1.Biomechanical comparison of posterior short-segment fixation with or without intermediate screws for thoracolumbar burst fractures under normal and osteoporotic conditions: a finite element analysis
Cheng XU ; XiangMing ZHANG ; Hong Jian CAO ; Chao SHEN ; Feng GE ; Xuedong BAI ; Chao ZHANG
Asian Spine Journal 2026;20(2):223-231
Methods:
Six finite element models of T12 burst fractures were developed to simulate short-segment stabilization under normal or osteoporotic bone conditions, with/without augmentation screws at the fractured vertebra. Spinal stiffness, implant stresses, and axial displacement/micromotion of the bony defect were measured and compared under mechanical loading.
Results:
Osteoporotic models exhibited a greater range of motion (ROM) than normal bone. All six-screw constructs reduced ROM across all motions compared with traditional four-screw models. Osteoporotic fracture models gained greater benefit from intermediate screw augmentation at the fracture vertebra, which also lowered axial displacement/micromotion. In six-screw models, rod stress increased while pedicle screw stress decreased. Intermediate screws at fractured vertebrae produced similar changes in stress distribution across all fixation models, regardless of bone quality.
Conclusions
Our findings may facilitate implant selection for osteoporotic burst fractures, supporting the use of more rigid fixation sixscrew constructs to reduce the risk of mechanical failure and postoperative re-collapse.
2.Antibody levels of diphtheria and tetanus in healthy population in Pudong New Area, Shanghai, 2018-2024
Yu BAI ; Dandan YANG ; Wanran CHENG ; Rui ZHANG ; Pengfei DENG ; Caoyi XUE ; Laibao YANG ; Yi FEI
Journal of Public Health and Preventive Medicine 2026;37(3):52-55
Objective To understand the antibody levels of diphtheria and tetanus among healthy population in Shanghai Pudong New Area, and to provide a scientific basis for improving the vaccine immunization strategy. Methods Random sampling was used to select healthy people of all ages in 16 communities in Shanghai Pudong New Area from 2018 to 2024, and serum samples were collected and tested for serum anti-diphtheria and tetanus toxin IgG antibodies by enzyme-linked immunosorbent assay (ELISA) method to analyze the antibody positivity rate (≥0.1 IU/ml) and the geometric mean concentration (GMC) of antibodies. Results A total of 3 312 serum samples were included, with a male-to-female ratio of 0.76:1, and 53.77% were local residents. The seropositivity rates and geometric mean concentrations (GMC) of both diphtheria and tetanus antibodies generally declined with increasing age, but exhibited a transient rebound in the 7y-. A total of 1 175 individuals (35.48%) were seropositive for diphtheria, with a GMC of 0.054 IU/mL. For tetanus, 988 individuals (29.83%) were seropositive, with a GMC of 0.033 IU/mL. Significant differences in seropositivity rates (χ2diphtheria=950.005,χ2tetanus=1 324.393) and GMC (Hdiphtheria=1027.160,Htetanus=1 142.007) were observed among different age groups (P<0.001). Significant differences in seropositivity rates (χ2diphtheria=950.005,χ2tetanus=1324.393) and GMC (Hdiphtheria=1027.160,Htetanus=1142.007) were also found across different years (P<0.001). Conclusion The prevalence of diphtheria and tetanus antibodies in the healthy population of Pudong New Area is relatively low, particularly among adults over 20 years of age with inadequate immunization. This underscores the need to reinforce the National Immunization Program (NIP) vaccine specifications for children under 6 years of age and implement an immunization strategy for adolescents or adults against diphtheria and tetanus.
3.Establishment and preliminary evaluation of a fluorescent recombinase-aided amplification assay for detection of Strongyloides stercoralis
Xiaodan CHEN ; Wanqiong CHENG ; Xiaoyin FU ; Jiayin LÜ ; Jiayue SUN ; Qiuhua BAI ; Xue HAN ; Yunliang SHI ; Dengyu LIU
Chinese Journal of Schistosomiasis Control 2026;38(2):160-168
Objective To establish a fluorescent recombinase-aided amplification (RAA) assay for detection of Strongyloides stercoralis nucleic acid and to preliminarily evaluate its performance. Methods Six sets of specific primers targeting S. stercoralis 18S ribosomal RNA (18S rRNA) gene and one fluorescent probe were designed and synthesized. The optimal primer-probe set was determined through systematic screening and optimization to establish the fluorescent RAA assay. The assay was evaluated using S. stercoralis genomic DNA at concentrations of 100, 10, and 1 pg/μL, and 100, 10, and 1 fg/μL, as well as recombinant pUC57 plasmids containing the target gene fragments at 1 × 105, 1 × 104, 1 × 103, 1 × 102, 1 × 101, 1 × 100 copies/reaction, to determine the analytical sensitivity. Genomic DNA from Ascaris lumbricoides, Ancylostoma duodenale, Enterobius vermicularis, Angiostrongylus cantonensis, Trichinella spiralis, Clonorchis sinensis, Schistosoma japonicum, and Taenia saginata was used to assess assay specificity. A total of 25 stool samples from patients suspected of S. stercoralis infection were tested by the modified Baermann funnel technique, PCR, and the established fluorescent RAA assay. The sensitivity, specificity, concordance rate and their 95% confidence intervals (CI) of these three techniques were estimated, and agreement between methods was evaluated using the Kappa coefficient. Results Exo-4 was identified as the optimal primer set screened from the six primer sets, and the best amplification performance was achieved when the final concentrations of the forward and reverse primers were 0.44 μmol/L and a probe concentration was 0.20 μmol/L. The limit of detection of the fluorescent RAA assay was 100 fg/μL for genomic DNA of S. stercoralis and 1 × 100 copies/reaction for recombinant plasmids. Specific fluorescence signals were detected within 5 min, with no cross-reactivity observed with A. lumbricoides, A. duodenale, E. vermicularis, A. cantonensis, T. spiralis, C. sinensis, S. japonicum, or T. saginata. Among the 25 clinical stool samples from patients suspected of S. stercoralis infections, the modified Baermann funnel technique and fluorescent RAA assay detected 19 positives and 6 negatives, whereas PCR detected 18 positives and 7 negatives. The fluorescent RAA assay showed a sensitivity of 100.00% [95% CI: (82.35%, 100.00%)], specificity of 100.00% [95% CI: (54.07%, 100.00%)], concordance rate of 100.00% [95% CI: (86.28%, 100.00%)], and a Kappa coefficient of 1.00 [95% CI: (1.00, 1.00)] (P < 0.001) relative to the modified Baermann funnel technique, and a sensitivity of 100.00% [95% CI: (81.47%, 100.00%)], specificity of 85.71% [95% CI: (42.13%, 99.64%)], concordance rate of 96.00% [95% CI: (79.65%, 99.90%)], and a Kappa coefficient of 0.90 [95% CI: (0.70, 1.00)] (P < 0.001). Positive amplification products emitted green fluorescence under a portable blue-light device, enabling visual interpretation of results. Conclusions The fluorescent RAA assay established in this study is rapid, highly sensitive, and highly specific. It enables detection of S. stercoralis nucleic acid under isothermal conditions and allows visual interpretation of results, providing a novel tool for rapid clinical diagnosis and field screening of S. stercoralis infections.
4.Research on safety risk signals of five drugs for Gaucher disease
Cheng YI ; Qiwei HAN ; Jing XU ; Nianfeng GUO ; Mengru BAI
China Pharmacy 2026;37(12):1607-1613
OBJECTIVE To evaluate the characteristics of adverse drug event (ADE) associated with five therapeutic agents for Gaucher disease(imiglucerase, velaglucerase alfa, taliglucerase alfa, eliglustat,and miglustat). METHODS ADE reports related to the above five drugs were retrieved from the FDA Adverse Event Reporting System (FAERS) database from January 2004 to September 2025. The reporting odds ratio (ROR) and proportional reporting ratio (PRR) methods were applied for data mining. system organ class (SOC) and preferred term (PT) from the Medical Dictionary for Regulatory Activities (MedDRA, version 26.0) drug ADE terminology were used for classification and statistical analysis of ADE. RESULTS A total of 4 329, 1 740, 500, 1 329 and 998 ADE reports were retrieved for the aforementioned five drugs, respectively, generating 4 612, 2 605, 776, 1 157 and 2 185 ADE signals. These signals involved 26 SOC, affecting 25, 26, 16, 19, and 19 SOC, respectively. The predominant SOCs were various injuries, poisoning and procedural complications, as well as infections and infestations. The top one PTs of each drug were as follows: bone infarction, zinc deficiency, failure to perform drug monitoring steps, ichthyosis, abnormal nerve conduction examination. New suspected PTs included weight gain and spontaneous abortion for imiglucerase and velaglucerase alfa, weight gain for taliglucerase alfa and eliglustat, and neuropsychiatric manifestations such as dementia and apathy for miglustat. In terms of severe ADEs, other serious medical events were predominant for imiglucerase and taliglucerase alfa; prolonged hospital stays were the main severe ADE for velaglucerase alfa and eliglustat; and death was the leading severe ADE for miglustat. CONCLUSIONS In clinical medication, apart from common ADE,for imiglucerase, clinicians should be alert to bone infarction, weight gain and spontaneous abortion, and strengthen monitoring related to bones, metabolism and pregnancy. For velaglucerase alfa, attention should be paid to zinc deficiency, bone infarction, weight gain and spontaneous abortion, with focused monitoring of nutritional status and pregnancy risks. For taliglucerase alfa, failure to perform drug monitoring steps and weight gain require vigilance, and medication procedures should be standardized along with regular weight monitoring. For eliglustat, clinicians need to watch out for ichthyosis and weight gain and pay close attention to skin conditions. For miglustat, bone infarction, abnormal nerve conduction examination and dementia should be closely monitored, with enhanced surveillance on nervous system function, infections and prognosis of critically ill patients,to ensure patient medication safety.
5.Trajectories of body mass index for age z-score and its influencing factors among children with congenital hypothyroidism
CHENG Lingling ; YAN Yaqiong ; BAI Zenghua ; ZHANG Xiaogang ; HAO Liting ; YANG Huiying
Journal of Preventive Medicine 2025;37(8):858-863
Objective:
To analyze the trajectories of body mass index for age z-score (BAZ) and its influencing factors among children with congenital hypothyroidism (CH) based on latent class growth modeling (LCGM), so as to provide the evidence for improving treatment measures and optimizing growth management among children with CH. Methods Children with CH aged 0 to 3 years from the Newborn Disease Screening Center of Shanxi Children's Hospital (Shanxi Maternal and Child Health Hospital) between 2017 and 2022 were selected as the research subjects. Basic information, height and weight data from 3 to 36 months of age, age at treatment initiation, thyroid-stimulating hormone (TSH) levels at diagnosis, and family information were retrospectively collected. BAZ for children with CH at each month of age was calculated based on the WHO Child Growth Standards. The trajectories of BAZ were analyzed using LCGM, and factors affecting the trajectories of BAZ among children with CH were analyzed using a multinomial logistic regression model.
Methods:
Children with CH aged 0 to 3 years from the Newborn Disease Screening Center of Shanxi Children's Hospital (Shanxi Maternal and Child Health Hospital) between 2017 and 2022 were selected as the research subjects. Basic information, height and weight data from 3 to 36 months of age, age at treatment initiation, thyroid-stimulating hormone (TSH) levels at diagnosis, and family information were retrospectively collected. BAZ for children with CH at each month of age was calculated based on the WHO Child Growth Standards. The trajectories of BAZ were analyzed using LCGM, and factors affecting the trajectories of BAZ among children with CH were analyzed using a multinomial logistic regression model.
Results:
A total of 299 children with CH were included. There were 140 boys (46.82%) and 159 girls (53.18%). The median of BAZ was 0.50 (interquartile range, 1.68). The LCGM analysis categorized the subjects into three groups: the persistent high-growth pattern group with 24 cases (8.03%), the slow-growth pattern group with 39 cases (13.04%), and the appropriate-growth pattern group with 236 cases (78.93%). Multinomial logistic regression analysis showed that compared to the children with CH in the appropriate-growth pattern group, those who started treatment at the age of 30 to 60 days (OR=0.109, 95%CI: 0.016-0.732; OR=0.166, 95%CI: 0.032-0.852) had a lower risk of persistent high-growth and slow-growth patterns; CH children with TSH levels of 50 to 150 mIU/L at diagnosis (OR=3.554, 95%CI: 1.201-10.514) and those whose paternal had a senior high school/technical secondary school education (OR=2.975, 95%CI: 1.003-8.823) exhibited a higher risk of the persistent high-growth pattern. Conversely, CH children whose paternal reproductive age was 30 to 35 years (OR=0.166, 95%CI: 0.034-0.806) had a lower risk of the persistent high-growth pattern.
Conclusions
The BAZ trajectory of children with CH aged 0 to 3 years exhibited three patterns: persistent high-growth, slow-growth, and appropriate-growth. The persistent high-growth and slow-growth patterns were associated with treatment timing, TSH levels at diagnosis, paternal reproductive age, and paternal education level. It is recommended to strengthen early treatment interventions and provide family follow-up guidance.
6.Effects of Transcutaneous Electrical Acupoint Stimulation on Postoperative Analgesic Consumption and Adverse Reactions in Total Knee Arthroplasty
Hongkai PENG ; Ting CHENG ; Pengcheng SHAN ; Hongjie WANG ; Yueling XU ; Yifei WEI ; Guannan WEN ; Tianyu BAI
Chinese Journal of Information on Traditional Chinese Medicine 2025;32(2):169-174
Objective To investigate the efficacy and safety of transcutaneous electrical acupoint stimulation(TEAS)in reducing the consumption of analgesics after total knee arthroplasty(TKA).Methods Totally 124 patients undergoing unilateral TKA were included and divided into an intervention group and a control group according to random number table method,with 62 cases in each group.Both groups received routine postoperative analgesic protocols,with the intervention group additionally receiving TEAS treatment,30 min per time,twice a day.The additional doses of intravenous patient-controlled analgesia pumps and opioid analgesic consumption in two groups of patients after surgery were analyzed,as well as the adverse events and laboratory test results(WBC,PLT,SCr,BUN,ALT and AST)in both groups.Results The number of additional doses in the intervention group with the patient-controlled analgesia pump and the consumption of opioid analgesic were both lower than those in the control group(P<0.05);the incidence of postoperative nausea symptoms in the intervention group was lower than that in the control group,while other adverse reactions showed no significant difference(P>0.05).There was no significant difference in laboratory test results(WBC,PLT,SCr,BUN,ALT and AST)between the two groups on the day before surgery and on the 1st and 7th days after surgery(P>0.05).Conclusion TEAS can reduce the consumption of analgesics after TKA,decrease some adverse reactions associated with the use of analgesics,and has good safety.
7.Multi-center clinical study on the efficacy and safety of combined lienal polypeptide injection therapy in children with Mycoplasma pneumoniae pneumonia
Qi CHENG ; Yunxiao SHANG ; Han ZHANG ; Jiujun LI ; Ning CHEN ; Lishen SHAN ; Nan YANG ; Lihua NING ; Xuemei BAI ; Jianhua LIU ; Yuling HAN ; Jichun WANG ; Jing LI ; Yong FENG ; Liyun LIU ; Li CHEN ; Si LIU ; Qinzhen ZHANG ; Jia ZHENG ; Fengchao LI ; Sukun LU ; Yun ZHANG ; Xiaoyi CHAI
International Journal of Pediatrics 2025;52(3):204-210
Objective:To observe the efficacy and safety of combined lienal polypeptide injection therapy in the treatment of Mycoplasma pneumoniae pneumonia(MPP)in children aged 3 to 14 years old in multiple clinical centers.Methods:A randomized,controlled,multi-center clinical study design was adopted.A total of 240 hospitalized children aged 3 to 14 years old with MPP from 7 hospitals from September 1,2023 to January 31,2024 were included.According to the severity of pneumonia,they were divided into the mild MPP group with 80 cases and the severe MPP/refractory MPP(SMPP/RMPP)group with 160 cases,and then randomly divided into the control group and the experimental group at a ratio of 1 ∶1,using the random number table method.After screening,subjects entered a treatment period of 5 to 7 days.The control group was treated with azithromycin,while the experimental group was treated with azithromycin plus lienal polypeptide injection .The recovery of lung CT,length of hospital stay,duration of fever,cough score,whether mild cases developed into severe or refractory cases,duration of hormone use,use of intravenous immunoglobulin(IVIG),bronchoscopy treatment,and immune function were observed between the two groups to evaluate the efficacy of lienal polypeptide injection.Adverse events after medication,vital signs,blood routine,urine routine,liver function,myocardial enzymes,renal function,and electrocardiogram were observed to evaluate the safety. Results:A total of 231 subjects have completed the trial in the 7 hospitals,including 118 cases in the experimental group and 113 cases in the control group.Main observation index:the rate of lung CT aggravation in the experimental group was lower than that in the control group(2.6% vs 15.3%, P<0.01),and the difference was statistically significant.Secondary indexes:there were no statistically significant differences in the length of hospital stay,duration of fever,cough score,duration of hormone use,whether IVIG treatment was used,the number of bronchoscopy treatment cases,and immunoglobulin between the two groups(all P>0.05).However,the rate of cases of plastic bronchitis(PB)found under bronchoscopy in the experimental group was lower than that in the control group(0 vs 18.8%, P=0.03),and the difference was statistically significant.Among the mild MPP(72 cases),there were no statistically significant differences in the length of hospital stay,duration of fever,cough score,duration of hormone use,whether IVIG treatment was used,the number of bronchoscopy treatment cases,and the improvement rate of lung CT between the two groups(all P>0.05).However,compared with the control group,the rate of cases developing into SMPP/RMPP in the experimental group was less(24.3% vs 48.6%, P=0.03),and the difference in IgG before and after treatment was small[0.53(-0.04,1.18)g/L vs 1.33(0.48,2.25)g/L, P=0.01].Among the SMPP/RMPP cases(159 cases),the rate of cases of PB found under bronchoscopy in the experimental group was less than that in the control group(0 vs 20%, P=0.04),and the rate of cases with aggravated lung CT in the experimental group was less than that in the control group(1.3% vs 19.5%, P<0.01),and the improvement rate of lung CT in the experimental group was higher than that in the control group(88.8% vs 75.3%, P=0.03),with statistically significant differences.There were no statistically significant differences in the length of hospital stay,duration of fever,cough score,duration of hormone use,whether IVIG treatment was used,the number of bronchoscopy treatment cases,and immunoglobulin between the two groups(all P>0.05).Two cases in the experimental group developed rashes,which improved after the drug was discontinued.There were no serious adverse reactions such as abnormal vital signs like dyspnea and cyanosis due to the use of lienal polypeptide injection.There were no obvious changes in blood routine,liver function,myocardial enzymes,renal function,electrocardiogram,and urine routine values before and after medication compared with the baseline. Conclusion:The combined use of lienal polypeptide injection in the treatment of MPP in children can reduce the probability of the transformation from mild cases to SMPP/RMPP,reduce the rate of aggravation of the image findings,promote the absorption of lung inflammation,reduce the rate of PB found under bronchoscopy,and has good safety.
8.Analysis of dosimetric characteristics of proton radiotherapy in 1 case of whole central nervous system tumor
Shizhang WU ; Man HU ; Tianyuan DAI ; Chengqiang LI ; Cheng TAO ; Jinghao DUAN ; Jinhu CHEN ; Tong BAI ; Tian KONG ; Jian ZHU
Journal of International Oncology 2025;52(7):434-440
Objective:To explore the dosimetric characteristics of intensity modulated proton therapy (IMPT), intensity modulated radiation therapy (IMRT) and tomotherapy (TOMO) techniques applied in the irradiation of pediatric whole central nervous system tumors.Methods:Taking the target area of a 14-year-old pediatric patient clinically diagnosed with atypical teratoid/rhabdomyoid tumor, meningeal metastasis by Shandong Cancer Hospital and Institute, and undergoing craniospinal irradiation (CSI) as an example, IMPT, IMRT and TOMO plans were designed respectively based on the clinical prescription of the target area and the limit requirements of organs at risk (OARs). The conformal index (CI), homogeneity index (HI) and gradient index (GI) of each planning target volume, as well as the dose volume index of normal tissues, were evaluated to compare the dosimetric characteristics of the three types of plans.Results:The CI (0.71), HI (0.05) and GI (3.13) of the IMPT plan were comparable to those of IMRT plan (0.80, 0.08, 3.14). The HI (0.03) and GI (2.54) of the TOMO plan were excellent, which were all within the clinically acceptable range. The irradiation dose to parallel organs in the IMPT plan was lower than that in the IMRT and TOMO plan. In the IMPT plan, V 5 of lungs was 2.9%, IMRT plan was 37.6%, and TOMO plan was 43.5%. The D mean of liver in the IMPT plan was 0.01 Gy (RBE), IMRT plan was 6.12 Gy, and TOMO plan was 6.39 Gy. In the IMPT plan, none of the bladder, rectum, and femoral head received the dose, while there was low-dose radiation in both IMRT and TOMO plan. For serial organs adjacent to and within the target area, the D max of spinal cord and brainstem in IMPT plan was 39.89 and 39.88 Gy (RBE), respectively; in IMRT plan, they were 39.43 and 38.59 Gy, respectively; and in TOMO plan, they were 38.41 and 37.69 Gy, respectively. The low-dose area in the IMPT plan was significantly better than the photon radiotherapy plans. Among them, the absolute volume IMPT plan occupied by 10% of the prescribed dose area in the patient's body was reduced by 70.10% compared with IMRT plan and 76.96% compared with TOMO plan; the 30% prescribed dose volume IMPT plan was reduced by 53.49% compared with IMRT plan and 62.51% compared with TOMO plan; the 50% prescribed dose volume IMPT plan was reduced by 39.06% compared with IMRT plan and 42.23% compared with TOMO plan. Conclusions:The IMPT plan demonstrated significantly reduced low-dose exposure and lower doses to parallel OARs compared to both IMRT and TOMO plans in pediatric CSI. The CI, HI and GI of the three plans can all meet the clinical requirements. However, for serial organs adjacent to and within the target area, the D max of the IMPT plan may be higher than that of IMRT and TOMO plans.
9.Analysis of dosimetric characteristics of proton radiotherapy in 4 cases of breast cancer
Chengqiang LI ; Yungang WANG ; Yishan YU ; Shizhang WU ; Cheng TAO ; Xingmin MA ; Tianyuan DAI ; Jinghao DUAN ; Jinhu CHEN ; Tong BAI ; Jian ZHU
Journal of International Oncology 2025;52(7):448-454
Objective:To explore the dosimetric characteristics of proton and photon radiotherapy in the treatment of breast cancer.Methods:Four female breast cancer patients who needed radiotherapy at Shandong Cancer Hospital and Institute from January 2024 to May 2024 were selected as the research subjects. The target area ranges of 4 patients were left-sided breast cancer with lymph node involvement, left-sided breast cancer with lymph node involvement and internal mammary node, right-sided breast cancer with lymph node involvement and internal mammary node and synchronous bilateral breast cancer. Intensity modulated proton therapy (IMPT) and intensity modulated radiation therapy (IMRT) plans were designed respectively based on the prescribed dose in the target area and the limits of organs at risk (tomotherapy plan for bilateral breasts). The conformity index (CI), homogeneity index (HI), gradient index (GI) and organs at risk doses were evaluated. The dosimetric characteristics of IMPT and photon radiotherapy were compared.Results:Both IMPT and photon radiotherapy plans of the 4 breast cancer cases met the clinical dose requirements. The HI value of IMPT plans (0.10-0.14) was comparable to that of photon radiotherapy plans (0.10-0.12), and the average CI of the photon radiotherapy plans was 0.10 higher than that of the IMPT plans, and the average GI was 0.55 lower than that of the IMPT plans. The D mean of ipsilateral lung and heart of IMPT was lower, especially in the low-dose area (V 0-3), which was significantly lower than the photon radiotherapy plans, D mean of ipsilateral lung was reduced by 12.2%, 6.1%, 16.1% and 34.8%, respectively, D mean of heart was reduced by 47.2%, 57.0%, 72.4% and 83.0%, respectively. The ipsilateral lung V 20 of IMPT was not lower than photon radiotherapy plans (unilateral breast: IMPT was 30.0%-34.0%, IMRT was 29.0%-35.9%) . Conclusions:IMPT significantly reduces the D mean to the ipsilateral lung and heart while ensuring dose coverage of the target in breast cancer, preventing more volume of surrounding normal tissues from being irradiated. However, IMPT does not show much more advantage than photon radiotherapy plans in the ipsilateral lung V 20.
10.Analysis of dosimetric characteristics of proton radiotherapy in 3 cases of abdominal and pelvic tumors
Jinghao DUAN ; Jinbo YUE ; Cheng TAO ; Shizhang WU ; Chengqiang LI ; Tianyuan DAI ; Jinhu CHEN ; Tong BAI ; Jian ZHU
Journal of International Oncology 2025;52(7):455-461
Objective:To explore the dosimetric characteristics of intensity modulated proton therapy (IMPT) and intensity modulated radiation therapy (IMRT) for typical abdominal and pelvic tumors.Methods:Three patients with abdominal and pelvic tumors (one case each of liver cancer, cervical cancer, and prostate cancer) admitted to Shandong Cancer Hospital and Institute from January to June 2024 were selected as the research subjects. IMPT and IMRT plans were designed for each case based on clinical target volume (CTV) and organs at risk (OARs) constraints. Dosimetric parameters, including conformity index (CI), homogeneity index (HI), and gradient index (GI) for target coverage, as well as OARs dose metrics, were evaluated. The volume of additional dose deposition in the body was compared by assessing regions receiving 10%, 30%, and 50% of the prescription dose.Results:For all three cases, IMRT plan demonstrated higher CI values (0.82, 0.81, and 0.86) compared to IMPT plan (0.61, 0.62, and 0.43). IMPT plan yielded lower HI values (0.053, 0.075, and 0.020) than IMRT plan (0.060, 0.120, and 0.080) and lower GI values (3.45, 2.63, and 3.80 vs. 7.28, 4.76, and 4.66 for IMRT plan). In liver cancer, IMPT plan reduced the D mean of normal liver tissues and right kidney by 37.8% and 78.5%, respectively, and decreased the D max of spinal cord by 13.2%. For cervical cancer, IMPT plan reduced the V 30 of the small bowel by 22.0%, D mean of the bladder, rectum and bone marrow by 15.7%, 14.3% and 12.6%, and spinal cord D max by 4.8%. In prostate cancer, IMPT plan lowered bladder and rectal D mean by 14.9% and 36.5%, respectively, but resulted in an increase of 35.3% and 6.1% in the D mean and V 40 of the left femoral head, respectively, and an increase of 23.6% and 10.8% in the D mean and V 40 of the right femoral head, respectively. IMPT plan reduced the volumes receiving 10%, 30%, and 50% of the prescription dose by 48.9%-64.8%, 22.0%-47.0%, and 22.0%-57.7%, respectively, compared to IMRT plan. Conclusions:Comparison between IMPT and IMRT plans for abdominopelvic tumors: IMPT plan offers advantages in reducing doses to normal organs such as the liver, kidneys, spinal cord, small intestine, rectum, and bladder. However, its advantage is less pronounced regarding the dose to the femoral heads. IMPT plan notably minimizes additional dose deposition within the body.


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