientificity, applicability, and operability of the current implementation of the Radiation Shielding Specifications for Radiotherapy Treatment Rooms—Part 2: Radiotherapy Room of Electron Linear Accelerators (GBZ/T 201.2—2011) among personnel in medical radiation technology service institutions, and to provide scientific evidence for further improvement of the standard. Methods Following the Guidelines for Health Standards Tracking Evaluation Work (WS/T 536—2017) and the project implementation plan, a survey was conducted among 140 personnel engaged in shielding testing and evaluation of electron linear accelerator rooms in medical radiation technology service institutions from 24 provinces in China. The methods of pre-investigation, on-site research, mailing, and email were used to collect data for analysis. Results Questionnaires were completed by 140 respondents from 98 medical radiation service institutions, including 63 public institutions and 77 private institutions. Of the surveyed individuals, 86.68% claimed to have a good or very good understanding of the standard, while only 64.3% had participated in training related to the standard. The survey indicated a low level of mastery of the standard content among the personnel and insufficient efforts in training and dissemination. Although only 3.57% of the respondents considered the existing standard to be inapplicable in the context of new radiotherapy equipment and technological advancements, 95.71%, 93.57%, and 96.43% believed that shielding calculation examples should be added for tomotherapy devices, CyberKnife systems, and ring accelerators with self-shielding bodies. Furthermore, 65% of the respondents felt that neutron shielding should be considered for 10 MV X-ray accelerator rooms. Conclusion The GBZ/T 201.2—2011 has been widely used for radiation protection in radiotherapy. However, it is imperative to update this standard. Additionally, due to the technical complexity of the standard, it can be challenging for professionals to fully understand and implement it. Therefore, publicity goals should be tailored to different groups and the training of key personnel should be strengthened. A nationwide communication and cooperation mechanism should be established to ensure uniform implementation of the standard.
  • Original Articles
    LI Wei, YANG Yunfu, ZHAI Hezheng, LUO Hanghang, ZHANG Lilong, WEN Xiangmin, MA Yongzhong, YANG Chunyong
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    Objective To track and evaluate the implementation of the Radiation Shielding Requirements in Room of Radiotherapy Installations—Part 1: General Principle (GBZ/T 201.1–2007) among relevant personnel in medical radiation institutions, and to provide a scientific basis for revising the standard. Methods According to the Guidelines for Health Standards Tracking Evaluation (WS/T 536–2017) and the implementation protocol of standard evaluation, an online survey was conducted among 212 relevant workers from 146 medical radiation institutions across 18 provinces in China. The data were aggregated and analyzed with the use of Microsoft Excel 2010. Results A total of 215 questionnaires were returned, of which 212 were valid. Among the valid respondents, 77.8% believe that this standard is universally applied; 96.2% believe that this standard can meet work needs; 63.7% have participated in relevant training on this standard; 74.1% use this standard once or more per year; and 10.8% believe that this standard needs to be revised. Conclusion Medial radiation workers have a high rate of awareness of the basic information and content of the standard, but the understanding and application of the standard content need to be improved. We recommend that relevant departments further strengthen the promotion of and training on the standard, revise some content based on actual situation, and improve workers’ ability to use the standard.
  • Original Articles
    JIANG Shifeng, HUANG Lifang, LIU Ranran
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    Objective To understand the levels and trends of personal doses of occupational external exposure among radiation workers in medical institutions in Huizhou City and to improve radiation protection management. Methods Thermoluminescent dosimetry was employed to monitor the personal doses of occupational external exposure of radiation workers over monitoring cycles spanning three months each. Results From 2019 to 2023, a total of 25 796 monitoring instances were recorded for radiation workers in medical institutions in Huizhou City. Diagnostic radiology workers accounted for the largest proportion of workforce in the occupational categories, followed by interventional radiology workers. The average annual effective dose per person ranged from 0.21 to 0.30 mSv, with an average of 0.26 mSv. The majority of annual effective dose per person was below 1.0 mSv, with no instances exceeding 20 mSv. Among all occupational categories, nuclear medicine workers had the highest average annual effective dose per person at 0.43 mSv, followed by interventional radiology workers at 0.37 mSv. There was a significant difference in the average annual effective dose per person among different occupational categories (P < 0.05), with nuclear medicine and interventional radiology workers having higher doses than workers in diagnostic radiology, dental radiology, and other applications (all P < 0.05). Conclusion The personal dose monitoring results for radiation workers in medical institutions in Huizhou City are at low levels, indicating that the radiation protection in the local medical institutions is sufficient and can effectively protect the occupational health of radiation workers.
  • Original Articles
    LIU Xiaoyu, ZHANG Xiuyun, ZHANG Dong, WANG Guohua, CHE Zijing, LIU Zhenyou
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    Objective To provide data base for the development of X-ray computed tomography (CT) diagnostic reference levels suitable for the physical characteristics of residents in Qingdao City, China. Methods A total of 3351 cases of adult CT scan data derived from 14 devices were randomly selected from three tertiary hospitals and one primary hospital from January 1 to December 31, 2022. CT examination was performed on the brain, paranasal sinus, neck, chest, abdomen, cervical vertebrae, and lumbar vertebrae. The cases also included CT angiography (CTA) data on the brain, neck artery, pulmonary artery, and aorta. The data types included tube voltage (kV), effective tube current (mAs), computed tomography dose index volume (CTDIvol), and dose length product (DLP). The 1st, 2nd, 3rd quartile values of CTDIvol and DLP were calculated. Results Large differences were observed in DLP among different body parts of adults. The DLP value showed a descending order of craniocerebral CTA, craniocerebral CT, abdomen CT, lumbar vertebral spiral CT, aorta CTA, pulmonary artery CTA, paranasal sinus CT, chest CT, cervical vertebral spiral CT, and neck CT. The 3rd quartile DLP values of the brain and neck were 657.9 and 228.1 mGy·cm, respectively. The CTDIvol of the brain was largest (3rd quartile, 52.0 mGy) and the CTDIvol of the chest was smallest (3rd quartile, 8.2 mGy). Conclusion There are significant differences in CTDIvol and DLP between different body parts of adults in Qingdao City, and CT radiation dose levels are relatively low compared to other regions in China and other countries.
  • Original Articles
    ZHAI Aihua, NING Guoying, XIN Jiangbo, QIN Yiwen, GU Yujiang
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    Objective To investigate the exposure level of radioactive hazard factors and the health management of radiation workers in non-medical radiation institutions (excluding military institutions) in Jinan, China through radioactive hazard factor monitoring, to identify the weak links, and to provide a scientific basis for future work priorities. Methods According to the monitoring plan formulated by Jinan Municipal Health Commission, the task undertaking institutions at all levels in Jinan investigated the types of radioactive hazard factors, detection, training, and health monitoring of 101 non-medical radiation institutions in Jinan. In addition, the workplace radiation levels were detected in 25 institutions of 6 types of monitoring objects, including industrial flaw detection, non-medical accelerator, non-sealed radioactive material workplace, nuclear instrument, baggage detector, and others. Results The investigation objects included institutions engaged in industrial flaw detection, nuclear instrument, luggage detector, non-medical accelerator, non-sealed source workplace, and others. Of these institutions, 91.84% were equipped with radiation protection detectors, 92.86% were equipped with personal dose alarm, 97.73% were equipped with personal protective equipment, 94.36% performed radiation protection training, 92.69% employed radiation workers with certificates, 95.77% performed personal dose detection, 94.83% performed occupational health examination, and 100.00% were qualified for radiation protection detection in workplace. Conclusion There is still a gap between the radiation protection status of non-medical institutions in Jinan and the national regulations and standards, so it is necessary to further strengthen supervision and law enforcement and make greater efforts in training and publicity.
  • Original Articles
    FU Zhenzhen, LING Yunshan
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    Conducting comprehensive and in-depth analysis, summarizing findings, and learning lessons from past accidents is a powerful means to prevent their recurrence. In this paper, we summarize a case of acute radioactive skin injury accident caused by industrial flaw inspection. We analyze the main causes of radiation accidents and discuss the problems existing in mobile radioactive source management from multiple perspectives. We put forward practical measures and suggestions to avoid or reduce the occurrence of similar accidents. Our findings contribute to the protection of the radiation health and safety of radiation workers and the public.
  • Original Articles
    GAO Xingxing, HUI Hui, REN Hongrong, ZHOU Yun
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    Objective To explore the radiosensitizing effect of arsenic trioxide (ATO) in cervical cancer, and to further explore the underlying mechanism related to DNA damage repair. Methods Human cervical cancer cells (Siha and Hela cells) were cultured in vitro, treated with different concentrations of ATO, and the cell proliferation was detected by CCK-8 assay. The cells were divided into four groups: control group, radiotherapy (IR) group, ATO group, and radiotherapy + ATO (IR + ATO) group. Radiosensitization ratio was determined by plate cloning assay, cell cycle and apoptosis by flow cytometry, the expression of γH2AX by immunofluorescence, the expression of Cyclin B1, PTEN, and RAD51 by Western blot, and the expression of RAD51 mRNA by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Results CCK-8 showed that ATO at concentrations of 1 μM and higher could significantly inhibit the proliferation of Siha and HeLa cells. Plate cloning showed that ATO had a radiosensitizing effect on cervical cancer, and the radiosensitization ratios were 1.37 and 1.30, respectively. Flow cytometry showed that the proportion of cell cycle arrest was significantly higher in the IR + ATO group than that in the control group (P < 0.001). The apoptosis rate was significantly higher in the IR + ATO group than that in the control group (P < 0.01). Western blotting showed that the expression levels of PTEN and RAD51 proteins significantly decreased (P < 0.05) and the expression level of Cyclin B1 protein significantly increased (P < 0.05) in the IR + ATO group. Conclusion ATO achieves radiosensitization in cervical cancer through blocking the DNA homologous recombination repair pathway by consuming PTEN.
  • Original Articles
    ZHOU Lijuan, WEN Yongcang, ZHANG Gensheng, SHI Wei, XIE Youyang, ZHANG Quancheng, ZHONG Jingsong, CHU Wei
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    Objective To analyze the magnetic resonance images (MRI) of patients with spinal epidural lipomatosis (SEL) in high-altitude areas and to determine the optimal cut-off value for diagnosis with epidural fat thickness. Methods This retrospective study included patients who underwent lumbosacral MRI examination for lumbosacral pain in Ping’an District Hospital of Traditional Chinese Medicine, Haidong City, China from January 1, 2021 to December 31, 2022. The epidural fat thickness in vertebral segments T12/L1 to L5/S1 was compared between the SEL group and the non-SEL group. The diagnostic efficacy with different cut-off values at each vertebral segment was evaluated. Between-group comparisons were performed using the t-test, Mann-Whitney U test, chi-square test, or modified chi-square test. The area under the receiver operating characteristic (AUC) was used to evaluate the diagnostic efficiency. The DeLong test was used to compare AUC between the two groups. Results A total of 370 patients were included (60 in the SEL group and 310 in the non-SEL group). There were no significant differences in age, sex, height, body weight, and body mass index between the two groups (all P > 0.05). At different vertebral segments, the epidural fat thickness was significantly higher in the SEL group than in the non-SEL group (all P < 0.05). The cut-off values for SEL diagnosis with epidural fat thickness in segments T12/L1 to L5/S1 were 2.23, 4.25, 4.85, 5.57, 7.21, and 8 mm, respectively. The AUC of MRI SEL diagnosis with epidural fat thickness in segment L5/S1 was the highest (0.945, 95% confidence interval [CI]: 0.916-0.966, P < 0.001). SEL diagnosis with epidural fat thickness > 8 mm in segment L5/S1 was the most accurate, with an AUC of 0.931 (95% CI: 0.901-0.955, P < 0.001), a sensitivity of 95.0%, and a specificity of 91.3%; this AUC was significantly higher than those of diagnosis with other cut-off values (all P < 0.05). Conclusion SEL patients have significantly increased epidural fat in the spinal canal. Epidural fat thickness > 8 mm in segment L5/S1 can be used for diagnosis of SEL with improved efficiency and accuracy.
  • Original Articles
    YUE Haizhen, YOU Jing, WU Hao, JIANG Xiaoyan, CHENG Jinsheng, DING Kuke
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    Objective To investigate the clinical characteristics and dosimetric parameters associated with acute hematologic toxicity (AHT) resulting from radiation-induced damage to hematopoietic organs in patients undergoing chemoradiotherapy for cervical cancer and to provide a reference for establishing dose constraints in relevant regions of interest (ROIs) and predicting adverse tissue reactions during the development of clinical treatment plans. Methods A retrospective analysis was conducted on 556 patients with cervical cancer who underwent chemoradiotherapy at our hospital. Univariate (χ2 and t-test) and multivariate (binary logistic regression analyses) methods were employed to investigate the association of clinical factors and pelvic dose-volume parameters with grade ≥ 3 AHT in patients with cervical cancer. Clinical factors comprised patients’ age, clinical stage, pathologic stage, whether the patient had received chemotherapy in the radiotherapy cycle of interest, and dose-volume dosimetric parameters Vx and Dmean for pelvic bone marrow (BM) and femoral head (FH) structures. Results The incidence of AHT among the included cases was 30.4% (169/556). Chi-square analysis of the clinical factors revealed that whether the patient had received chemotherapy, patient’s age, and pathologic stage had a significant impact on AHT. Univariate analysis showed that the factors associated with AHT were mean dose, V5, V10, V15, V20, and V25 of BM and FH; dosimetric parameters such as V35 of FH had a significant impact on the development of AHT. Multivariate logistic regression analysis identified V15 of pelvic BM as an independent risk factor for AHT (P=0.041), with a threshold value of 84.29% as determined by a receiver operating characteristic (ROC) curve. Conclusion Whether a patient had received chemotherapy in the radiotherapy cycle of interest, and patient’s age and pathologic stage can serve as predictors of AHT. V15 of BM is an independent risk factor for AHT development. Therefore, when formulating a treatment plan, it is crucial to ensure that pelvic V15 remains below 84.29% to effectively reduce the incidence of grade ≥ 3 acute bone marrow depression.
  • Original Articles
    LI Yang, LIU Mengyu, YIN Ping, LI Yue, ZHU Chenjing, LIN Li, ZHANG Siyu, SUN Zhihua, XU Hanzi
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    Objective To investigate the clinical application of three-dimensional intracavitary/free-hand interstitial brachytherapy technique in radical radiotherapy for cervical cancer. Methods A retrospective study was conducted on the clinical data of patients with cervical cancer who underwent radical radiotherapy using CT-guided three-dimensional intracavitary/free-hand interstitial brachytherapy technique in The Affiliated Cancer Hospital of Nanjing Medical University from April 2019 to September 2021. The short-term efficacy and adverse reactions were analyzed, and the independent predictors affecting short-term efficacy were evaluated by logistic risk regression model. Results A total of 182 patients were included, and all patients successfully completed the treatment. Clinical efficacy assessment performed 3 months after treatment revealed an overall response rate of 90.65%; the incidence of grade 3 and 4 adverse reactions in the lower gastrointestinal tract was 4.4% during treatment. After reclassifying stage IIIC patients according to the International Federation of Gynecology and Obstetrics (FIGO) 2009 staging system and including factors affecting the stage, it was found that the tumor volume before brachytherapy was the main factor affecting the clinical efficacy of patients at this stage (P = 0.004). Conclusion As a key method in radical radiotherapy for cervical cancer, three-dimensional intracavitary/free-hand interstitial brachytherapy technique is safe and effective and can be quickly popularized in primary hospitals beyond regional cancer centers for cervical cancer brachytherapy.
  • Original Articles
    CHEN Suo, JIANG Heli, XU Jiang
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    Objective To compare the value of low-dose spiral CT and conventional-dose CT for diagnosis of benign and malignant pulmonary nodules, so as to provide a reference for early screening of lung cancer. Methods A total of 288 patients diagnosed with pulmonary nodules in Ningguo Municipal People’s Hospital during the period from January 2019 to August 2023 were enrolled, and all patients underwent low-dose chest spiral CT and conventional-dose CT scans. The pathological biopsy of pulmonary nodules served as a gold standard. The sensitivity, specificity, and accuracy of low-dose spiral CT and conventional-dose CT for diagnosis of benign and malignant pulmonary nodules and the detection rates of vascular aggregation sign, pleural indentation sign, lobulation sign, and spiculation sign were compared. Results The 288 patients with pulmonary nodules included 186 men and 102 women, with a mean age of 61.12 ± 8.34 years. Among these patients, 218 had benign pulmonary nodules and 70 had malignant pulmonary nodules. There were no significant differences between patients with benign and malignant pulmonary nodules in terms of sex, mean age, and the size, location, and characteristics of pulmonary nodules (all P values > 0.05). However, significant differences were observed in terms of changes in pulmonary nodule size, history of smoking, history of pulmonary infections, and family history of cancers (all P values < 0.05). With pathological biopsy of pulmonary nodules as a gold standard, the sensitivity, specificity, and accuracy of conventional-dose CT and low-dose spiral CT for diagnosis of benign and malignant pulmonary nodules were 94.29% and 92.86%, 93.57% and 92.20%, and 93.75% and 92.36%, respectively, with no significant differences (χ2 = 1.975, 1.012, and 1.911, all P values > 0.05). There was no significant difference in the area under the receiver operating characteristic curve between conventional-dose CT and low-dose spiral CT (0.937 vs. 0.921; t = 1.021, P > 0.05). The detection rates of vascular aggregation sign, pleural indentation sign, lobulation sign, and spiculation sign were 20.49% and 19.79%, 23.26% and 22.57%, 37.50% and 35.76%, and 29.17% and 27.43%, respectively, for conventional-dose CT and low-dose spiral CT, with no significant differences (χ2 = 0.171, 0.212, 1.012, and 1.110, all P values > 0.05). Conclusion The diagnostic sensitivity, specificity, and accuracy of benign and malignant pulmonary nodules and the detection rate of pulmonary nodule signs are comparable between conventional-dose CT and low-dose spiral CT. However, low-dose spiral CT has lower radiation dose and higher safety, which deserves extensive applications in early screening for lung cancer.
  • Original Articles
    ZHANG Liwei, YUAN Guiping, FANG Juanjuan, TENG Minmin, SONG Dewei, YU Bo, SHAO Yuanwei
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    Objective To investigate the correlations of computed tomography (CT), clinical, and pathological features in patients with invasive lung adenocarcinoma positive and negative for spread through air spaces (STAS). Methods A total of 236 patients with invasive lung adenocarcinoma confirmed by surgery and pathology were selected, including 118 patients in STAS-positive group and 118 patients in STAS-negative group. The clinical data, CT signs, and pathological features of the two groups were collected and analyzed. Results There was a correlation between age and the occurrence of STAS. The age of the positive group was higher than that of the negative group. Smoking history and family history of tumor had no correlation with the occurrence of STAS. CT features signs such as nodule type and shape, tumor-lung interface, lobulation sign, spiculation sign, vacuole/cavity, air-bronchogram, pleural indentation sign, vascular changes, mean diameter of tumor, mean diameter of solid component, and the percentage of tumor solid components were significantly different between patients with and without STAS. The incidence of STAS in patients with solid nodules and partial solid nodules was significantly higher than that in patients with ground glass nodules. Multivariate analysis showed that the percentage of tumor solid components, air-bronchogram sign, lobulation sign, and tumor-lung interface were independent risk factors for predicting the occurrence of STAS. Conclusion The clinical data and CT signs of patients with invasive lung adenocarcinoma are related to the occurrence of STAS. CT signs such as the percentage of tumor solid components, air-bronchogram, lobulation sign, and tumor-lung interface are of great significance to STAS prediction. Our findings provide an important basis for selection of personalized clinical treatment plans.
  • Review Articles
  • Review Articles
    FENG Zechen, WANG Zihan, MA Yongzhong, XU Hui, MA Qiao, LI Hailiang
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    kV X-ray radiotherapy was the primary mode of radiotherapy widely used to treat many types of cancer, including deep tumors, before the invention of the Co-60 therapy machine and the electron linear accelerator, which gradually replaced kV X-ray radiotherapy. kV X-ray radiotherapy equipment requires less space and shielding, and still has application value in the treatment of skin lesions and superficial tumors. Especially in recent years, kV X-ray has been used in the treatment of keloid, and electronic brachytherapy equipment has been used in intracavitary, intraoperative, and superficial radiotherapy. Therefore, kV X-ray radiotherapy has seen renewed application. The quality control of kV X-ray radiotherapy equipment is the key to ensure the treatment effect and safety of patients. This paper reviews the current status of quality control of kV X-ray radiotherapy equipment and provides a reference for the formulation of quality control assessment standards for kV X-ray radiotherapy equipment.
  • Review Articles
    KANG Yanru, SONG Jialin, LYU Wencheng, ZHANG Hua
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    Mediastinal lymph node metastasis is a common metastasis pathway of non-small cell lung cancer (NSCLC), and its occurrence is closely related to lymphatic drainage pattern. NSCLC in different pulmonary lobes requires different lymphatic drainage patterns, which poses a challenge for the formulation of individualized treatment strategies. Accurate staging is the prerequisite for precision treatment of NSCLC. Computed tomography (CT) examination is an important tool for evaluating mediastinal lymph node metastasis, which is crucial for making treatment plan and evaluating patient prognosis. However, it is difficult to diagnose metastatic lymph nodes with insignificant imaging features, especially metastatic lymph nodes in zone 4 and zone 7, which are hot spots for mediastinal lymph node metastasis. However, clinical guidelines do not make clear provisions on lymph node dissection in zone 4, which makes preoperative clinical staging and prognosis evaluation of patients with NSCLC particularly important. By integrating and analyzing a large amount of data in CT images, the emerging CT radiomics technology captures subtle features that may be overlooked in conventional CT scans, showing great application prospects in improving the accuracy of non-invasive diagnosis of lymph node metastasis. This review aims to explore the mediastinal drainage pattern and the role of CT in evaluating mediastinal lymph node metastasis, in order to provide valuable imaging evidence for accurately judging mediastinal lymph node metastasis of NSCLC, formulating appropriate lymph node dissection scope, optimizing treatment strategy, and improving patient prognosis.
  • Review Articles
    ZHANG Yue, ZENG Furong, LI Xiaogang
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    As the clinically most common endocrine system disease, thyroid disorder is a global health problem characterized by high incidence and high disease burden. Currently, surgery remains the standard treatment of most thyroid cancers; however, active surveillance remains a feasible option for treatment of low-risk thyroid disorders. As the currently most widely used approach of thermal ablation, radiofrequency ablation is a safe and effective treatment for a variety of thyroid disorders. The review presents the advances in the efficacy and complications of radiofrequency ablation for treatment of benign thyroid nodules, follicular thyroid adenoma, and primary and recurrent thyroid cancers.
  • Review Articles
    LINGHU Renjing, ZHANG Jing, LIANG Runcheng, CHEN Faguo, ZHAO Ri, LIU Xin
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    Compared with conventional radiotherapy fields, small field has unique dosimetry characteristics such as high dose gradient, charged particle imbalance, and dose effect caused by source occlusion. These characteristics increase the difficulty of dose measurement and thus the uncertainty of clinical dose measurement, far exceeding the requirement of < 5% measurement error in ICRU 24 report. In recent years, with the development of new radiotherapy technologies, the minimum radiotherapy field can reach the millimeter level, and the single irradiation dose of hypofractionated radiotherapy can exceed 6 Gy. The larger dose gradient at the edge of radiotherapy field requires higher accuracy of dose measurement, and accurate small field dosimetry technologies have gradually become a research hotspot in the field of precision radiotherapy. In order to ensure the high accuracy of measurement, this paper reviews the research on small field dosimetry worldwide, and summarizes the key points of small field dosimetry. In this paper, the characteristics of small field dosimetry are introduced, and the current small field dosimetry technologies and optimization methods are summarized, including the optimization of detector selection and detector sensitive volume. The field output correction factor technologies are analyzed. In view of the difficulty in small field dosimetry, this paper provides suggestions on dosimetry based on clinical needs and the characteristics of medical linear accelerators. Our suggestions provide a scientific reference for small field dosimetry in clinical practice in radiotherapy institutions, and facilitate the development of radiotherapy dose verification.