Objective To quantitatively assess the correlation between the skeletal muscle index(SMI)of patients and the occur-rence of anastomotic leakage(AL)in rectal cancer patients after surgery,and to analyze the risk factors for AL in rectal cancer patients and the influencing factors of sarcopenia.Methods The clinical,pathological,and related imaging data of 362 patients who under-went radical surgery for rectal cancer were retrospectively analyzed.All patients underwent pelvic MRI and abdominal CT scans(plain/enhanced)within one month before surgery,and the third lumbar vertebra skeletal muscle area(L3-SMA)was measured from the images.All patients were divided into AL group(56 cases)and control group(306 cases)based on the presence or absence of postoperative complications.The differences in clinical characteristics and imaging parameters between the two groups were analyzed.A logistic risk prediction model was established.Results Significant differences were observed between the two groups in sarcopenia,type of surgery,surgical approach,serum albumin level,operation duration,stoma type,and extramural vascular invasion(EMVI)(P＜0.05).These factors were incorporated in a multivariate logistic regression analysis model,the area under the curve(AUC)of receiver operating characteristic(ROC)curve of the model was 0.810[95％confidence interval(CI)0.743-0.876,P＜0.001],with a sensitivity of 0.865 and specificity of 0.669.Conclusion Sar-copenia is a significant risk factor for AL after rectal cancer surgery.It enhances the predictive efficacy for postoperative AL and serves as a basis for identifying high-risk populations for AL in clinical practice.

Immunotherapy for cancer,as an emerging treatment modality,has made significant strides in recent years and has become a crucial therapeutic approach following surgery,radiotherapy,chemotherapy,and targeted therapy.In particular,the clinical utilization of immune checkpoint inhibitors(ICIs)has not only enhanced the survival rates of patients with refractory or recurrent tumors but has also significantly optimized the overall strategy for cancer treatment.However,as the population undergoing cancer immunotherapy continues to grow,this expansion not only yields clinical benefits but also precipitates a range of specific adverse reactions known as immune-related adverse events(irAEs).Pleural effusion is a common and severe complication in cancer patients,significantly affecting both their quality of life and treatment outcomes.Typically,tumor-related pleural effusion is often due to pleural metastasis,with malignant pleural effusion(MPE)characterized by rapid growth,being difficult to control,and tendency for recurrence.With the approval of new drugs and the expansion of indications for existing medications,the number of cancer patients receiving ICIs treatment is increasing,bringing ICIs-related pleural effusion into focus.While ICIs treatment-related pleural effusion is relatively rare in clinical practice,it is closely linked to treatment choices of patients and prognosis.Unlike MPE,the pathogenesis of ICIs treatment-related pleural effusion is more complex,not only involving non-specific immune activation leading to autoimmune inflammatory reactions but also potentially related to nodular pleural granulomatous reactions,eosinophilic chronic pleurisy,and tumor-infiltrating lymphocytes.In terms of diagnosis,ICIs treatment-related pleural effusion is typically diagnosed through exclusion,requiring the exclusion of other causes such as tumor progression,radiotherapy,and chemotherapy-induced pleural effusion,adding complexity and difficulty to the diagnostic process.Treatment for ICIs treatment-related pleural effusion often involves glucocorticoids,tocilizumab,or infliximab,aiming to alleviate symptoms and improve prognosis by suppressing excessive immune reactions.Preventing the occurrence of ICIs treatment-related pleural effusion is equally crucial,necessitating comprehensive patient assessment before ICIs administration and continuous monitoring during treatment to promptly detect and manage potential adverse reactions.Through this comprehensive management approach,the impact of ICIs treatment-related pleural effusion on patient quality of life and treatment outcomes can be minimized,optimizing overall treatment results.This review aimed to explore the pathogenesis,histological features,clinical manifestations,diagnostic methods and treatment strategies of ICIs treatment-related pleural effusion,and delve into the characteristics of ICIs treatment-related pleural effusion,in order to enhance understanding of this complication and provide a reference for clinical practice.

Tumor deposits(TD)is one of the independent risk factors for poor prognosis of colorectal cancer.The diagnosis of TD primarily relied on postoperative pathology,and precise preoperative assessment was difficult to achieve.With the development of medical imaging,many imaging techniques and analyzing methods had been applied to explore TD in colorectal cancer.The progresses in imaging research of TD in colorectal cancer were reviewed in this article.

Objective:To analyze the learning curve of TiRobot-assisted lumbar pedicle screw fixation (LPSF) by cumulative sum (CUSUM) test method.Methods:The clinical data of 50 patients who underwent TiRobot-assisted LPSF from January 2020 to December 2022 in Beijing Friendship Hospital, Capital Medical University were retrospectively analyzed. CUSUM analysis and learning curve fitting were performed with robot usage time as the main indicator with the time for each step refined (robot registration time, path planning time and guide wire placement time), to select the best learning curve fitting model with the R2 value closest to 1. Using the turning point of the learning curve as the boundary, the learning curve was divided into two stages as learning stage and maturity stage, and then the observation indexes were compared between the two stages. Results:All 50 patients successfully completed the surgery without perioperative complications, with a total of 244 pedicle screws implanted. The total robot usage time and robot registration time showed a gradually decreasing trend with the increase of case number, and the learning curves were successfully fitted and reached their peaks at the seventeenth and thirteenth cases respectively. The entire learning process was divided into learning stage (17 cases) and maturity stage (33 cases) based on the turning point of the learning curve of total robot usage time. The path planning time and guide wire placement time did not show significant changes with the increase in the case number. The total robot usage time, robot registration time and the intraoperative blood loss in the learning stage were significantly higher than those in the maturity stage: (35.35 ± 1.58) min vs. (30.61 ± 0.43) min, (20.83 ± 1.56) min vs. (14.94 ± 0.29) min and 400 (150, 500) ml vs. 200 (110, 300) ml, the guide wire placement time of per screw was significantly lower than that in the maturity stage: 2.00 (1.83, 2.34) min/screw vs. 2.33 (2.13, 2.69) min/screw, and there were statistical differences ( P<0.05 or <0.01). There were no statistical difference in the path planning time, path planning time of per screw, guide wire placement time and the accuracy of screw placement between two stages ( P>0.05). Conclusions:TiRobot-assisted LPSF is a new technology with safety and effectiveness, and it has a relatively short learning curve. To achieve technological maturity, at least 17 surgeries are required with accumulated experience, and the robot registration is the main step of the learning process. After reaching maturity stage, the robot usage time is significantly shortened and intraoperative trauma is significantly reduced while the relatively high screw placement accuracy is ensured.

Objective To quantitatively assess the correlation between the skeletal muscle index(SMI)of patients and the occur-rence of anastomotic leakage(AL)in rectal cancer patients after surgery,and to analyze the risk factors for AL in rectal cancer patients and the influencing factors of sarcopenia.Methods The clinical,pathological,and related imaging data of 362 patients who under-went radical surgery for rectal cancer were retrospectively analyzed.All patients underwent pelvic MRI and abdominal CT scans(plain/enhanced)within one month before surgery,and the third lumbar vertebra skeletal muscle area(L3-SMA)was measured from the images.All patients were divided into AL group(56 cases)and control group(306 cases)based on the presence or absence of postoperative complications.The differences in clinical characteristics and imaging parameters between the two groups were analyzed.A logistic risk prediction model was established.Results Significant differences were observed between the two groups in sarcopenia,type of surgery,surgical approach,serum albumin level,operation duration,stoma type,and extramural vascular invasion(EMVI)(P＜0.05).These factors were incorporated in a multivariate logistic regression analysis model,the area under the curve(AUC)of receiver operating characteristic(ROC)curve of the model was 0.810[95％confidence interval(CI)0.743-0.876,P＜0.001],with a sensitivity of 0.865 and specificity of 0.669.Conclusion Sar-copenia is a significant risk factor for AL after rectal cancer surgery.It enhances the predictive efficacy for postoperative AL and serves as a basis for identifying high-risk populations for AL in clinical practice.

Purpose To develop and validate a nomogram incorporating high-resolution MRI and clinicopathological indicators for predicting distant metastasis after curative resection of mid-low rectal cancer.Materials and Methods This retrospective study analyzed 219 patients with pathologically confirmed mid-low rectal cancer from Tianjin Union Medical Center(December 2016 to December 2021).Patients were categorized into metastasis(n=46)and non-metastasis(n=173)groups based on postoperative distant metastasis occurrence.All patients underwent preoperative pelvic MRI with measurement of posterior mesangial thickness(PMT),mesentery fat area(MFA)and mesenteric fascia envelopment volume(MFEV)on high-resolution T2WI.Clinicopathological and imaging data were collected.Cox proportional hazards model identified predictive factors for distant metastasis,and a risk probability nomogram was constructed.Predictive performance,goodness-of-fit and clinical applicability were evaluated.Results Kaplan-Meier analysis demonstrated significantly higher distant metastasis risk in patients with PMT≤1.43 cm,MFA≤19.31 cm2 and MFEV≤137.46 cm3 compared to those with higher values(χ2=29.07,8.71,19.05;all P<0.05).Cox regression identified tumor differentiation(HR=0.536,95％CI 0.290-0.990),pathological N stage(HR=0.397,95％CI 0.210-0.747),perirectal structure invasion(HR=0.242,95％CI 0.068-0.865)and PMT(HR=0.334,95％CI 0.168-0.664)as independent predictors.The nomogram achieved a concordance index of 0.775 with good calibration.Decision curve analysis demonstrated substantial net benefit across wide probability thresholds,indicating excellent clinical applicability.Conclusion Patients with PMT≤1.43 cm,MFA≤19.31 cm2 and MFEV≤137.46 cm3 exhibit elevated distant metastasis risk.The nomogram incorporating tumor differentiation,pathological N stage,perirectal structure invasion and PMT effectively predicts distant metastasis after curative resection of mid-low rectal cancer.

Objective To investigate the differences of condylar position in patients with temporomandibular disorders(TMD),and to further explore the effects of condylar position displacement and malocclusion factors on TMD.Methods According to the inclusion criteria,normal occlusion subjects without TMD(group A,n=10),normal occlusion subjects with TMD(group B,n=8),malocclu-sion subjects without TMD(group C,n=9)and malocclusion subjects with TMD(group D,n=20)were collected.Condylar position measurement(CPM)and Cadiax Ⅳ were used to locate the position of condyle in RP and ICP,and the displacement and direction of condyle in three-dimensional direction from RP to ICP were measured by vernier caliper.All the data were averaged three times and an-alyzed by SPSS26.0 statistical software.Results In the sagittal direction,the condylar displacement of group A and group B,group C and group D,and group A and group D had statistical differences(P＜0.01).The displacement of the right condyle in the vertical direc-tion of group D was greater than that of group A,and the difference was statistically significant(P＜0.05).The difference among other groups was not statistically significant.There was no significant difference in the lateral displacement of condyle between the four groups.In group A and group D,the largest proportion of condyle deviation was anterior up,while in group B and group C,the largest proportion of condyle deviation was posterior up.Conclusion RP-ICP condylar sagittal displacement is common in people with TMD.The condyle displacement of RP-ICP in malocclusion patients without TMD is not significantly different from that in normal occlusion patients without TMD.Patients with TMD malocclusion are more likely to have condylar displacement in sagittal direction and vertical direction than normal occlusion without TMD.

Purpose To develop and validate a nomogram incorporating high-resolution MRI and clinicopathological indicators for predicting distant metastasis after curative resection of mid-low rectal cancer.Materials and Methods This retrospective study analyzed 219 patients with pathologically confirmed mid-low rectal cancer from Tianjin Union Medical Center(December 2016 to December 2021).Patients were categorized into metastasis(n=46)and non-metastasis(n=173)groups based on postoperative distant metastasis occurrence.All patients underwent preoperative pelvic MRI with measurement of posterior mesangial thickness(PMT),mesentery fat area(MFA)and mesenteric fascia envelopment volume(MFEV)on high-resolution T2WI.Clinicopathological and imaging data were collected.Cox proportional hazards model identified predictive factors for distant metastasis,and a risk probability nomogram was constructed.Predictive performance,goodness-of-fit and clinical applicability were evaluated.Results Kaplan-Meier analysis demonstrated significantly higher distant metastasis risk in patients with PMT≤1.43 cm,MFA≤19.31 cm2 and MFEV≤137.46 cm3 compared to those with higher values(χ2=29.07,8.71,19.05;all P<0.05).Cox regression identified tumor differentiation(HR=0.536,95％CI 0.290-0.990),pathological N stage(HR=0.397,95％CI 0.210-0.747),perirectal structure invasion(HR=0.242,95％CI 0.068-0.865)and PMT(HR=0.334,95％CI 0.168-0.664)as independent predictors.The nomogram achieved a concordance index of 0.775 with good calibration.Decision curve analysis demonstrated substantial net benefit across wide probability thresholds,indicating excellent clinical applicability.Conclusion Patients with PMT≤1.43 cm,MFA≤19.31 cm2 and MFEV≤137.46 cm3 exhibit elevated distant metastasis risk.The nomogram incorporating tumor differentiation,pathological N stage,perirectal structure invasion and PMT effectively predicts distant metastasis after curative resection of mid-low rectal cancer.

Objective:In carbon ion treatment planning of water phantom, establish a conversion factor calculation system and conversion factor curves for organs at risk (OAR) for microdosimetric kinetic models (MKM) and local effect models (LEM), and validate them in clinical patient planning.Methods:Using a uniform spherical water phantom as the research object, relative biological effectiveness-weighted doses (RWD) for the LEM were re-calculated based on the physical dose of RayStation-MKM. The median dose within the planning target volume (PTV) of LEM and MKM was regarded as the conversion factor. The impacts of single-fraction target prescription dose, spread-out Bragg peak (SOBP) width and depth, shape, and irradiation mode on the conversion factor were assessed, and a conversion factor calculation system was established. Additionally, the accuracy of the conversion factor calculation system was validated using both water phantoms and clinical patient cases. The conversion factor curves for OAR were computed based on clinical patient treatment plans.Results:The primary influencing factors for the conversion factors were the single-fraction prescription dose, target SOBP width and depth. The conversion factors were increased with the increase of SOBP width and target depth, whereas decreased with the increase of the single-fraction prescription dose. Under single-field irradiation, a conversion factor calculation system was established based on above 3 parameters. For the plans of 9 patients, the average difference between the calculated results and the conversion factor calculation system was 0.340% ± 0.203%, and the average difference in the conversion curves for OAR was 2.650% ± 2.399%.Conclusion:A dose conversion factor calculation system and conversion factor curves for OAR for carbon ion radiotherapy are established for MKM and LEM, and their accuracy meets the requirements for use in clinical patient treatment plans.