Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

Pancreatic cancer is highly aggressive and often diagnosed at an advanced stage,leaving most patients ineligible for radical resection.This study retrospectively analyzed four patients with locally advanced or advanced pancreatic cancer to evaluate the clinical efficacy and safety of high-intensity focused ultrasound(HIFU)ablation combined with chemotherapy as a neoadjuvant and conversion therapy.All cases were reviewed and individualized treatment plans were formulated through a multidisciplinary team evaluation.All patients received HIFU plus gemcitabine and nab-paclitaxel chemotherapy,with assessments of tumor volume,vascular involvement,surgical conversion,symptom relief,and adverse events.Three patients achieved marked tumor shrinkage and reduction of vascular invasion,enabling successful R0 resection without recurrence during follow-up.The remaining patient achieved disease stability,significant pain relief,and maintained good quality of life under repeated HIFU therapy.All treatments were well tolerated,and no severe adverse reactions occurred.The combination of HIFU and chemotherapy demonstrated synergistic local and systemic effects,effectively achieving tumor downstaging,improving resectability,and alleviating symptoms.As a safe,noninvasive,and repeatable therapeutic approach,this strategy offers a promising option for patients with advanced pancreatic cancer.Further large-scale prospective studies are warranted to validate its long-term efficacy and elucidate underlying mechanisms.

Background and Aims:Infected necrotizing pancreatitis(INP),particularly with diffuse distribution,is a life-threatening condition.The optimal initial intervention-minimally invasive step-up therapy vs.direct open necrosectomy-remains controversial.Moreover,the impact of necrosis morphology("wet"or"dry")and the presence of severe acute pancreatitis(SAP)on treatment selection has not been fully clarified.This study aimed to compare the efficacy and safety of these two approaches in diffuse INP and to evaluate the guiding value of CT-based necrosis type and SAP status in clinical decision-making.Methods:A retrospective analysis was conducted on 458 patients with diffuse INP admitted to the Third Xiangya Hospital of Central South University from January 2012 to March 2023.Patients were divided into a minimally invasive step-up group(n=256)and a direct open surgery group(n=202).SAP was defined according to the determinant-based classification,and necrosis was categorized as"wet"or"dry"based on CT features.The primary endpoint was a composite of death or major complications,while secondary endpoints included mortality,length of hospital stay,and incision-related complications,were compared between the two groups,with subgroup analyses performed accordingly.Results:Overall,the open surgery group had higher rates of the primary endpoint(62.4%vs.48.1%,P=0.003)and mortality(27.2%vs.16.8%,P=0.008)compared with the step-up group.Among SAP patients,the step-up approach resulted in a significantly lower primary endpoint rate(66.7%vs.97.7%,P=0.003).In non-SAP patients,the primary endpoint rates were similar,but open surgery was associated with a shorter hospital stay[(36.5±10.4)d vs.(45.6±18.6)d,P<0.001]and higher incidences of wound infection and incisional hernia(both P<0.001).Multivariate analysis identified infection onset time,effusion characteristics,gas bubbles,and necrosis location as independent predictors of prolonged hospitalization in the step-up group(all P<0.05).Patients with"wet"necrosis benefited more from the step-up approach,whereas those with"dry"necrosis experienced shorter hospitalization following open surgery.Conclusion:For diffusely distributed INP,treatment strategies should be individualized based on SAP status and necrosis liquefaction/imaging characteristics.The step-up minimally invasive approach is preferred for SAP patients and those with"wet"necrosis on CT,while direct open necrosectomy may be advantageous for"dry"necrosis(particularly with limited liquefaction)by shortening hospital stay and reducing certain major outcomes,though at the cost of increased incision infection and incision herina.CT imaging features and SAP classification can serve as valuable tools for risk stratification and guiding individualized timing and modality of intervention.

This study was aimed at tracing the molecular typing and drug resistance characteristics of a suspected food poi-soning event caused by Clostridium perfringens in a district of Wuhan City.The FilmArray detection system and multiple fluo-rescence quantitative PCR methods were used to rapidly screen for pathogens in samples from the poisoning event.According to the initial screening results,bacteria were isolated,cultured,and identified by mass spectrometry.Fluorescence PCR was used to detect six virulence genes of the isolated Clostridium perfringens strains.On the basis of whole genome sequencing results,we conducted virulence genes,resistance genes,and whole genome single nucleotide polymorphism genetic evolution(wgSNPs)analyses.Antibiotic sensitivity testing was conducted with the agar dilution method.A total of ten strains of Clos-tridium perfringens were isolated,including eight strains from seven anal swab samples,one strain from fecal samples,and one strain from food samples.Food with suspected contamination had a Clostridium perfringens count of 7.8×106 CFU/g.The PLC(a)toxin gene was detected in all ten gas producing capsule isolation strains,but no other 5 tox-in genes such as CPE were detected,thus confirming that all were type A bacteria producing capsule Clostridium.All strains were 100％resistant to clindamycin and almost completely sensitive to antibiotics such as vancomycin,cefoxitin,and meropenem.Ten strains of Clos-tridium perfringens carried resistance genes such as tetB(P),tetA(P),and mprF,followed by ermQ(70％),ant(6)-Ⅰb(10％),and LnuP(10％).Genetic evolution analysis of wgSNPs indicated that the four outbreak strains clustered together and belonged to an independent subbranch with the suspected food sourcestrains,thus indicating close genetic relationships.In con-clusion,this food poisoning incident might have been be caused by hand torn chickens contaminated with Clostridium perfrin-gens,and the molecular types of the strains revealed high genetic diversity.No multiple drug resistance was observed,but all strains were resistant to clindamycin,an aspect requiring further clinical attention.

Objective To determine the pathogenicity of a novel mutation(c.109_111del)in DKC1 gene of an adult patient,and to analyze the clinical phenotype,immunophenotype and telomere length,so as to provide clues for early clinical identification and diagnosis.Methods The clinical data and peripheral blood samples of the patient were collected for genetic testing and family analysis.The lymphocyte subsets of the patient were detected by Flow cytometry,and the telomere length of the patient and healthy controls were detected by Flow-FISH.Results The main clinical manifestations of the patient were mucocutaneous triad,bone marrow failure and infection.The telomere length of lymphocytes in the patient was significantly shorter than that of healthy controls of the same age,and the absolute value and percentage of lymphocyte subsets were abnormal.Conclusion The clinical manifestations of DC patients are diverse.Flow-FISH detection of telomere length is helpful for early diagnosis of DC patients.

Objective:To present a set of clinically representative quality assurance (QA) test cases for stereotactic radiosurgery (SRT) plans of multiple intracranial metastases, in order to assess the plan quality and machine execution capabilities.Methods:Based on the clinical characteristics of multiple brain metastases, four groups of test cases with three target volumes (TVs), six TVs, nine TVs, and TVs near organs at risk (OARs) were designed. For these cases, SRT plans were developed, and plan quality was assessed using metrics including the Radiation Therapy Oncology Group conformality index (RTOG CI), gradient index (GI), homogeneity index (HI), and the volume of normal brain tissue receiving a dose of 24 Gy ( V24 Gy), which was defined as the volume enclosed by the 24 Gy isodose line around the Brain-PTV ( V24 Gy of Brain-PTV). Verification plans were generated for each test case, including the verification of point doses, planar doses (PD), and SRS MapCHECK (SMC) semiconductor matrix planar doses. Compared with the calculated result of the treatment planning system (TPS), the criteria for the γ analysis of planar doses were set at 1 mm/2% and 2 mm/2%. Results:For the four groups of test cases, the mean CI, GI, HI, and V24 Gy of Brain-PTV were 1.04±0.03, 3.79±0.40, 0.73±0.01 and (7.46±3.80) cm 3, respectively. The mean deviations of the point doses were 0.88%±0.98%, 1.47%±0.79%, 1.52%± 0.76%, and 1.17% ± 0.38%, respectively. The mean γ passing rates of the single fields for PDs were greater than 98% at 2 mm/2% and exceeding 96% at 1 mm/2%, and the mean γ pass rates of the SMC semiconductor matrix for PDs were 97.75% ± 2.31% and 99.33% ± 0.62%, at 1 mm/2% and 2 mm/2% respectively. Conclusions:The proposed QA test cases for SRT of multiple intracranial metastases allow for the effective assessments of the plan quality and machine execution capabilities and, thus, can assist various centers in clinical applications.

Spectral computed tomography (CT) has triggered a technological revolution in radiodiagnosis while demonstrating its increasing application value in radiotherapy. Employing dual-energy techniques for material decomposition, spectral CT provides optimized solutions for several critical aspects of radiotherapy. Based on a review of the application situation of spectral CT in radiotherapy, this study delved into spectral CT′s significant advantages in image quality improvement, precise dose calculation, and comprehensive quantitative assessment. Furthermore, this study envisioned the development orientations and application prospects of spectral CT.

Pancreatic cancer is highly aggressive and often diagnosed at an advanced stage,leaving most patients ineligible for radical resection.This study retrospectively analyzed four patients with locally advanced or advanced pancreatic cancer to evaluate the clinical efficacy and safety of high-intensity focused ultrasound(HIFU)ablation combined with chemotherapy as a neoadjuvant and conversion therapy.All cases were reviewed and individualized treatment plans were formulated through a multidisciplinary team evaluation.All patients received HIFU plus gemcitabine and nab-paclitaxel chemotherapy,with assessments of tumor volume,vascular involvement,surgical conversion,symptom relief,and adverse events.Three patients achieved marked tumor shrinkage and reduction of vascular invasion,enabling successful R0 resection without recurrence during follow-up.The remaining patient achieved disease stability,significant pain relief,and maintained good quality of life under repeated HIFU therapy.All treatments were well tolerated,and no severe adverse reactions occurred.The combination of HIFU and chemotherapy demonstrated synergistic local and systemic effects,effectively achieving tumor downstaging,improving resectability,and alleviating symptoms.As a safe,noninvasive,and repeatable therapeutic approach,this strategy offers a promising option for patients with advanced pancreatic cancer.Further large-scale prospective studies are warranted to validate its long-term efficacy and elucidate underlying mechanisms.

Background and Aims:Infected necrotizing pancreatitis(INP),particularly with diffuse distribution,is a life-threatening condition.The optimal initial intervention-minimally invasive step-up therapy vs.direct open necrosectomy-remains controversial.Moreover,the impact of necrosis morphology("wet"or"dry")and the presence of severe acute pancreatitis(SAP)on treatment selection has not been fully clarified.This study aimed to compare the efficacy and safety of these two approaches in diffuse INP and to evaluate the guiding value of CT-based necrosis type and SAP status in clinical decision-making.Methods:A retrospective analysis was conducted on 458 patients with diffuse INP admitted to the Third Xiangya Hospital of Central South University from January 2012 to March 2023.Patients were divided into a minimally invasive step-up group(n=256)and a direct open surgery group(n=202).SAP was defined according to the determinant-based classification,and necrosis was categorized as"wet"or"dry"based on CT features.The primary endpoint was a composite of death or major complications,while secondary endpoints included mortality,length of hospital stay,and incision-related complications,were compared between the two groups,with subgroup analyses performed accordingly.Results:Overall,the open surgery group had higher rates of the primary endpoint(62.4%vs.48.1%,P=0.003)and mortality(27.2%vs.16.8%,P=0.008)compared with the step-up group.Among SAP patients,the step-up approach resulted in a significantly lower primary endpoint rate(66.7%vs.97.7%,P=0.003).In non-SAP patients,the primary endpoint rates were similar,but open surgery was associated with a shorter hospital stay[(36.5±10.4)d vs.(45.6±18.6)d,P<0.001]and higher incidences of wound infection and incisional hernia(both P<0.001).Multivariate analysis identified infection onset time,effusion characteristics,gas bubbles,and necrosis location as independent predictors of prolonged hospitalization in the step-up group(all P<0.05).Patients with"wet"necrosis benefited more from the step-up approach,whereas those with"dry"necrosis experienced shorter hospitalization following open surgery.Conclusion:For diffusely distributed INP,treatment strategies should be individualized based on SAP status and necrosis liquefaction/imaging characteristics.The step-up minimally invasive approach is preferred for SAP patients and those with"wet"necrosis on CT,while direct open necrosectomy may be advantageous for"dry"necrosis(particularly with limited liquefaction)by shortening hospital stay and reducing certain major outcomes,though at the cost of increased incision infection and incision herina.CT imaging features and SAP classification can serve as valuable tools for risk stratification and guiding individualized timing and modality of intervention.

Objective:To compare the immobilization effect of two different immobilization methods in treatment with CyberKnife for intracranial tumors.Methods:A retrospective analysis was conducted on 48 patients with intracranial tumors who received treatment with CyberKnife in the Department of Radiotherapy at Peking Union Medical College Hospital from June 2023 to July 2024.Based on the different immobilization method,patients were divided into two groups:the Double Shell Positioning System(DSPS)group(n=22)and the Qfix group(n=26).The DSPS group was immobilized using an American full-body integrated positioning frame combined with a carbon fiber bracket and DSPS film,while the Qfix group was immobilized using an Encompass board and Qfix film.All patients were treated with 6 dimensions(6D)-skull tracking technique.During treatment,images were acquired as one times per 60 seconds,which were registered with digitally reconstructed radiograph(DRR)to record and compare the overall relative errors.The data of relative displacement error during treatment was calculated as|dx|=d1-d0,and differences between the two groups were compared.The maximum displacement(|d|=dmax-dmin)was also calculated,and difference in maximum displacement between the two kinds of immobilization methods was analyzed.Results:In the comparison of the overall relative errors between the two kinds of immobilization methods,the median values in the errors of superior-inferior(SI),anterior-posterior(AP),Roll,Pitch,and Yaw directions in the Qfix group were respectively 0.174,0.309,0.150,0.147,and 0.477,which were significantly less than those(0.224,0.316,0.175,0.221,and 0.584)of DSPS group,and the differences were statistically significant(Z=-4.358,-1.698,-2.595,-6.833,-5.371,P<0.05).The difference of the relative displacement errors between two kinds of immobilization methods was not significant(P>0.05),while the median values in all directions were not zero.The comparison of the maximum displacement value between the two kinds of immobilization methods indicated the displacement amounts of Qfix group was less than those of DSPS group on SI,left-right(LR),AP,roll,pitch,and yaw directions,and the differences of them were significant(Z=-3.373,-2.525,-2.488,-3.169,-5.130,-5.166,P<0.05).Conclusion:Both immobilization methods can meet the requirements of clinical treatment.The results of comparison indicate the immobilization effect of Qfix group is best,and the combination of Encompass board and Qfix film is recommended as the immobilization method of CyberKnife-based radiotherapy for intracranial tumors.