Objective:To explore the application process, efficacy and safety of MR-guided radiotherapy based on MR-linac in esophageal cancer.Methods:The clinical data of patients with esophageal cancer treated with MR-linac at Shandong Cancer Hospital and Institute from September 2021 to July 2022 were retrospectively analyzed, to investigate the treatment process of esophageal cancer with MR-linac, and to analyze the efficacy and safety of patients. All patients received MR-guided radiotherapy, underwent CT and MR localization, target area delineation, and design of the Monaco treatment planning system plan. Adaptation-to-position adjustment was conducted during the pre-treatment evaluation. The median number of fractions was 25, the median single dose of planning target volume was 1.8 Gy, and the median total dose was 50.2 Gy. Median follow-up was 16 months.Results:Among the 12 patients in the whole group, there were 1 case of cervical esophageal cancer, 3 cases of upper thoracic esophageal cancer, 4 cases of middle thoracic esophageal cancer and 4 cases of lower thoracic esophageal cancer, including 3 cases of neoadjuvant radiotherapy and 9 cases of radical radiotherapy. All patients had a smooth treatment process. The median treatment time was 33 min, and the patients had good compliance. For patients with radical radiotherapy, one month after radiotherapy, the number of objective remission cases was 3, and the number of disease-control cases was 9; six months after radiotherapy, the number of objective remission cases was 3, and the number of disease-control cases was 6. All patients treated with neoadjuvant radiotherapy underwent surgery within 2 months, and one patient achieved pathological complete remission. The most common acute adverse reactions were radiation esophagitis (7 cases) and leukopenia in bone marrow suppression (8 cases), with late-stage adverse reactions being radiation pneumonia (1 case). The adverse reactions to radiotherapy were slight, and no grade 4 or above adverse reactions were observed.Conclusion:The clinical treatment process for esophageal cancer under MR-guided radiotherapy based on MR-linac is feasible, with good curative effects and mild adverse reactions.

Objective To investigate the evaluation of the nursing staff of the tertiary hospitals in Shenzhen City on the status quo of the nursing clinical support system,and to analyze its influencing factors so as to provide reference and basis for perfecting the nursing clinical support system.Methods The nursing staffs in 16 hospitals of 8 districts of Shenzhen City from December 2022 to January 2023 were selected as the survey subjects,and the general data questionnaire and the nursing clinical support system questionnaire were used for conducting the survey.Results A total of 572 questionnaires were collected,and 520 questionnaires were valid,with an effective recovery rate of 90.9％.The scores of each dimension in the nursing clinical sup-port system scale were(1.87±0.81)points for equipment and appliance support,(1.07±0.62)points for aux-iliary staff support,(1.91±0.80)points for the logistics departments support,(0.88±0.67)points for the auxiliary departments support.The results of univariate analysis showed that there were statistical differences in the equipment and appliance support scores among the nurses with different ages,different professional ti-tles and different education levels(P＜0.01);the scores of 4 dimensions had statistical differences among the nursing staffs with different departments(P＜0.01).All factors had statistically significant differences in the dimension of auxiliary department support(P＜0.05).Conclusion The popularity degree of nursing clinical support system in tertiary hospitals in Shenzhen City is high,and equipment and appliance show the character-istics of advancement and diversity.The hospital managers should strengthen the force of nursing clinical sup-port system and reduce the nursing staff to engage in non-nursing work.

Brachytherapy is irreplaceable in definitive radiotherapy and postoperative radiotherapy for cervical cancer. Since the vagina is adjacent to the cervix in terms of anatomical position and the vaginal applicator is placed in the vagina between the bladder and the rectum, the absorbed dose of the vagina is extremely uneven and difficult to evaluate. This review expounds the present vaginal side effects, vaginal dose evaluation method, dose-effect relationship between dose and side effects, and dose limits in brachytherapy for cervical cancer, to provide a certain reference for the clinical practice of the brachytherapy for cervical cancer.

Brachytherapy plays an important role in radical radiotherapy of cervical cancer. At present, most hospitals in China use high-dose-ate brachytherapy, which irradiatevolume by simulating line source with a single approximate point source. Therefore, the dwell positions and dwell times can be optimized appropriately. However, due to various reasons, the initial state of the optimization plan must start from the standard loading pattern, and ensure that the optimized plan basically maintains the pear-shaped dose distribution. This paper introduces the standard loading pattern of intracavitary brachytherapy and intracavitary combined interstitial brachytherapy for cervical cancer through literature review, and expounds the planning optimization model and the constraints in the optimization process, to provide important reference for the planning of brachytherapy for cervical cancer.

Proline-rich transmembrane protein 2 (PRRT2) is the leading cause of paroxysmal kinesigenic dyskinesia (PKD), benign familial infantile epilepsy (BFIE), and infantile convulsions with choreoathetosis (ICCA). Reduced penetrance of PRRT2 has been observed in previous studies, whereas the exact penetrance has not been evaluated well. The objective of this study was to estimate the penetrance of PRRT2 and determine its influencing factors. We screened 222 PKD index patients and their available relatives, identified 39 families with pathogenic or likely pathogenic (P/LP) PRRT2 variants via Sanger sequencing, and obtained 184 PKD/BFIE/ICCA families with P/LP PRRT2 variants from the literature. Penetrance was estimated as the proportion of affected variant carriers. PRRT2 penetrance estimate was 77.6% (95% confidence interval (CI) 74.5%-80.7%) in relatives and 74.5% (95% CI 70.2%-78.8%) in obligate carriers. In addition, we first observed that penetrance was higher in truncated than in non-truncated variants (75.8% versus 50.0%, P = 0.01), higher in Asian than in Caucasian carriers (81.5% versus 68.5%, P = 0.004), and exhibited no difference in gender or parental transmission. Our results are meaningful for genetic counseling, implying that approximately three-quarters of PRRT2 variant carriers will develop PRRT2-related disorders, with patients from Asia or carrying truncated variants at a higher risk.
Dystonia ; Epilepsy, Benign Neonatal/genetics* ; Humans ; Membrane Proteins/genetics* ; Mutation ; Nerve Tissue Proteins/genetics* ; Pedigree ; Penetrance ; Seizures/genetics*

Objective:To summarize and analyze the clinical data of Chinese patients with colony-stimulating factor 1 receptor (CSF1R)-related leukoencephalopathy, and clarify the phenotypic and genetic characteristics of Chinese patients.Methods:Medical history of patients with CSF1R-related leukoencephalopathy diagnosed from April 1, 2018 to January 31, 2021 in the department of neurology of 22 hospitals in China was collected, and scores of Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment Scale (MoCA), magnetic resonance severity scale were evaluated. Group comparison was performed between male and female patients.Results:A total of 62 patients were included, and the male-female ratio was 1∶1.95. The age of onset was (40.35±8.42) years. Cognitive impairment (82.3%, 51/62) and motor symptoms (77.4%,48/62) were the most common symptoms. The MMSE and MoCA scores were 18.79±7.16 and 13.96±7.23, respectively, and the scores of two scales in male patients (22.06±5.31 and 18.08±5.60) were significantly higher than those in females (15.53±7.41 , t=2.954, P=0.006; 10.15±6.26, t=3.328 , P=0.003). The most common radiographic feature was bilateral asymmetric white matter changes (100.0%), and the magnetic resonance imaging severity scale score was 27.42±11.40, while the white matter lesion score of females (22.94±8.39) was significantly higher than that of males (17.62±8.74 , t=-2.221, P<0.05). A total of 36 CSF1R gene mutations were found in this study, among which c.2381T>C/p.I794T was the hotspot mutation that carried by 17.9% (10/56) of the probands. Conclusions:The core phenotypic characteristics of CSF1R-related leukoencephalopathy in China are progressive motor and cognitive impairment, with bilateral asymmetrical white matter changes. In addition, there exist gender differences clinically, with severer cognitive impairment and imaging changes in female patients. Thirty-six CSF1R gene mutations were found in this study, and c.2381T>C/p. I794T was the hotspot mutation.

Objective:To measure the effect of applicator materials on absorbed dose in water from HDR afterloading 192Ir source by using three-dimensional printed holder (3DPH) and synthetic single-crystal diamond detector (SSCDD). Methods:SSCDD and plastic implants were fixed on the 3DPH in turn. The central axis of SSCDD was perpendicular to that of plastic implant needle on the same plane. The actual residence dwell position measured using source position simulator was 248 mm, which was consistent with the maximum response dwell position measured in a point by point way. The materials for measurement included 304 stainless steel, polyphenylene sulfone resins (PPSU), polymethyl methacrylate (PMMA) and 3-D printed polylactic acid (PLA), respectively. The attenuation of absorbed dose in water with different thickness or filling ratio was measured.Results:The linear fitting formula of relative dose varying with thickness (mm) for 304 stainless steel and PPSU materials were y=-0.029 7 x+ 1.000 3 and y=-0.002 3 x + 1.010 2, respectively. And the goodness-of-fits were 0.925 3 and 0.722 2, respectively. The effect on dose of PMMA materials within 10 mm was less than 1%. The linear fitting formula of relative dose varying with filling ratio (%) for PLA materials with 10 mm thickness was y=-0.000 4 x+ 1.024 6, with a goodness-of-fit of 0.854 5. Conclusions:The effect of applicator materials on the absorbed dose arising from afterloading 192Ir source should attract enough attention of both developers and clinical users, especially with regard to high-density materials like 304 stainless steel and new technology materials such as 3D printed polylactic acid.

Stereotactic body radiotherapy (SBRT) has become an important radiotherapy technology. In recent years, with the continuous improvement of the mechanical properties of the linear accelerator (LINAC), LINAC-based SBRT is gradually emerging. In this article, the history, technological progress, radiation physics, clinical application of LINAC-based SBRT were elaborated, aiming to promote the development of LINAC-based SBRT.

Objective:To explore the application of 3D printing technology-assisted standardized applicator in the image-guided adaptive brachytherapy (IGABT) for cervical cancer.Methods:Twenty-three patients with stage Ⅲ B cervical cancer with extensive paracervical invasion after external irradiation (45 Gy/25f) were treated with IGABT, and the prescription dose was 7 Gy/f×4f. According to the regression of tumor on MRI before and after external irradiation, the range of brachytherapy was determined, and the under dose area of standard intracavitary/interstitial applicator (IC+ IS) was estimated. The virtual transperineal needle channel was inserted in the under dose area, the angle, spacing and depth of implantation were optimized. The auxiliary templates were designed with graphic design software, and 3D printing technology was utilized to print the auxiliary templates. The auxiliary templates were closely combined with the standardized applicator. Under the anesthesia condition, ultrasound-guided applicator was completed, and patients were scanned with MRI image after operation. The MRI images were introduced into treatment planning system (TPS) to delineate the target area and organs at risk, and the treatment plans were optimized to complete the plan evaluation and treatment. Results:The average printing time of templates was (3.5±1.0) h, 382 implant needles were inserted guided by auxiliary templates, (4.2±1.5) template-guided implant needles were used in each fraction and the weight ratio was (16.49±9.50)%. The total dose of HR-CTV D 90% EQD 2Gy, α/ β=10 was (90.45±3.03) Gy, and IR-CTV D 90% EQD 2Gy, α/ β=10 was (66.46±3.68) Gy. The D 2cm 3 EQD 2Gy, α/ β=3 of the bladder, rectum, small intestine and sigmoid colon were (82.69±2.60) Gy, (73.20±2.52) Gy, (69.35±3.32) Gy and (69.39±3.27) Gy, respectively, all of which met the clinical dose requirements. The 1-and 2-year local control rates were 96% and 87%, 87% and 70% for the distant metastasis-free survival rates, and 96% and 78% for thea overall survival rates, respectively. Conclusion:The auxiliary applicators made by 3D printing technology can effectively compensate for the dose insufficiency of the standard applicator in the paracervical and other areas during the clinical brachytherapy in patients with stage Ⅲ B cervical cancer, providing an effective method for the brachytherapy of advanced cervical cancer.

In China, COVID-19 epidemic is currently showing a sporadic state, and the task of epidemic prevention is still arduous. Brachytherapy (BT) plays a critical role in the treatment of cancer. For some cancer receiving radiotherapy, use of BT can not be replaced or excessively delayed. Nevertheless, the recommendations or guidelines regarding the application of BT during COVID-19 epidemic have been rarely reported. In this article, a few recommendations on the application of BT during COVID-19 epidemic were retrieved and the work experience of Department of Radiation Oncology, China-Japan Union Hospital of Jilin University in the early epidemic period was summarized, aiming to provide relevant reference for the use of high-dose-rate BT for malignant tumor patients during COVID-19 epidemic.