Objective To evaluate the application of three deep learning algorithms in automatic segmentation of clinical target volumes (CTVs) in high-dose-rate brachytherapy after surgery for endometrial carcinoma. Methods A dataset comprising computed tomography scans from 306 post-surgery patients with endometrial carcinoma was divided into three subsets: 246 cases for training, 30 cases for validation, and 30 cases for testing. Three deep convolutional neural network models, 3D U-Net, 3D Res U-Net, and V-Net, were compared for CTV segmentation. Several commonly used quantitative metrics were employed, i.e., Dice similarity coefficient, Hausdorff distance, 95th percentile of Hausdorff distance, and Intersection over Union. Results During the testing phase, CTV segmentation with 3D U-Net, 3D Res U-Net, and V-Net showed a mean Dice similarity coefficient of 0.90 ± 0.07, 0.95 ± 0.06, and 0.95 ± 0.06, a mean Hausdorff distance of 2.51 ± 1.70, 0.96 ± 1.01, and 0.98 ± 0.95 mm, a mean 95th percentile of Hausdorff distance of 1.33 ± 1.02, 0.65 ± 0.91, and 0.40 ± 0.72 mm, and a mean Intersection over Union of 0.85 ± 0.11, 0.91 ± 0.09, and 0.92 ± 0.09, respectively. Segmentation based on V-Net was similarly to that performed by experienced radiation oncologists. The CTV segmentation time was < 3.2 s, which could save the work time of clinicians. Conclusion V-Net is better than other models in CTV segmentation as indicated by quantitative metrics and clinician assessment. Additionally, the method is highly consistent with the ground truth, reducing inter-doctor variability and treatment time.

Objective To investigate the clinical characteristics and dosimetric parameters associated with acute hematologic toxicity (AHT) resulting from radiation-induced damage to hematopoietic organs in patients undergoing chemoradiotherapy for cervical cancer and to provide a reference for establishing dose constraints in relevant regions of interest (ROIs) and predicting adverse tissue reactions during the development of clinical treatment plans. Methods A retrospective analysis was conducted on 556 patients with cervical cancer who underwent chemoradiotherapy at our hospital. Univariate (χ² and t-test) and multivariate (binary logistic regression analyses) methods were employed to investigate the association of clinical factors and pelvic dose-volume parameters with grade ≥ 3 AHT in patients with cervical cancer. Clinical factors comprised patients’ age, clinical stage, pathologic stage, whether the patient had received chemotherapy in the radiotherapy cycle of interest, and dose-volume dosimetric parameters V_x and D_mean for pelvic bone marrow (BM) and femoral head (FH) structures. Results The incidence of AHT among the included cases was 30.4% (169/556). Chi-square analysis of the clinical factors revealed that whether the patient had received chemotherapy, patient’s age, and pathologic stage had a significant impact on AHT. Univariate analysis showed that the factors associated with AHT were mean dose, V₅, V₁₀, V₁₅, V₂₀, and V₂₅ of BM and FH; dosimetric parameters such as V₃₅ of FH had a significant impact on the development of AHT. Multivariate logistic regression analysis identified V₁₅ of pelvic BM as an independent risk factor for AHT (P=0.041), with a threshold value of 84.29% as determined by a receiver operating characteristic (ROC) curve. Conclusion Whether a patient had received chemotherapy in the radiotherapy cycle of interest, and patient’s age and pathologic stage can serve as predictors of AHT. V₁₅ of BM is an independent risk factor for AHT development. Therefore, when formulating a treatment plan, it is crucial to ensure that pelvic V₁₅ remains below 84.29% to effectively reduce the incidence of grade ≥ 3 acute bone marrow depression.

Objective To explore the feasibility of quartz glass for radiotherapy dosimetry through the experimental study of the thermoluminescence characteristics of synthetic quartz glass. Methods The thermoluminescence glow curves of quartz glass under different annealing conditions were analyzed, the thermoluminescence characteristics of quartz glass were studied, and the measurement parameters were optimized. Using the Co-60 reference radiation field in the National Secondary Standard Dosimetry Laboratory, the quartz glass samples under different annealing conditions were irradiated following the dose levels of radiotherapy, i.e., 0.5, 1.0, 2.0, 4.0, 6.0, 8.0, and 10.0 Gy, respectively. According to the relationship between the absorbed dose of quartz glass and the relative thermoluminescence signal intensity, the linearity and dispersion of the dose response of quartz glass were obtained, and the feasibility of quartz glass for radiotherapy dosimetry was analyzed. Results The linear correlation coefficient of dose response of quartz glass under annealing condition of 430℃ for 10 min was 0.9984, and the dose response dispersion was 0.97% at the absorbed dose of 2 Gy. The linear correlation coefficient of dose response of quartz glass under annealing condition of 600℃ for 1 h was 0.9911, and the dose response dispersion was 1.4% at the absorbed dose of 2 Gy. Conclusion Preliminary results suggest that quartz glass with annealing condition of 430℃ for 10 min has the potential to be used for radiotherapy dosimetry.

Objective:To evaluate the efficacy and safety of nonsurgical methods in early postnatal correction of congenital auricle malformation.Methods:The clinical trials regarding non-surgical treatment for congenital ear deformity published before May 2021 were searched in databases of Cochrane Library, PubMed, Medline, CNKI, VIP and Wanfang. The information of included studies was extracted. The Meta-analysis was performed by using RevMan 5.3 software.Results:A total of 15 trials were included, involving 1 349 patients. The Meta-analysis results showed that the effect of the group <6 weeks was better than the group over 6 weeks ( OR=4.67, 95% CI: 3.21, 6.78, Z=8.09, P<0.001); The complications incidence of the group < 6 weeks was lower than the group over 6 weeks ( OR=0.27, 95% CI: 0.08, 0.88, Z=2.18, P=0.03); The correction time required of the group <6 weeks was shorter than the group over 6 weeks ( MD=-11.81, 95% CI: -18.36, -5.26, Z=3.54, P=0.001). Conclusions:Non-surgical correction of congenital ear malformation within 6 weeks after birth has better efficacy and safety.

Objective To calculate the energy dependence of absorbed dose in EBT3 film, and to reveal the error in the measurement of proton absorbed dose by EBT3 film. Methods Beam energy was gradually increased in the clinical photon and proton energy ranges. Geant4 was used to calculate the difference in absorbed dose between EBT3 film and the same volume of water. The results were compared with the theoretical values. Results For photons and protons, the thresholds for absorbed dose with energy dependence were 100 keV and 11 MeV, respectively. The energy dependence was consistent with the theoretical values when the photon and proton energies were higher than the corresponding thresholds, and irrelevant to the theoretical values when energies were lower than the thresholds. The differences between the proton Bragg peak and 50% dose point and the actual positions were less than 1%. Conclusions For protons and photons with high energy, the energy dependence of absorbed dose in EBT3 film is negligible. For protons and photons with low energy, EBT3 film shows very different energy dependence of absorbed dose, which should be taken into consideration. The proton Bragg peak and 50% dose point measured by EBT3 film are basically the same as the actual positions.

Objective:To preliminarily disclose the biological properties of recombinant human tau441 (P301S) protein, such as aggregation, antigenicity and immunogenicity.Methods:The recombinant plasmid tau441 (P301S) was expressed by prokaryotic expression system and purified by nickel column affinity chromatography. The protein concentrations were determined via BCA kit. The purity of protein was determined by SDS-PAGE gel coomassie brilliant blue staining. Western blot (WB) and negative staining transmission electron microscopy (TEM) were used to identify the recombinant proteins. The antigenicity was detected through indirect enzyme linked immunosorbent assay (ELISA), and the immunogenicity was detected by specific antibody titers of mouse immune serum.Results:The purity of recombinant human tau441 (P301S) was 70%. WB showed specific bands at relative molecular mass (Mr.×10 3) 64 and higher relative molecular mass. Negative staining TEM showed that tau441 (P301S) was aggregated, and the area was significantly larger than tau wild-type control protein (t=6.439, P=0.003). After 9 days of incubation at 4 ℃, tau441 (P301S) formed obvious fibrotic structure. Indirect ELISA result showed that tau441 (P301S) could be recognized by anti-tau monoclonal antibody HT7 (1∶80 000). The specific antibody titer of the immunized serum was 1∶128 000 and WB showed that the immunized serum recognized the brain lysate extract of Alzheimer’s disease (AD) transgenic mice. Conclusions:The recombinant human tau441 (P301S) protein had the characteristics of enhanced aggregation in vitro, but its antigenicity and immunogenicity were not changed.

It was generally believed that muscular atrophy of paralyzed limbs after stroke was due to disuse. However, recent studies have found that secondary lesions of motor neurons in the contralateral anterior horn of the spinal cord and the decrease of motor units lead to denervation, which plays an essential role in muscular atrophy and muscle fiber type transition. This article reviews the phenomenon and mechanism of muscular atrophy and denervation of paralyzed limbs after stroke, to provide a reference for clinical evaluation and experimental research.

Objective: To retrospectively analyze the efficacy and prognostic factors of postoperative intensity modulated radiotherapy for grade Ⅱ gliomas. Methods: Retrospective analysis was conducted on patients with postoperative grade Ⅱ glioma in our hospital from Jan. 2010 to Dec. 2018. The primary endpoint was progression-free survival, and the secondary endpoint was overall survival. Correlative analyses of prognosis by age, gender, initial resection status, the maximum diameter of the lesions, bi-hemisphere, astrocytoma, chemoradiation, adjuvant chemotherapy were conducted. Results: A total of 109 cases with grade Ⅱ glioma were enrolled. The follow-up rate was 91.75%, including 10 cases dead and 27 relapsed. There were 24 cases (88.9%) of in-field failure, and 3 cases (11.1%) of out-field failure. 14 cases of recurrence occurred in 81 cases of total resection group, accounting for 17.3%, and 13 in 28 cases of subtotal resection group, accounting for 46.4%. The recurrence rate in the subtotal resection group was significantly higher than that in the total resection group (χ ²=9.484, P<0.05). The 1-, 2-, 3-, 4- and 5-year progression-free survival rates were 92.5%, 86.0%, 80.6%, 77.5% and 66.8%, respectively. The 2-, 3-, 4- and 5-year overall survival rates were 97.2%, 90.8%, 87.7% and 84.5%, respectively. Multivariate analysis showed that patients with subtotal resection(HR=3.608, P<0.05) and bi-hemisphere(HR=3.183, P<0.05)were significantly correlated with the progression free survival. Conclusions Postoperative intensity modulated radiotherapy for grade Ⅱ gliomas can achieve a better PFS. Recurrence in the radiation field is the main failure mode. Initial resection status and bi-hemisphere of tumor are important influential factors for PFS of grade Ⅱ gliomas patients.

OBJECTIVETo explore the relationship between the distributions of posterior ramus of spinal nerve (PRSN) and locations of acupoint in low back through anatomical observation.

METHODSThe regional anatomy was performed at five corpses to observe the distribution of erector spinae muscle and PRSN in areas ofpoints and back-points in low back.

RESULTSThe T, L, L, Land LPRSN distributed on both sides of the spine; the medial branches of PRSN travelled between spinalis thoracis muscle and longissimus thoracis muscle, while the lateral branches of PRSN travelled between longissimus thoracis muscle and iliocostalis lumborum muscle.

CONCLUSIONS points and back-points in low back are closely associated with PRSN, particularly T, L, L, Land L.

Objective To explore the neurovascular distribution around multifidus muscles in the low back and its clinical significance via regional dissection.Methods Five cadavers were dissected in the low back.The anatomical relationships between the longissimus thoracis,iliocostalis and the start-stop,direction and position of multifidus muscles were observed.Branches,distribution and the characteristics of the erector spinae muscle,the lateral branches of spinal nerves and blood vessels were examined.Then measured the distances from the emerging point of the lateral cutaneous branches of spinal nerves to the spinous processes.Results After removed the deep fascia,the longissimus thoracis was found medially and the iliocostalis was found laterally.The muhifidus muscles located deeply to the longissimus and the iliocostalis muscles.The lateral branches of the posterior rami of the spinal nerves and the dorsal branches of lumbar blood vessels run in the multifidus muscle gaps.Conclusion The multifidus muscle gaps contain plenty of neurovascular bundles.Surgery involving the low back often takes the advantage of the gaps between multifidus muscles.Therefore,surgeons should take caution to avoid damaging the lateral branches of the posterior rami of the spinal nerves and the dorsal branches of lumbar vessels during low back surgery.