1.Construction of Saikosaponin D Multifunctional Liposomes and Evaluation of Its Anti-liver Cancer Efficacy and Targeting
Kun YU ; Guochun YANG ; Yaliang JIANG ; Yunting XIAO ; Congxian WANG ; Qionge SUN ; Ziyue LI ; Yikun SHANG ; Yu MAO ; Xin CHENG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(9):205-216
ObjectiveTo construct a multifunctional liposomal delivery system by replacing cholesterol(Chol) in conventional liposomes with saikosaponin D(SSD) and modifying with poloxamer 407(P407) for co-delivery of curcumin(Cur). The system was evaluated for in vivo tumor targeting and inhibitory effects on mouse subcutaneous solid tumors. MethodsSingle-factor and orthogonal tests combined with information entropy weighting were used to optimize the formulation process of the liposome with encapsulation efficiency and absolute Zeta potential as indexes, and validation studies and liposomal characterization were performed. A subcutaneous solid tumor model was established by injecting H22 hepatocellular carcinoma cells subcutaneously into the dorsal surface of the right forelimb of mice. DiR-loaded traditional Chol liposomes(P407-DiR-Chol-LPs, PDCL) and novel SSD-based liposomes(P407-DiR-SSD-LPs, PDSL) were prepared by the optimized formulation process, and tail vein injection was performed to investigate the impact of SSD on liposome tumor targeting with small animal in vivo imaging. Mice were randomly divided into eight groups, including blank group, model group, free doxorubicin(DOX) group(2 mg·kg-1), free Cur group(8 mg·kg-1), free SSD group(10 mg·kg-1), P407-Cur-Chol-LPs(PCCL) group, P407-SSD-LPs(PSL) group, and P407-Cur-SSD-Lps(PCSL) group. Treatments were administered intraperitoneally every other day for seven doses. Antitumor efficacy and biocompatibility were evaluated by monitoring body weight change, organ indices, tumor volume and mass, relative tumor proliferation rate(T/C), and tumor growth inhibition rate(TGI). Histopathological analysis of liver, kidney, and tumor tissues was performed using hematoxylin-eosin(HE) staining. Serum levels of aspartate aminotransferase(AST), alanine aminotransferase (ALT), blood urea nitrogen(BUN), and creatinine(Crea)in mice were quantified by fully automated biochemical analyzer. ResultsOrthogonal test yielded optimal ratios of Cur, SSD, and P407 to soybean phosphatidylcholine(SPC) as 1∶25, 1∶20, and 1∶4. The optimized PCSL exhibited spherical morphology with a particle size of 179.15 nm, a Zeta potential of -47.25 mV, and an encapsulation efficiency of 96.40%. Its in vitro release profile conformed to first-order kinetics, demonstrating excellent storage stability and hemocompatibility. In vivo imaging revealed that the fluorescence signal in tumor tissues and the fluorescence intensity ratio between tumors and organs were significantly higher in the PDSL group than in the PDCL group(P<0.05, P<0.01). Among the treatment groups, PCSL group showed superior efficacy over free Cur group, free SSD group, PCCL group, and PSL group, with TGI>40% and T/C<60%, indicating pronounced anti-hepatocellular carcinoma effects(P<0.05, P<0.01). Histopathology and serum biochemistry indicated minimal hepatorenal toxicity and improved hepatic and renal function in PCSL-treated mice. ConclusionReplacing Chol with SSD in preparing multifunctional drug delivery systems not only stabilizes liposomes but also yields superior anti-hepatocellular carcinoma efficacy, achieving the effect of drug-excipient integration. Co-delivery of Cur via this system can be used for treating subcutaneous solid tumors in hepatocellular carcinoma, providing new insights and technical approaches for anti-hepatocellular carcinoma research and the meridian-guiding and messenger-directing theory in traditional Chinese medicine.
2.Research progress and clinical challenges in immunosuppressive regimens for xenotransplantation
Yu ZHANG ; Kun WANG ; Xuyuan ZHU ; Yuxiang CHEN ; Tao LI ; Xiaojie MA ; Hongtao JIANG
Organ Transplantation 2026;17(1):28-35
As a pivotal strategy to alleviate the shortage of organ donors, xenotransplantation has achieved remarkable advances in both pre-clinical and clinical studies in recent years, driven by continuous optimization of gene modification techniques and immunosuppressive regimens. Nevertheless, clinical translation still confronts formidable challenges, including rejection and heightened infection risks, which severely compromise long-term graft survival. Consequently, the role of immunosuppressive regimens in xenotransplantation has become increasingly prominent. This article summarizes the mechanisms underlying xenogeneic immune rejection, the latest developments in immunosuppressive regimens, cutting-edge strategies for inducing immune tolerance and the major hurdles facing clinical xenotransplantation. It delves into potential optimization strategies and directions for future clinical research, aiming to offer theoretical insights and practical guidance for the safe and effective application of clinical xenotransplantation.
3.Optimization of Ovarian Tissue Vitrification Using Hydrogel Encapsulation and Magnetic Induction Nanowarming
Yu-Kun CAO ; Na YE ; Zheng LI ; Xin-Li ZHOU
Progress in Biochemistry and Biophysics 2025;52(2):464-477
ObjectiveFor prepubertal and urgently treated malignant tumor patients, ovarian tissue cryopreservation and transplantation represent more appropriate fertility preservation methods. Current clinical practices often involve freezing ovarian tissue with high concentrations of cryoprotectants (CPAs) and thawing with water baths. These processes lead to varying degrees of toxicity and devitrification damage to ovarian tissue. Therefore, this paper proposes optimized methods for vitrification of ovarian tissues based on sodium alginate hydrogel encapsulation and magnetic induction nanowarming technology. MethodsFirstly, the study investigated the effects of sodium alginate concentration, the sequence of hydrogel encapsulation and CPAs loading on vitrification efficiency of encapsulated ovarian tissue. Additionally, the capability of sodium alginate hydrogel encapsulation to reduce the required concentration of CPAs was validated. Secondly, a platform combining water bath and magnetic induction nanowarming was established to rewarm ovarian tissue under various concentrations of magnetic nanoparticles and magnetic field strengths. The post-warming follicle survival rate, antioxidant capacity, and ovarian tissue integrity were evaluated to assess the efficacy of the method. ResultsThe study found that ovarian tissue encapsulated with 2% sodium alginate hydrogel exhibited the highest follicle survival rate after vitrification. The method of loading CPAs prior to encapsulation proved more suitable for ovarian tissue cryopreservation, effectively reducing the required concentration of CPAs by 50%. A combination of 8 g/L Fe3O4 nanoparticles and an alternating magnetic field of 300 Gs showed optimal warming effectiveness for ovarian tissue. Combining water bath rewarming with magnetic induction nanowarming yielded the highest follicle survival rate, enhanced antioxidant capacity, and preserved tissue morphology. ConclusionSodium alginate hydrogel encapsulation of ovarian tissue reduces the concentration of CPAs required during the freezing process. The combination of magnetic induction nanowarming with water bath provides an efficient method ovarian tissue rewarming. This study offers novel approaches to optimize ovarian tissues vitrification.
4.Ursodeoxycholic acid inhibits the uptake of cystine through SLC7A11 and impairs de novo synthesis of glutathione
Fu'an XIE ; Yujia NIU ; Xiaobing CHEN ; Xu KONG ; Guangting YAN ; Aobo ZHUANG ; Xi LI ; Lanlan LIAN ; Dongmei QIN ; Quan ZHANG ; Ruyi ZHANG ; Kunrong YANG ; Xiaogang XIA ; Kun CHEN ; Mengmeng XIAO ; Chunkang YANG ; Ting WU ; Ye SHEN ; Chundong YU ; Chenghua LUO ; Shu-Hai LIN ; Wengang LI
Journal of Pharmaceutical Analysis 2025;15(1):189-207
Ursodeoxycholic acid(UDCA)is a naturally occurring,low-toxicity,and hydrophilic bile acid(BA)in the human body that is converted by intestinal flora using primary BA.Solute carrier family 7 member 11(SLC7A11)functions to uptake extracellular cystine in exchange for glutamate,and is highly expressed in a variety of human cancers.Retroperitoneal liposarcoma(RLPS)refers to liposarcoma originating from the retroperitoneal area.Lipidomics analysis revealed that UDCA was one of the most significantly down-regulated metabolites in sera of RIPS patients compared with healthy subjects.The augmentation of UDCA concentration(≥25 μg/mL)demonstrated a suppressive effect on the proliferation of liposarcoma cells.[15N2]-cystine and[13Cs]-glutamine isotope tracing revealed that UDCA impairs cystine uptake and glutathione(GSH)synthesis.Mechanistically,UDCA binds to the cystine transporter SLC7A11 to inhibit cystine uptake and impair GSH de novo synthesis,leading to reactive oxygen species(ROS)accumulation and mitochondrial oxidative damage.Furthermore,UDCA can promote the anti-cancer effects of ferroptosis inducers(Erastin,RSL3),the murine double minute 2(MDM2)inhibitors(Nutlin 3a,RG7112),cyclin dependent kinase 4(CDK4)inhibitor(Abemaciclib),and glutaminase inhibitor(CB839).Together,UDCA functions as a cystine exchange factor that binds to SLC7A11 for antitumor activity,and SLC7A11 is not only a new transporter for BA but also a clinically applicable target for UDCA.More importantly,in combination with other antitumor chemotherapy or physiotherapy treatments,UDCA may provide effective and promising treatment strategies for RLPS or other types of tumors in a ROS-dependent manner.
5.Influence of helical tomography radiotherapy planning parameters on threading effect
Ruo-qi CAO ; Xia-yu HANG ; Hua HUANG ; Xian-qiang SONG ; Jin-da ZHOU ; Yun-jie BAI ; Xiang-dong SUN ; Yi-kun LI
Chinese Medical Equipment Journal 2025;46(8):58-66
Objective To investigate the influence of helical tomographic radiotherapy plans with different combinations of lead gate width,pitch and algorithms on threading effects.Methods A target model was established with a Cheese Phantom used as the simulated human body,then three lead gate widths(1.0,2.5,and 5.0 cm),six screw pitches(0.143,0.172,0.215,0.287,0.430,and 0.500)and two computational grids(Fine algorithm and Normal algorithm)were respectively combined for designing the helical tomography radiotherapy plans.The radiotherapy plans with a pitch of 0.143,0.172,0.215,0.287 or 0.430 were enrolled into an experimental group,and the plans with a pitch of 0.500 were divided into a control group.The dosimetric parameters including maximum dose(Dmax),minimum dose(Dmin)and mean dose(Dmean)of the target area PTV1 and PTV2 were evaluated by the dose volume histogram(DVH).The dose homogeneity index(HI)of the target area was calculated,and the single rotation time and total treatment time of each plan were recorded and counted.SPSS 27.0 software was used for statistical analysis.Results No significant threading effect appeared regardless of the pitch value when the lead gate width was 1.0 cm.The threading effects in the experimental group were weaker than those in the control group when the lead gate width was 2.5 or 5.0 cm.The threading effect gradually rose with the pitch increased when the lead gate width was 5.0 cm.The most significant difference was found between the threading effect in case of the screw pitch being 0.500 and that with the screw pitch being 0.143,with the differenes being statistically obvious(P<0.05).The lead gate width had significant effects on the Dmax,Dmin,Dmean and HI of PTV1 and PTV2.When the lead gate width was 5.0 cm,high HI value and uneven dose distribution were detected and lowered screw pitch weakened the threading effect.The single rotation time first remained constant and then increased with the screw pitch was enlarged,with the changing points occurring in case of the screw pitches of 0.287 and 0.430.With a certain lead gate width,the treatment time for plans was shortened with the decrease of the pitches in case of the pritches lower than 0.287,and tended to be constant after the screw pitches reached 0.287.The changes of the computational grid had no significant effects on the results of radiotherapy plans when the lead gate width and screw pitch were kept constant.Conclusion When designing a spiral tomotherapy plan with conventional doses,a lead gate width of 1.0 or 2.5 cm and a screw pitch of 0.287 or 0.430 should be selected in order to minimize the threading effect while ensuring the efficiency of plan implementation.[Chinese Medical Equipment Journal,2025,46(8):58-66]
6.Clinicopathological features and prognostic analysis of alpha-fetoprotein-producing gastric cancer
Yu ZHU ; Shuanglin HAN ; Kun GUO ; Li YING
Chinese Journal of Digestion 2025;45(7):450-456
Objective:To explore the clinicopathological features of serum alpha-fetoprotein-producing gastric cancer (AFPGC) and its subtype hepatoid adenocarcinoma of the stomach (HAS), and to analyze the related factors affecting the prognosis of AFPGC and HAS patients.Methods:The clinical data of 91 patients with AFPGC who were admitted to the Second Affiliated Hospital of Dalian Medical University from February, 2010 to February, 2021 were retrospectively collected. According to the results of hepatoid differentiation, the patients were divided into HAS group (26 cases) and non-HAS group (65 cases). Meanwhile, 130 patients with alpha-fetoprotein (AFP) negative gastric cancer at the Second Affiliated Hospital of Dalian Medical University were selected by stratified sampling method as common gastric cancer group. The clinicopathological data of patients in the HAS group, non-HAS group and common gastric cancer group were compared and all the patients were followed up for 3 years. Kaplan-Meier survival curves were plotted, and log-rank test was used to analyze the median survival time. Multivariate Cox regression was performed to analyze the independent risk factors affecting the prognosis of patients. Chi-square test was used for statistical comparison.Results:The proportion of patients with poorly differentiated tumor in the HAS group was higher than that in the non-HAS group (84.6%(22/26) vs. 55.4%(36/65)), and the difference was statistically significant ( χ2=7.02, P=0.030). The proportions of patients with age < 60 years old, abnormal level of carcinoembryonic antigen (CEA), vascular tumor thrombus, liver metastasis, poor differentiated tumor, and postoperative chemotherapy in the HAS group were higher than those in the common gastric cancer group (34.6% (9/26) vs. 13.8% (18/130), 26.9% (7/26) vs. 7.7% (10/130), 73.1% (19/26) vs. 51.5% (67/130), 30.8% (8/26) vs. 11.5% (15/130), 84.6% (22/26) vs. 37.7% (49/130), and 69.2% (18/26) vs. 27.7% (36/130), respectively), and the differences were all statistically significant ( χ2=5.16, 6.39, 4.06, 4.94, 18.73, and 16.52; all P<0.05). The proportion of male patients in the non-HAS group was lower than that in the common gastric cancer group (58.5%(38/65) vs. 73.1%(95/130)), while the proportions of patients with age < 60 years old, abnormal levels of carbohydrate antigen (CA)15-3, CA19-9, CA242, and CEA in the non-HAS group were higher than those in the common gastric cancer group (40.0% (26/65) vs. 13.8%(18/130), 7.7%(5/65) vs. 0, 23.1%(15/65) vs. 10.0%(13/130), 18.5%(12/65) vs. 7.7%(10/130), and 23.1%(15/65) vs. 7.7%(10/130), respectively), and the differences were all statistically significant ( χ2=4.27, 16.69, 11.25, 6.03, 5.02, and 9.18; all P<0.05). The proportion of patients with maximum diameter of tumor ≥ 5 cm, clinical stage Ⅲ or Ⅳ, lymph node metastasis, extrahepatic metastasis, and postoperative chemotherapy in the non-HAS group were all higher than those in the common gastric cancer group (58.5% (38/65) vs. 42.3% (55/130), 64.6% (42/65) vs. 46.2% (60/130), 83.1% (54/65) vs. 54.6% (71/130), 47.7% (31/65) vs. 15.4% (20/130), and 75.4% (49/65) vs. 27.7% (36/130), respectively), and the differences were all statistically significant ( χ2=4.53, 10.80, 15.26, 23.41, and 40.08; all P<0.05). The incidence of liver metastasis in patients with AFP >100 μg/L was higher than that in patients with AFP ≤100 μg/L (47.6%(10/21) vs. 17.1%(12/70)), and the difference was statistically significant ( χ2=8.18, P=0.004). The results of Kaplan-Meier survival analysis showed that the median survival time of patients in the HAS group, non-HAS group and common gastric cancer group was 13, 28, and 54 months, respectively, and the difference was statistically significant (log-rank test, χ2=20.33, P<0.001). The results of multivariate Cox regression analysis revealed that CA19-9 ( HR=5.803, 95% confidence interval (95% CI): 1.545 to 21.794, P<0.001) and extrahepatic metastasis ( HR=2.747, 95% CI: 1.243 to 6.068, P=0.012) were independent risk factors affecting the prognosis of patients in the non-HAS group. CA15-3 ( HR=84.163, 95% CI: 5.085 to 1 392.920, P=0.002), CA125 ( HR=0.038, 95% CI: 0.006 to 0.257, P=0.001), and the degree of tumor differentiation ( HR=2.284, 95% CI: 1.101 to 36.677, P=0.039) were independent risk factors affecting the prognosis of patients in the HAS group. Conclusions:Compared to common gastric cancer, AFPGC is characterized by advanced clinical stages, with higher propensity for lymph node metastasis, liver metastasis, extrahepatic metastasis and poor prognosis. The higher the AFP level before surgery, the more possibility of liver metastasis after surgery. Serum CA15-3 and CA125 might be tumor markers in predicting the prognosis of HAS patients.
7.Astrocytes regulate remyelination in central nervous system
Jing SHUI ; Yu HE ; Nan JIANG ; Kun XU ; Lijuan SONG ; Zhibin DING ; Cungen MA ; Xinyi LI
Chinese Journal of Tissue Engineering Research 2025;29(36):7889-7897
BACKGROUND:Remyelination in the central nervous system is a basic repair process triggered by demyelinating events,mainly through the proliferation,migration,and differentiation of oligodendrocyte precursor cells into oligodendrocytes.The process of remyelination is affected by many factors such as astrocytes,myelin debris,microglia,macrophages,endothelial cells,pericytes,T cells,and age.OBJECTIVE:Astrocytes play an important role in regulating synaptic activity,nutritional support,and tissue repair in the central nervous system.This review aims to provide potential therapeutic targets for demyelinating diseases of central nervous system by reviewing the role of astrocytes in remyelination.METHODS:A search was conducted on relevant literature collected from CNKI,PubMed,and Web of Science from 2014 tO 2024.The search terms were"astrocytes,oligodendrocyte precursor cells,remyelination"in both Chinese and English.Finally,66 articles were included after screening and summarized.RESULTS AND CONCLUSION:(1)The treatment of demyelinating diseases,such as multiple sclerosis,is limited to disease-modifying therapies,and there is no available method to overcome the failure of remyelination.Therefore,it is necessary to explore targets related to remyelination to promote myelin repair.(2)Remyelination is a process in which oligodendrocyte precursor cells proliferate,migrate,differentiate,and mature into oligodendrocytes,and the latter produce myelin to wrap axons to form myelin sheath.(3)Astrocytes regulate remyelination by phagocytosis of myelin debris,participating in inflammatory response,transforming into oligodendrocyte lineage cells,providing energy supply for oligodendrocyte lineage cells,releasing neurotrophic factors,and secreting extracellular matrix components.(4)The drugs screened in this paper use astrocytes and their derived factors as intervention targets to regulate the remyelination.Some drugs have satisfactory effects,but their effectiveness and safety still need more basic research and clinical trials to verify.(5)The mechanism of action of astrocytes in remyelination has not been fully elucidated,and the related molecular targets and signaling pathways can be further studied.
8.Symptoms and quality of life benefits of successful percutaneous coronary intervention in left main disease and/or 3-vessel disease patients with diabetes
Bo-da ZHU ; Tian-tong YU ; Peng HAN ; Bo-hui ZHANG ; Xi ZHANG ; Ping YUAN ; Gang WANG ; Yi YANG ; Hui-li ZHU ; Pan-pan SUN ; Tong-tong LI ; Shuai ZHAO ; Cheng-xiang LI ; Kun LIAN
Chinese Journal of Interventional Cardiology 2025;33(2):93-100
Objective To investigate whether successful percutaneous coronary intervention(PCI)could improve symptoms and quality of life(QOL)in left main disease and/or 3-vessel disease patients with diabetes.Methods Patients with left main disease and/or 3-vessel disease who underwent PCI in the First Affiliated Hospital of Air Force Medical University from April 2018 to May 2021 were consecutively enrolled and subdivided into 2 groups:diabetes and no diabetes.Detailed baseline characteristics,symptoms,including dyspnea and angina,assessed with the Rose dyspnea scale(RDS),Seattle angina questionnaire(SAQ),the European quality of life-5 dimensions(EQ-5D)and 12-item short-form health survey(SF-12)questionnaire respectively,procedural details,and 1 month and 1 year follow-up data were collected.Results Among 440 left main disease and/or 3-vessel disease patients,disease was present in 176(40.00%),who had more hypertension,peripheral artery disease,and LCX lesion(all P<0.05).The incidence of major adverse cardiovascular events(MACE)and all-cause mortality were similar between the two groups(both P>0.05)at 1 month follow-up,while all-cause mortality in diabetes patients was significantly higher than those without diabetes at 1 year follow-up(P=0.013).Low left ventricular ejection fraction was an independent risk factor for MACE and all-cause mortality at 1 month and 1 year follow-up after successful revascularization(all P<0.05).Most importantly,symptoms,including dyspnea and angina,and QOL were markedly improved regardless of diabetes both at 1 month and 1 year follow-up(all P<0.05).Diabetes patients showed improved dyspnea and QOL at similar degree to the non-diabetes patients(all P>0.05)and a more significantly relieved angina(P=0.013).Additionally,the number of chronic total occlusion(CTO)per patient was identified as an independent risk factor of dyspnea(OR 0.723,95%CI 0.525~0.997,P=0.048)and angina relief(OR 0.686,95%CI 0.473~0.995,P=0.047),and the contrast volume(OR 0.995,95%CI 0.992~0.999,P=0.008)as an independent risk factor of QOL improvement in diabetic patients.Conclusions Successful PCI is beneficial for relieving symptoms and improving quality of life in patients with diabetes who have left main disease and/or 3-vessel disease.
9.Clinicopathological and molecular genetic analysis of 10 cases of nephrogenic ade-noma/metaplasia in bladder
Wenwu LUO ; Mei LI ; Kun ZHONG ; Yu YIN
Chinese Journal of Clinical and Experimental Pathology 2025;41(5):584-590
Purpose To investigate the clinicopathological characteristics of nephrogenic adenoma/metaplasia(NA/M)of the bladder and analyze key points for diagnosis and differential diagnosis.Methods A retrospective a-nalysis was conducted on 10 cases of NA/M of the bladder,including clinical data,cystoscopic findings,microscopic morphology,and immunohistochemistry(IHC)results.Subsequently,a whole-exome sequencing(WES)was per-formed and a comprehensive literature review was supplemented.Results The cohort included 6 cases female and 4 cases male,aged 20-72 years(median:46.5 years).Three patients had a history of hydronephrosis(2 cases with nephrolithiasis and hydronephrosis,1 case with acute leukemia and bone marrow transplantation),2 cases had renal tuberculosis,1 case had erectile dysfunction,3 cases had a history of invasive high-grade urothelial carcinoma of the bladder,and 1 case had bladder endometriosis.All patients underwent cystoscopic biopsy,with pathological confirma-tion of NA/M.IHC showed that all 10 cases expressed PAX-8 and CK7 but were negative for GATA-3,p63/CK5/6,and PSA.The Ki67 proliferation index ranged from 1%to 10%.WES analysis of 7 cases revealed somatic single nu-cleotide variants(SNVs)involving multiple genes,with the highest mutation frequencies in FAM186A(86%),GOL-GA6L2(86%),and AQP7(86%).Conclusion NA/M is a benign but recurrent lesion,with rare malignant trans-formation after multiple recurrences.Comprehensive evaluation of histomorphological atypia and IHC results is recom-mended for accurate diagnosis and differential diagnosis to avoid misdiagnosis.Long-term follow-up is advised.WES findings suggest associations between NA/M and mutations in FAM186A,GOLGA6L2,and AQP7,providing potential directions for future research.
10.Measurement method based on EBT3 film technology for quality control detection of INTRABEAM PRS500 intraoperative radiotherapy equipment
Yi-kun LI ; Wei DING ; Xia-yu HANG ; Jun HU ; Xiang-dong SUN ; Ai-jun XU
Chinese Medical Equipment Journal 2025;46(6):47-53
Objective To propose an EBT3 film technology-based quality control measurement method for the INTRABEAM PRS500 intraoperative radiotherapy equipment to solve the problems of the traditional methods in cumbersome operation and setup error.Methods According to HJ 1198-2021 Requirements of radiation safety and protection for radiotherapy and GBZ 121-2020 Requirements for radiological protection in radiotherapy,the environmental radiation testing of the INTRABEAM PRS500 intraoperative radiotherapy equipment was carried out point by point by means of the radiation inspection instrument.The INTRABEAM PRS500 intraoperative radiotherapy equipment was characterized by a point X-ray source(XRS),and the XRS was detected in terms of the probe linearity,radiation dose,dynamic deviation,isotropy and dose rate.The EBT3 film technology was used to verify the symmetry and isotropy of the XRS planar dose of INTRABEAM PRS500 intraoperative radiotherapy equipment.Results The X-γ dose equivalent rate of each monitoring site of the INTRABEAM PRS500 intraoperative radiotherapy device was lower than the method detection limit(MDL).The results of SQA quality control showed that the INTRABEAM PRS500 intraoperative radiotherapy equipment XRS met the quality control requirements in terms of the probe linearity,radiation dose,dynamic deviation and etc,and the isotropy differences in the+X,-X,+Y,and-Y axis directions ranged from-1.40%to 1.79%,which were all within the allowable range of measurement tolerance(5.60%to 5.65%).The results of measuring the isotropy of the INTRABEAM PRS500 intraoperative radiotherapy equipment based on the EBT3 film technology showed that the dose distribution of the XRS in the directions of the+X,-X,+Y,and-Y axes at the same plane was well isotropic,and that the doses in the directions of the X and Y axes were symmetrically distributed,and that the maximum skewness value for the isotropy of the XRS in the XY plane was-1.581%,which met the requirements of AAPM TG61 report on the reference dosimetry of low-energy and medium-energy X-rays for radiotherapy and radiobiology of≤±5.3%.Conclusion The EBT3 film technology-based measurement method gains high simplicity and feasibility for the isotropy of the INTRABEAM PRS500 intraoperative radiotherapy equipment in the directions of the+X,-X,+Y,and-Y axes at the same planet,which realizes the dynamic monitoring of the dosimetric changes and facilitates the whole-process quality control management of the intraoperative radiotherapy equipment.[Chinese Medical Equipment Journal,2025,46(6):47-53]

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