Objective: The CT/MRI Liver Imaging Reporting and Data System (LI-RADS) demonstrates high specificity with relatively limited sensitivity for diagnosing hepatocellular carcinoma (HCC) in high-risk patients. This study aimed to explore the possibility of improving sensitivity by combining CT/MRI LI-RADS v2018 with second-line contrast-enhanced ultrasound (CEUS) LI-RADS v2017 using sulfur hexafluoride (SHF) or perfluorobutane (PFB). Materials and Methods: This retrospective analysis of prospectively collected multicenter data included high-risk patients with treatment-naive hepatic observations. The reference standard was pathological confirmation or a composite reference standard (only for benign lesions). Each participant underwent concurrent CT/MRI, SHF-enhanced US, and PFB-enhanced US examinations. The diagnostic performances for HCC of CT/MRI LI-RADS alone and three combination strategies (combining CT/ MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or a modified algorithm incorporating the Kupffer-phase findings for PFB [modified PFB]) were evaluated. For the three combination strategies, apart from the CT/MRI LR-5 criteria, HCC was diagnosed if CT/MRI LR-3 or LR-4 observations met the LR-5 criteria using LI-RADS SHF, LI-RADS PFB, or modified PFB. Results: In total, 281 participants (237 males; mean age, 55 ± 11 years) with 306 observations (227 HCCs, 40 non-HCC malignancies, and 39 benign lesions) were included. Using LI-RADS SHF, LI-RADS PFB, and modified PFB, 20, 23, and 31 CT/MRI LR-3/4 observations, respectively, were reclassified as LR-5, and all were pathologically confirmed as HCCs. Compared to CT/MRI LI-RADS alone (74%, 95% confidence interval [CI]: 68%–79%), the three combination strategies combining CT/MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or modified PFB increased sensitivity (83% [95% CI: 77%–87%], 84% [95% CI: 79%–89%], 88% [95% CI: 83%–92%], respectively; all P < 0.001), while maintaining the specificity at 92% (95% CI: 84%–97%). Conclusion The combination of CT/MRI LI-RADS with second-line CEUS using SHF or PFB improved the sensitivity of HCC diagnosis without compromising specificity.

Objective: The CT/MRI Liver Imaging Reporting and Data System (LI-RADS) demonstrates high specificity with relatively limited sensitivity for diagnosing hepatocellular carcinoma (HCC) in high-risk patients. This study aimed to explore the possibility of improving sensitivity by combining CT/MRI LI-RADS v2018 with second-line contrast-enhanced ultrasound (CEUS) LI-RADS v2017 using sulfur hexafluoride (SHF) or perfluorobutane (PFB). Materials and Methods: This retrospective analysis of prospectively collected multicenter data included high-risk patients with treatment-naive hepatic observations. The reference standard was pathological confirmation or a composite reference standard (only for benign lesions). Each participant underwent concurrent CT/MRI, SHF-enhanced US, and PFB-enhanced US examinations. The diagnostic performances for HCC of CT/MRI LI-RADS alone and three combination strategies (combining CT/ MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or a modified algorithm incorporating the Kupffer-phase findings for PFB [modified PFB]) were evaluated. For the three combination strategies, apart from the CT/MRI LR-5 criteria, HCC was diagnosed if CT/MRI LR-3 or LR-4 observations met the LR-5 criteria using LI-RADS SHF, LI-RADS PFB, or modified PFB. Results: In total, 281 participants (237 males; mean age, 55 ± 11 years) with 306 observations (227 HCCs, 40 non-HCC malignancies, and 39 benign lesions) were included. Using LI-RADS SHF, LI-RADS PFB, and modified PFB, 20, 23, and 31 CT/MRI LR-3/4 observations, respectively, were reclassified as LR-5, and all were pathologically confirmed as HCCs. Compared to CT/MRI LI-RADS alone (74%, 95% confidence interval [CI]: 68%–79%), the three combination strategies combining CT/MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or modified PFB increased sensitivity (83% [95% CI: 77%–87%], 84% [95% CI: 79%–89%], 88% [95% CI: 83%–92%], respectively; all P < 0.001), while maintaining the specificity at 92% (95% CI: 84%–97%). Conclusion The combination of CT/MRI LI-RADS with second-line CEUS using SHF or PFB improved the sensitivity of HCC diagnosis without compromising specificity.

Objective: The CT/MRI Liver Imaging Reporting and Data System (LI-RADS) demonstrates high specificity with relatively limited sensitivity for diagnosing hepatocellular carcinoma (HCC) in high-risk patients. This study aimed to explore the possibility of improving sensitivity by combining CT/MRI LI-RADS v2018 with second-line contrast-enhanced ultrasound (CEUS) LI-RADS v2017 using sulfur hexafluoride (SHF) or perfluorobutane (PFB). Materials and Methods: This retrospective analysis of prospectively collected multicenter data included high-risk patients with treatment-naive hepatic observations. The reference standard was pathological confirmation or a composite reference standard (only for benign lesions). Each participant underwent concurrent CT/MRI, SHF-enhanced US, and PFB-enhanced US examinations. The diagnostic performances for HCC of CT/MRI LI-RADS alone and three combination strategies (combining CT/ MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or a modified algorithm incorporating the Kupffer-phase findings for PFB [modified PFB]) were evaluated. For the three combination strategies, apart from the CT/MRI LR-5 criteria, HCC was diagnosed if CT/MRI LR-3 or LR-4 observations met the LR-5 criteria using LI-RADS SHF, LI-RADS PFB, or modified PFB. Results: In total, 281 participants (237 males; mean age, 55 ± 11 years) with 306 observations (227 HCCs, 40 non-HCC malignancies, and 39 benign lesions) were included. Using LI-RADS SHF, LI-RADS PFB, and modified PFB, 20, 23, and 31 CT/MRI LR-3/4 observations, respectively, were reclassified as LR-5, and all were pathologically confirmed as HCCs. Compared to CT/MRI LI-RADS alone (74%, 95% confidence interval [CI]: 68%–79%), the three combination strategies combining CT/MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or modified PFB increased sensitivity (83% [95% CI: 77%–87%], 84% [95% CI: 79%–89%], 88% [95% CI: 83%–92%], respectively; all P < 0.001), while maintaining the specificity at 92% (95% CI: 84%–97%). Conclusion The combination of CT/MRI LI-RADS with second-line CEUS using SHF or PFB improved the sensitivity of HCC diagnosis without compromising specificity.

Objective: The CT/MRI Liver Imaging Reporting and Data System (LI-RADS) demonstrates high specificity with relatively limited sensitivity for diagnosing hepatocellular carcinoma (HCC) in high-risk patients. This study aimed to explore the possibility of improving sensitivity by combining CT/MRI LI-RADS v2018 with second-line contrast-enhanced ultrasound (CEUS) LI-RADS v2017 using sulfur hexafluoride (SHF) or perfluorobutane (PFB). Materials and Methods: This retrospective analysis of prospectively collected multicenter data included high-risk patients with treatment-naive hepatic observations. The reference standard was pathological confirmation or a composite reference standard (only for benign lesions). Each participant underwent concurrent CT/MRI, SHF-enhanced US, and PFB-enhanced US examinations. The diagnostic performances for HCC of CT/MRI LI-RADS alone and three combination strategies (combining CT/ MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or a modified algorithm incorporating the Kupffer-phase findings for PFB [modified PFB]) were evaluated. For the three combination strategies, apart from the CT/MRI LR-5 criteria, HCC was diagnosed if CT/MRI LR-3 or LR-4 observations met the LR-5 criteria using LI-RADS SHF, LI-RADS PFB, or modified PFB. Results: In total, 281 participants (237 males; mean age, 55 ± 11 years) with 306 observations (227 HCCs, 40 non-HCC malignancies, and 39 benign lesions) were included. Using LI-RADS SHF, LI-RADS PFB, and modified PFB, 20, 23, and 31 CT/MRI LR-3/4 observations, respectively, were reclassified as LR-5, and all were pathologically confirmed as HCCs. Compared to CT/MRI LI-RADS alone (74%, 95% confidence interval [CI]: 68%–79%), the three combination strategies combining CT/MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or modified PFB increased sensitivity (83% [95% CI: 77%–87%], 84% [95% CI: 79%–89%], 88% [95% CI: 83%–92%], respectively; all P < 0.001), while maintaining the specificity at 92% (95% CI: 84%–97%). Conclusion The combination of CT/MRI LI-RADS with second-line CEUS using SHF or PFB improved the sensitivity of HCC diagnosis without compromising specificity.

Objective: The CT/MRI Liver Imaging Reporting and Data System (LI-RADS) demonstrates high specificity with relatively limited sensitivity for diagnosing hepatocellular carcinoma (HCC) in high-risk patients. This study aimed to explore the possibility of improving sensitivity by combining CT/MRI LI-RADS v2018 with second-line contrast-enhanced ultrasound (CEUS) LI-RADS v2017 using sulfur hexafluoride (SHF) or perfluorobutane (PFB). Materials and Methods: This retrospective analysis of prospectively collected multicenter data included high-risk patients with treatment-naive hepatic observations. The reference standard was pathological confirmation or a composite reference standard (only for benign lesions). Each participant underwent concurrent CT/MRI, SHF-enhanced US, and PFB-enhanced US examinations. The diagnostic performances for HCC of CT/MRI LI-RADS alone and three combination strategies (combining CT/ MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or a modified algorithm incorporating the Kupffer-phase findings for PFB [modified PFB]) were evaluated. For the three combination strategies, apart from the CT/MRI LR-5 criteria, HCC was diagnosed if CT/MRI LR-3 or LR-4 observations met the LR-5 criteria using LI-RADS SHF, LI-RADS PFB, or modified PFB. Results: In total, 281 participants (237 males; mean age, 55 ± 11 years) with 306 observations (227 HCCs, 40 non-HCC malignancies, and 39 benign lesions) were included. Using LI-RADS SHF, LI-RADS PFB, and modified PFB, 20, 23, and 31 CT/MRI LR-3/4 observations, respectively, were reclassified as LR-5, and all were pathologically confirmed as HCCs. Compared to CT/MRI LI-RADS alone (74%, 95% confidence interval [CI]: 68%–79%), the three combination strategies combining CT/MRI LI-RADS with either LI-RADS SHF, LI-RADS PFB, or modified PFB increased sensitivity (83% [95% CI: 77%–87%], 84% [95% CI: 79%–89%], 88% [95% CI: 83%–92%], respectively; all P < 0.001), while maintaining the specificity at 92% (95% CI: 84%–97%). Conclusion The combination of CT/MRI LI-RADS with second-line CEUS using SHF or PFB improved the sensitivity of HCC diagnosis without compromising specificity.

PURPOSE: To investigate the protective effect of sub-hypothermic mechanical perfusion combined with membrane lung oxygenation on ischemic hypoxic injury of yorkshire brain tissue caused by traumatic blood loss. METHODS: This article performed a random controlled trial. Brain tissue of 7 yorkshire was selected and divided into the sub-low temperature anterograde machine perfusion group (n = 4) and the blank control group (n = 3) using the random number table method. A yorkshire model of brain tissue injury induced by traumatic blood loss was established. Firstly, the perfusion temperature and blood oxygen saturation were monitored in real-time during the perfusion process. The number of red blood cells, hemoglobin content, NA⁺, K⁺, and Ca²⁺ ions concentrations and pH of the perfusate were detected. Following perfusion, we specifically examined the parietal lobe to assess its water content. The prefrontal cortex and hippocampus were then dissected for histological evaluation, allowing us to investigate potential regional differences in tissue injury. The blank control group was sampled directly before perfusion. All statistical analyses and graphs were performed using GraphPad Prism 8.0 Student t-test. All tests were two-sided, and p value of less than 0.05 was considered to indicate statistical significance. RESULTS: The contents of red blood cells and hemoglobin during perfusion were maintained at normal levels but more red blood cells were destroyed 3 h after the perfusion. The blood oxygen saturation of the perfusion group was maintained at 95% - 98%. NA⁺ and K⁺ concentrations were normal most of the time during perfusion but increased significantly at about 4 h. The Ca²⁺ concentration remained within the normal range at each period. Glucose levels were slightly higher than the baseline level. The pH of the perfusion solution was slightly lower at the beginning of perfusion, and then gradually increased to the normal level. The water content of brain tissue in the sub-low and docile perfusion group was 78.95% ± 0.39%, which was significantly higher than that in the control group (75.27% ± 0.55%, t = 10.49, p < 0.001), and the difference was statistically significant. Compared with the blank control group, the structure and morphology of pyramidal neurons in the prefrontal cortex and CA1 region of the hippocampal gyrus were similar, and their integrity was better. The structural integrity of granulosa neurons was destroyed and cell edema increased in the perfusion group compared with the blank control group. Immunofluorescence staining for glail fibrillary acidic protein and Iba1, markers of glial cells, revealed well-preserved cell structures in the perfusion group. While there were indications of abnormal cellular activity, the analysis showed no significant difference in axon thickness or integrity compared to the 1-h blank control group. CONCLUSIONS Mild hypothermic machine perfusion can improve ischemia and hypoxia injury of yorkshire brain tissue caused by traumatic blood loss and delay the necrosis and apoptosis of yorkshire brain tissue by continuous oxygen supply, maintaining ion homeostasis and reducing tissue metabolism level.
Animals ; Perfusion/methods* ; Disease Models, Animal ; Brain Injuries/etiology* ; Swine ; Male ; Hypothermia, Induced/methods*

Stem cell treatment may enhance erectile dysfunction (ED) in individuals with cavernous nerve injury (CNI). Nevertheless, no investigations have directly ascertained the implications of varying amounts of human umbilical cord-derived mesenchymal stem cells (HUC-MSCs) on ED. We compare the efficacy of three various doses of HUC-MSCs as a therapeutic strategy for ED. Sprague-Dawley rats (total = 175) were randomly allocated into five groups. A total of 35 rats underwent sham surgery and 140 rats endured bilateral CNI and were treated with vehicles or doses of HUC-MSCs (1 × 10 6 cells, 5 × 10 6 cells, and 1 × 10 7 cells in 0.1 ml, respectively). Penile tissues were harvested for histological analysis on 1 day, 3 days, 7 days, 14 days, 28 days, 60 days, and 90 days postsurgery. It was found that varying dosages of HUC-MSCs enhanced the erectile function of rats with bilateral CNI and ED. Moreover, there was no significant disparity in the effectiveness of various dosages of HUC-MSCs. However, the expression of endothelial markers (rat endothelial cell antigen-1 [RECA-1] and endothelial nitric oxide synthase [eNOS]), smooth muscle markers (alpha smooth muscle actin [α-SMA] and desmin), and neural markers (neurofilament [RECA-1] and neurogenic nitric oxide synthase [nNOS]) increased significantly with prolonged treatment time. Masson's staining demonstrated an increased in the smooth muscle cell (SMC)/collagen ratio. Significant changes were detected in the microstructures of various types of cells. In vivo imaging system (IVIS) analysis showed that at the 1 st day, the HUC-MSCs implanted moved to the site of damage. Additionally, the oxidative stress levels were dramatically reduced in the penises of rats administered with HUC-MSCs.
Male ; Animals ; Erectile Dysfunction/metabolism* ; Rats, Sprague-Dawley ; Mesenchymal Stem Cell Transplantation/methods* ; Rats ; Penis/pathology* ; Humans ; Disease Models, Animal ; Umbilical Cord/cytology* ; Peripheral Nerve Injuries/complications* ; Mesenchymal Stem Cells ; Nitric Oxide Synthase Type III/metabolism* ; Actins/metabolism* ; Nitric Oxide Synthase Type I/metabolism*

Hearing loss is the most prevalent disabling disease. Cochlear implantation（CI） serves as the primary intervention for severe to profound hearing loss. This consensus systematically explores the value of genetic diagnosis in the pre-operative assessment and efficacy prognosis for CI. Drawing upon domestic and international research and clinical experience, it proposes an evidence-based medicine three-tiered prognostic classification system（Favorable, Marginal, Poor）. The consensus focuses on common hereditary non-syndromic hearing loss（such as that caused by mutations in genes like GJB2, SLC26A4, OTOF, LOXHD1） and syndromic hereditary hearing loss（such as Jervell & Lange-Nielsen syndrome and Waardenburg syndrome）, which are closely associated with congenital hearing loss, analyzing the impact of their pathological mechanisms on CI outcomes. The consensus provides recommendations based on multiple round of expert discussion and voting. It emphasizes that genetic diagnosis can optimize patient selection, predict prognosis, guide post-operative rehabilitation, offer stratified management strategies for patients with different genotypes, and advance the application of precision medicine in the field of CI.
Humans ; Cochlear Implantation ; Prognosis ; Hearing Loss/surgery* ; Consensus ; Connexin 26 ; Mutation ; Sulfate Transporters ; Connexins/genetics*

Objective To optimize the platelet enrichment method,and to analyze the concentration changes of key molecules in platelet-rich plasma(PRP)before and after activation,as well as the impact of its activated products on the proliferation of rat endothelial progenitor cells.Methods The tube double-centrifu-gation method was employed to optimize platelet enrichment,and the platelet count in the enriched PRP was measured.ELISA was used to detect the concentration changes of vascular endothelial growth factor(VEGF),endostatin(ES),and P-selectin(CD62P)in PRP before and after activation.The PRP was activated by using liquid nitrogen freeze-thaw method,and the effect of its activated products on the proliferation of rat endothelial progenitor cells was evaluated by using the methyl thiazolyl tetrazolium(MTT)assay.Results The optimal enrichment coefficient of platelets achieved by the double-centrifugation method was 4.63.After low-speed,long-duration double centrifugation,the platelet count was highest in the upper layer of the buffy coat.For PRP with a platelet count of 500× 109/L obtained by machine collection,the VEGF con-centrations before and after activation were(3 418.12±488.80)pg/mL and(4 530.04±308.30)pg/mL,re-spectively,the ES concentrations were(6 168.98±253.22)pg/mL and(6 594.65±82.47)pg/mL,respec-tively,the CD62P concentrations were(6 678.23±324.15)pg/mL and(17 630.53±746.24)pg/mL,respec-tively,statistically significant differences were observed in the above indicators before and after activation(P＜0.01).The activated PRP was diluted in a gradient manner by using a specialized culture medium for en-dothelial progenitor cells.MTT assay results indicated that,in the basal medium,the optimal volume fraction for promoting endothelial progenitor cell proliferation was 0.25％after 48 hours of culture;in the complete medium,the optimal volume fractions for promoting endothelial progenitor cell proliferation were 0.062 5％after 24 hours and 0.125％after 48 hours.Conclusion The concentrations of VEGF,ES,and CD62P in the optimized,enriched PRP exhibited significant changes before and after activation.The optimal volume fraction for promoting endothelial progenitor cell proliferation in the basal medium was 0.25％.

Objective:To investigate the effect of abdominal circumference on intestinal radiation dose volume and acute intestinal toxicity in pelvic intensity modulated radiation therapy for rectal cancer.Methods:A total of 150 patients with locally advanced rectal cancer (LARC) who received adjuvant and neoadjuvant concurrent chemoradiotherapy at the Affiliated Cancer Hospital of Guizhou Medical University from March 2023 to January 2025 were enrolled, including 82 cases of adjuvant radiotherapy and 68 cases of neoadjuvant radiotherapy. All patients underwent radiotherapy CT simulation positioning in the standard mode of prone position with abdominal board padding and bladder filling. Intestinal toxicity was categorized as a binary variable based on the occurrence of ≥2 grade acute intestinal toxicity. Linear and logistic regression models were used to analyze the factors influencing intestinal radiation dose volumes (V 10, V 20, V 30, V 40) and acute intestinal toxicity in LARC patients. Generalized additive models and piecewise linear and logistic regression analyses were employed to examine the threshold effects of abdominal circumference on intestinal radiation dose volumes and acute intestinal toxicity. The threshold value for abdominal circumference was determined based on the upper limit of the 95% CI for the threshold. A difference test was used to validate the differences in intestinal radiation dose volume and acute intestinal toxicity between small and medium-to-large abdominal circumferences. Results:Univariate analysis showed that, gender, body mass, abdominal circumference, planning target volume (PTV), intestinal volume were all influencing factors for the radiation dose volumes (V 10, V 20, V 30, V 40) of each intestinal segment of patients with LARC undergoing adjuvant radiotherapy (all P<0.05). Body mass, abdominal circumference, intestinal volume were all influencing factors for the radiation dose volumes (V 10, V 20, V 30, V 40) of each intestinal segment of patients with LARC undergoing neoadjuvant radiotherapy (all P<0.05). Body mass index (BMI), abdominal circumference, intestinal volume and individual intestinal radiation volumes (V 10, V 20, V 30, V 40) were all influencing factors for the acute intestinal toxicity of patients with LARC undergoing adjuvant radiotherapy (all P<0.05). Body mass, BMI, abdominal circumference, multiple intestinal radiation dose volumes (V 20, V 30, V 40) were all influencing factors for the acute intestinal toxicity of patients with LARC undergoing neoadjuvant radiotherapy (all P<0.05). Multivariate analysis showed that, abdominal circumference (V 10: β=-1.01, 95% CI: -1.68--0.33, P=0.004; V 20: β=-0.94, 95% CI: -1.28--0.60, P<0.001; V 30: β=-0.58, 95% CI: -0.82--0.34, P<0.001; V 40: β=-0.41, 95% CI: -0.60--0.23, P<0.001) was an independent influencing factor for the radiation dose volume of each intestinal segment of patients with LARC undergoing adjuvant radiotherapy. Abdominal circumference (V 10: β=-0.92, 95% CI: -1.62--0.22, P=0.010; V 20: β=-0.84, 95% CI: -1.11--0.57, P<0.001; V 30: β=-0.42, 95% CI: -0.57--0.28, P<0.001; V 40: β=-0.30, 95% CI: -0.41--0.19, P<0.001) was an independent influencing factor for the radiation dose volume of each intestinal segment of patients with LARC undergoing neoadjuvant radiotherapy. Abdominal circumference ( OR=0.86, 95% CI: 0.78-0.95, P=0.002) was an independent influencing factor for the acute intestinal toxicity of patients with LARC undergoing adjuvant radiotherapy. Abdominal circumference ( OR=0.87, 95% CI: 0.79-0.96, P=0.004) was an independent influencing factor for the acute intestinal toxicity of patients with LARC undergoing neoadjuvant radiotherapy. The generalized additive model revealed a nonlinear relationship between abdominal circumference and intestinal radiation dose volume and acute intestinal toxicity of adjuvant radiotherapy patients. Further segmented regression analysis results showed that there was a threshold effect between abdominal circumference and intestinal radiation dose volume (V 10, V 20, V 30, V 40) and acute intestinal toxicity. The inflection point values between abdominal circumference and intestinal radiation dose volume V 10, V 20, V 30, V 40 in LARC patients undergoing adjuvant radiotherapy were all 71.9 cm; the inflection point values between abdominal circumference and the intestinal radiation dose volume V 10, V 20, V 30, V 40 in LARC patients undergoing neoadjuvant radiotherapy were 69.0, 69.0, 69.0, 68.6 cm, respectively; The inflection point values between abdominal circumference and acute intestinal toxicity in LARC patients undergoing adjuvant radiotherapy and neoadjuvant radiotherapy were 71.9, 69.0 cm, respectively. Based on the upper limit of the 95% CI threshold, the cutoff values for small and medium-to-large abdominal circumferences for patients undergoing adjuvant and neoadjuvant radiotherapy were set at 76.1, 71.9 cm, respectively. In patients undergoing adjuvant radiotherapy, the levels of intestinal radiation dose volume V 10 [ (7.65±2.29) cm 3vs. (5.88±2.68) cm 3, t=2.76, P=0.007], V 20 [ (4.28±1.27) cm 3vs. (2.72±1.31) cm 3, t=4.81, P<0.001], V 30 [ (2.42±1.07) cm 3vs. (1.37±0.76) cm 3, t=4.95, P<0.001], V 40 [ (1.69±0.74) cm 3vs. (0.92±0.58) cm 3, t=4.93, P<0.001] in the small abdominal circumference group ( n=22) were significantly higher than those in patients with medium-to-large abdominal circumferences ( n=60) ; In patients undergoing neoadjuvant radiotherapy, patients with small abdominal circumferences ( n=11) had significantly higher V 20 [ (3.09±0.84) cm 3vs. (2.28±1.17) cm 3, t=2.17, P=0.033], V 30 [1.44 (1.22, 1.53) cm 3vs. 0.91 (0.56, 1.22) cm 3, Z=-3.04, P=0.002], V 40 [0.93 (0.84, 1.09) cm 3vs. 0.44 (0.30, 0.81) cm 3, Z=-3.19, P=0.001] than patients with medium-to-large abdominal circumferences ( n=57). In patients receiving adjuvant radiotherapy and neoadjuvant radiotherapy, there were statistically significant differences in acute intestinal toxicity between patients with small abdominal circumferences and with medium-to-large abdominal circumferences ( χ2=10.46, P=0.001; χ2=8.13, P=0.004) . Conclusions:In the standard mode (prone position with abdominal board padding and bladder filling), abdominal circumference is an independent factor influencing the intestinal radiation dose volume and acute intestinal toxicity in rectal cancer radiotherapy patients. There is a significant non-linear threshold effect between abdominal circumference and different levels of intestinal radiation dose volume and acute intestinal toxicity. The impact of abdominal circumference on intestinal radiation dose volume and toxicity differs significantly before and after the inflection point value. Patients with smaller abdominal circumferences not only fail to achieve the expected benefits under the current standard radiotherapy regimen but also face higher risks of intestinal radiation dose volume and toxicity.