In proton therapy,prompt gamma-ray imaging is considered as one of the most promising methods for assessing proton beam range.Prompt gamma-ray imaging detector evaluates the proton beam range based on the prompt gamma-ray distribution obtained by the prompt gamma-ray imaging system,which enables high-precision measurement of the proton beam range.Herein a proton beam range verification algorithm is designed for the newly developed prototype of the range verification detector(pixelated prompt gamma-ray imaging detector),which verifies the range estimation accuracy of the prototype for different phantoms and different energies of homogeneous media through Monte Carlo simulation.The results show that the accuracy of the proton beam range verification algorithm is within 0.5 mm of the safety margin error of the Bragg peak,and the measurement accuracy is significantly improved with the increase of the number of protons,indicating that the prototype algorithm is feasible for proton beam range verification.

Objective To investigate the diagnosis and treatment of multiple testicular Leydig cell tumors presenting with azoospermia.Methods Clinical data of a case of multiple testicular Leydig cell tumors presenting with azoospermia as well as re-lated article were reviewed.Results The patient visited the doctor due to"failure to conceive after 3 years of regular unprotect-ed sexual intercourse",and two consecutive semen analyses both indicated azoospermia.Testicular color Doppler ultrasound,en-hanced CT and pelvic MRI all suggested testicular space-occupying lesions.Preoperative evaluation suggested benign testicular tumors.Intraoperative frozen section pathology confirmed Leydig cell tumors.Microscopic testis-sparing tumor enucleation and microsurgical testicular sperm extraction(mTESE)were performed,with no sperm identified intraoperatively.The patient under-went successful tumor resection without complications.During the 12-month follow-up period,no tumor recurrence or metastasis was observed.Seminal volume increased compared to pre-operative levels,but azoospermia persisted.Conclusions Testicular Leydig cell tumor is a rare neoplasms originating from the gonadal stroma.Preoperative diagnosis is difficult.Radical orchiectomy is the primary treatment modality.However,testis-sparing tumor enucleation may be a safe and effective alternative for patients with bilateral testicular tumors.Tumor enucleation with testicular preservation is also a safe and effective choice for the patients with small-sized lesions or prepubertal status,whereas a long-term close follow-up is strictly implemented.

In proton therapy,prompt gamma-ray imaging is considered as one of the most promising methods for assessing proton beam range.Prompt gamma-ray imaging detector evaluates the proton beam range based on the prompt gamma-ray distribution obtained by the prompt gamma-ray imaging system,which enables high-precision measurement of the proton beam range.Herein a proton beam range verification algorithm is designed for the newly developed prototype of the range verification detector(pixelated prompt gamma-ray imaging detector),which verifies the range estimation accuracy of the prototype for different phantoms and different energies of homogeneous media through Monte Carlo simulation.The results show that the accuracy of the proton beam range verification algorithm is within 0.5 mm of the safety margin error of the Bragg peak,and the measurement accuracy is significantly improved with the increase of the number of protons,indicating that the prototype algorithm is feasible for proton beam range verification.

Objective To investigate the diagnosis and treatment of multiple testicular Leydig cell tumors presenting with azoospermia.Methods Clinical data of a case of multiple testicular Leydig cell tumors presenting with azoospermia as well as re-lated article were reviewed.Results The patient visited the doctor due to"failure to conceive after 3 years of regular unprotect-ed sexual intercourse",and two consecutive semen analyses both indicated azoospermia.Testicular color Doppler ultrasound,en-hanced CT and pelvic MRI all suggested testicular space-occupying lesions.Preoperative evaluation suggested benign testicular tumors.Intraoperative frozen section pathology confirmed Leydig cell tumors.Microscopic testis-sparing tumor enucleation and microsurgical testicular sperm extraction(mTESE)were performed,with no sperm identified intraoperatively.The patient under-went successful tumor resection without complications.During the 12-month follow-up period,no tumor recurrence or metastasis was observed.Seminal volume increased compared to pre-operative levels,but azoospermia persisted.Conclusions Testicular Leydig cell tumor is a rare neoplasms originating from the gonadal stroma.Preoperative diagnosis is difficult.Radical orchiectomy is the primary treatment modality.However,testis-sparing tumor enucleation may be a safe and effective alternative for patients with bilateral testicular tumors.Tumor enucleation with testicular preservation is also a safe and effective choice for the patients with small-sized lesions or prepubertal status,whereas a long-term close follow-up is strictly implemented.

【Objective】 To explore the application value of ¹⁸F-PSMA PET/CT on the detection of metastatic lesions of prostate cancer with serum total prostate specific antigen (tPSA) ≤20 ng/mL and the predictive variables affecting the imaging results, and to establish a predictive nomogram for the metastasis of prostate cancer. 【Methods】 The imaging, pathological, serum and clinical data of 175 pathologically confirmed prostate cancer patients who underwent ¹⁸F-PSMA PET/CT examination during Jan.2020 and Oct.2021 were retrospectively collected.The patients were divided into metastatic group and non-metastatic group according to PET/CT imaging results, and the positive detection rate of metastatic lesions was calculated.The independent influencing factors of ¹⁸F-PSMA PET/CT in the positive detection of metastatic lesions were determined with univariate and multivariate logistic regression analyses.The predictive nomogram was established. 【Results】 Of the 175 patients, metastatic lesions were detected in 78 cases and not detected in 97 cases, with a detection rate of 44.6% (78/175).There were statistically significant differences between the metastatic group and the non-metastatic group in urinary tract symptoms, androgen deprivation treatment (ADT) at the time of PET/CT examination and the risk level of Gleason score (GS) (P<0.05).Univariate logistic regression showed that urinary tract symptoms(OR=3.64, P<0.001), GS risk (OR=3.96, P<0.001) and concurrent ADT treatment (OR=3.71, P<0.001) were associated with the positive detection rate of metastatic lesions.Multivariate Logistic regression showed that urinary tract symptoms (OR=3.19, P=0.002), GS high-risk group (OR=2.95, P=0.005) and concurrent ADT treatment (OR=3.27, P=0.001) were independent predictors of positive detection rate. 【Conclusion】 The probability of metastasis in newly diagnosed prostate cancer patients with tPSA≤20 ng/mL is high.¹⁸F-PSMA PET/CT is of high value for the early detection of metastasis.Urinary tract symptoms, GS high-risk group and concurrent ADT treatment are independent predictors of metastatic lesions.The predictive nomogram can help assist clinical optimization of imaging examination path.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Bladder cancer is one of the most common urinary tumors.About 70％of the cases are non-muscle invasive bladder cancer(NMIBC)at the time of initial diagnosis while the recurrence rate is as high as 31％to 78％within 5 years.Furthermore,17％to 45％of the patients will develop muscle-invasive bladder cancer(MIBC)later.At present,the traditional chemical drugs and BCG intravesical therapy can no longer meet the clinical needs,and some systematic treatments have been applied to the patients with BCG failure.In recent years,a variety of new intravesical therapies,including immune gene therapy,photodynamic treatment and new combination of drugs and equipment,have been put into clinical applications.This article will review the novel research progress and provide a new direction for the treatment of NMIBC.

Objective To explore the safety and efficacy of neoadjuvant chemotherapy(NAC)combined with immunotherapy before radical cystectomy plus pelvic lymph nodes dissection(RC-PLND)for muscle-invasive bladder cancer(MIBC).Methods The clinical data of 101 patients with MIBC who underwent neoadjuvant therapy followed by RC-PLND in the Department of Urology,the First Affiliated Hospital of Xi'an Jiaotong University during Jan.2019 and Dec.2023 were retrospectively analyzed,including 71 patients(70.3％)who received NAC(NAC group)and 30(29.7％)who received NAC combined with immunotherapy(NAC combine immunotherapy group).The clinical and pathological data and adverse events during neoadjuvant therapy were compared.Logistic regression analysis was used to explore the independent predictors of pathological complete response(pCR)and pathological partial response(pPR).Results There were no significant differences in the baseline data between the two groups(P＞0.05).However,the proportion of multiple tumors in patients receiving NAC before surgery was significantly higher than that in the NAC combined immunotherapy group(69.0％vs.46.7％,P=0.034).Compared with NAC group,NAC combined with immunotherapy group had significantly improved rate of pathological downstaging and pPR(60.6％vs.83.3％,P=0.026;45.1％vs.70.0％,P=0.022).Furthermore,the rate of pCR in patients undergoing NAC combined immunotherapy was higher than those undergoing NAC,but the difference was not significant(53.3％vs.33.8％,P=0.067).Logistic regression analysis revealed that clinical T-stage and tumor diameter were independent predictors of pCR and pPR(P＜0.05).In addition,the most common adverse events during neoadjuvant therapy were anemia,decreased white blood cells,nausea,and vomiting,but most of them were grade 1-2 and could be relieved through symptomatic treatment.Conclusion NAC combined with immunotherapy is safe and effective,which can improve the rate of pathological downstaging,pPR and pCR,without increasing the incidence of adverse reactions.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in healthcare facilities in major regions of China in 2023.Methods Clinical isolates collected from 73 hospitals across China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2023 Clinical & Laboratory Standards Institute (CLSI) breakpoints.Results A total of 445199 clinical isolates were collected in 2023,of which 29.0％ were gram-positive and 71.0％ were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species (excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi) (MRSA,MRSE and MRCNS) was 29.6％,81.9％ and 78.5％,respectively.Methicillin-resistant strains showed significantly higher resistance rates to most antimicrobial agents than methicillin-susceptible strains (MSSA,MSSE and MSCNS).Overall,92.9％ of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 91.4％ of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis had significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 93.1％ in the isolates from children and and 95.9％ in the isolates from adults.The resistance rate to carbapenems was lower than 15.0％ for most Enterobacterales species except for Klebsiella,22.5％ and 23.6％ of which were resistant to imipenem and meropenem,respectively .Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.6％ to 10.0％.The resistance rate to imipenem and meropenem was 21.9％ and 17.4％ for Pseudomonas aeruginosa,respectively,and 67.5％ and 68.1％ for Acinetobacter baumannii,respectively.Conclusions Increasing resistance to the commonly used antimicrobial agents is still observed in clinical bacterial isolates.However,the prevalence of important crabapenem-resistant organisms such as crabapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a slightly decreasing trend.This finding suggests that strengthening bacterial resistance surveillance and multidisciplinary linkage are important for preventing the occurrence and development of bacterial resistance.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in healthcare facilities in major regions of China in 2023.Methods Clinical isolates collected from 73 hospitals across China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2023 Clinical & Laboratory Standards Institute (CLSI) breakpoints.Results A total of 445199 clinical isolates were collected in 2023,of which 29.0％ were gram-positive and 71.0％ were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species (excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi) (MRSA,MRSE and MRCNS) was 29.6％,81.9％ and 78.5％,respectively.Methicillin-resistant strains showed significantly higher resistance rates to most antimicrobial agents than methicillin-susceptible strains (MSSA,MSSE and MSCNS).Overall,92.9％ of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 91.4％ of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis had significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 93.1％ in the isolates from children and and 95.9％ in the isolates from adults.The resistance rate to carbapenems was lower than 15.0％ for most Enterobacterales species except for Klebsiella,22.5％ and 23.6％ of which were resistant to imipenem and meropenem,respectively .Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.6％ to 10.0％.The resistance rate to imipenem and meropenem was 21.9％ and 17.4％ for Pseudomonas aeruginosa,respectively,and 67.5％ and 68.1％ for Acinetobacter baumannii,respectively.Conclusions Increasing resistance to the commonly used antimicrobial agents is still observed in clinical bacterial isolates.However,the prevalence of important crabapenem-resistant organisms such as crabapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a slightly decreasing trend.This finding suggests that strengthening bacterial resistance surveillance and multidisciplinary linkage are important for preventing the occurrence and development of bacterial resistance.