Objective:To investigate whether ultra-high dose rate (FLASH) irradiation can reduce radiation-induced intestinal injuries of mice compared to conventional dose rate (CONV) irradiation.Methods:Both FLASH and CONV irradiation were delivered with electron beam, with dose rates of 750 Gy/s and 0.5G y/s, respectively. A total of 105 mice were randomly divided into groups using a simple randomization method. Twenty-one mice were selected for weight observation, 7 mice in each group. After 9 Gy FLASH and CONV irradiation on the abdomen, the weight changes of mice were measured every other day, and compared among three groups. Twenty-four mice were selected for pathological examination including 5 mice in the control group. Three-and-a-half-day days after 12 Gy FLASH ( n=10) and CONV irradiation ( n=9) on the abdomen, the intestines of the mice were taken. Pathological sections were stained with hematoxylin-eosin (HE) to compare the number and percentage of regenerated crypts of the small intestine between two groups. After 12 Gy FLASH ( n=10) and CONV irradiation ( n=10) on the abdomen, the survival of 20 mice was observed. After FLASH using 4.5 Gy×2 times ( n=10) and CONV irradiation at 9 Gy×1 time ( n=10) on the abdomen, the weight changes were observed. After FLASH using 6 Gy×2 times ( n=10) and CONV irradiation at 12 Gy×1 time ( n=10) on the abdomen, the survival of mice was observed. The time interval between two irradiation was 1 min. EBT3 film was employed to monitor the actual exposure dose of the mice. The variables conforming to normal distribution were expressed by Mean±SD. Inter group comparison was performed by independent t-test. The survival of mice among different groups was compared by log-rank test. Results:After 9 Gy of abdominal irradiation, the mean weight of mice in the FLASH group was significantly higher than that in the CONV group. The weight of mice in the FLASH and CONV groups was (19.8±0.8) g and (18.0±1.8)g ( P=0.036) at 7 days after irradiation, (22.0±1.0)g and (21.2±0.5)g ( P=0.075) at 15 days after irradiation, and (24.2±1.4)g and (22.0±1.2)g ( P=0.012) at 25 days after irradiation, respectively. After 12 Gy irradiation, the mean survival of mice in FLASH and CONV groups was 4 days and 4.7 days ( P=0.029). After 12 Gy total abdominal irradiation, the mean number of intestinal regenerative crypts in the FLASH and CONV groups was 2.9/mm and 1.2/mm ( P=0.041), and the percentage of intestinal regenerative crypts was 34.1% and 14.1%, respectively. The survival of mice irradiated by FLASH using 6 Gy×2 times was longer compared with that of mice after CONV irradiation at 12 Gy×1 time. The weight of mice after 4.5 Gy×2 times irradiation was higher than that of mice after CONV irradiation at 9 Gy×1 time. Conclusion:Weight, survival and the number of intestinal regenerative crypts in the FLASH group are higher than those in the CONV group after irradiation, indicating that radiation-induced intestinal injury caused by FLASH irradiation is slighter than that of CONV irradiation.

Radiotherapy is one of the important treatment modalities for malignant tumors. Conventional fractionation is the most commonly-used radiotherapy mode, but it has disadvantages such as long treatment time and low efficiency, etc. With the advancement of radiotherapy equipment and technology, moderately hypofractionated radiotherapy has become the standard treatment for tumors such as breast cancer and prostate cancer, etc. However, the efficacy and safety of moderately hypofractionated radiotherapy have not been fully confirmed in a wider range of tumors. In this article, the application, efficacy, and safety of moderately hypofractionated radiotherapy in malignant tumors were reviewed.

Alzheimer's disease is a serious neurodegenerative disease without effective treatment. In recent years, researchers have tried to treat Alzheimer's disease with low-dose radiation therapy (LDRT) and have made some progress in animal models and clinical trials. Current studies have shown that LDRT can improve cognitive function in Alzheimer's patients by reducing β amyloid plaque deposition and reducing inflammation levels in central nervous system. In this review, we present the current preclinical and clinical studies, propose the possible mechanisms of LDRT in Alzheimer's disease, and discuss challenges in the planning of future trials.

Objective: To investigate the correlation between tumor size, tumor location, and prognosis in patients with early-stage endometrial cancer (EC) receiving adjuvant radiotherapy. Methods: Data of patients who had been treated for stage I–II EC from March 1999 to September 2017 in 13 tertiary hospitals in China was screened. Cox regression analysis was performed to investigate associations between tumor size, tumor location, and other clinical or pathological factors with cancer-specific survival (CSS) and distant metastasis failurefree survival (DMFS). The relationship between tumor size as a continuous variable and prognosis was demonstrated by restricted cubic splines. Prognostic models were constructed as nomograms and evaluated by Harrell’s C-index, calibration curves and receiver operating characteristic (ROC) curves. Results: The study cohort comprised 805 patients with a median follow-up of 61 months and a median tumor size of 3.0 cm (range 0.2–15.0 cm). Lower uterine segment involvement (LUSI) was found in 243 patients (30.2%). Tumor size and LUSI were identified to be independent prognostic factors for CSS. Further, tumor size was an independent predictor of DMFS. A broadly positive relationship between poor survival and tumor size as a continuous variable was visualized in terms of hazard ratios. Nomograms constructed and evaluated for CSS and DMFS had satisfactory calibration curves and C-indexes of 0.847 and 0.716, respectively. The area under the ROC curves for 3- and 5-year ROC ranged from 0.718 to 0.890. Conclusion Tumor size and LUSI are independent prognostic factors in early-stage EC patients who have received radiotherapy. Integrating these variables into prognostic models would improve predictive ability.

Objective: To investigate the correlation between tumor size, tumor location, and prognosis in patients with early-stage endometrial cancer (EC) receiving adjuvant radiotherapy. Methods: Data of patients who had been treated for stage I–II EC from March 1999 to September 2017 in 13 tertiary hospitals in China was screened. Cox regression analysis was performed to investigate associations between tumor size, tumor location, and other clinical or pathological factors with cancer-specific survival (CSS) and distant metastasis failurefree survival (DMFS). The relationship between tumor size as a continuous variable and prognosis was demonstrated by restricted cubic splines. Prognostic models were constructed as nomograms and evaluated by Harrell’s C-index, calibration curves and receiver operating characteristic (ROC) curves. Results: The study cohort comprised 805 patients with a median follow-up of 61 months and a median tumor size of 3.0 cm (range 0.2–15.0 cm). Lower uterine segment involvement (LUSI) was found in 243 patients (30.2%). Tumor size and LUSI were identified to be independent prognostic factors for CSS. Further, tumor size was an independent predictor of DMFS. A broadly positive relationship between poor survival and tumor size as a continuous variable was visualized in terms of hazard ratios. Nomograms constructed and evaluated for CSS and DMFS had satisfactory calibration curves and C-indexes of 0.847 and 0.716, respectively. The area under the ROC curves for 3- and 5-year ROC ranged from 0.718 to 0.890. Conclusion Tumor size and LUSI are independent prognostic factors in early-stage EC patients who have received radiotherapy. Integrating these variables into prognostic models would improve predictive ability.

Objective: To investigate the correlation between tumor size, tumor location, and prognosis in patients with early-stage endometrial cancer (EC) receiving adjuvant radiotherapy. Methods: Data of patients who had been treated for stage I–II EC from March 1999 to September 2017 in 13 tertiary hospitals in China was screened. Cox regression analysis was performed to investigate associations between tumor size, tumor location, and other clinical or pathological factors with cancer-specific survival (CSS) and distant metastasis failurefree survival (DMFS). The relationship between tumor size as a continuous variable and prognosis was demonstrated by restricted cubic splines. Prognostic models were constructed as nomograms and evaluated by Harrell’s C-index, calibration curves and receiver operating characteristic (ROC) curves. Results: The study cohort comprised 805 patients with a median follow-up of 61 months and a median tumor size of 3.0 cm (range 0.2–15.0 cm). Lower uterine segment involvement (LUSI) was found in 243 patients (30.2%). Tumor size and LUSI were identified to be independent prognostic factors for CSS. Further, tumor size was an independent predictor of DMFS. A broadly positive relationship between poor survival and tumor size as a continuous variable was visualized in terms of hazard ratios. Nomograms constructed and evaluated for CSS and DMFS had satisfactory calibration curves and C-indexes of 0.847 and 0.716, respectively. The area under the ROC curves for 3- and 5-year ROC ranged from 0.718 to 0.890. Conclusion Tumor size and LUSI are independent prognostic factors in early-stage EC patients who have received radiotherapy. Integrating these variables into prognostic models would improve predictive ability.

Objective:To evaluate and summarize the teaching effect of" New Technology of Radiotherapy and Oncology" in the form of questionnaire, understand the degree of demand for the course of all kinds of medical students and improve the teaching contents and methods.Methods:The course of" New Technology of Radiotherapy and Oncology" was a specialized elective course in Peking Union Medical College. After two rounds of teaching practices, we evaluated the students participating in the course or non-course participants by anonymous questionnaire. The questionnaire items include the course content, setting, teachers and improvement suggestions.Results:A total of 73 questionnaires were sent out, and the recovery rate was 100%. Among them, 52(71%) were from students who chose the courses. 83% of the students" strongly agree" that the teaching content of this course is the latest development, the latest achievement or the problem to be solved, 94% were" satisfied" or" very satisfied" with their learning effect, and 92% and 83% were satisfied with the teachers and teaching plan, respectively. After taking the course, students rated" broadening of mind" (96%) as the biggest gain, followed by" facilitating interdisciplinary collaboration" (79%). 86% of the non-course participants felt the need to supplement the existing curriculum with new techniques in oncology radiotherapy, hoping that the curriculum would" broaden the mind" (76%), improve clinical application (81%) and facilitate interdisciplinary collaboration (71%).Conclusion:The questionnaire results show that the teaching practice of this course covers the different needs of all kinds of students, which is worthy of implementation and further improvement.

Objective:To assess the value of culture of epidermal melanocytes from negative-pressure suction blisters in the auxiliary diagnosis of segmental vitiligo-like nevus depigmentosus.Methods:Between June 2019 and March 2020, 8 patients with segmental vitiligo-like nevus depigmentosus, who met the Coupe′s clinical diagnostic criteria, were enrolled from Department of Dermatology, Hangzhou Third People′s Hospital. All patients were evaluated by the Wood′s lamp, reflectance confocal microscopy (RCM) , 308-nm excimer laser radiation, and in vitro culture of epidermal melanocytes from negative-pressure suction blisters. Results:Among the 8 patients, fluorescence was observed in 6 under the Wood′s lamp, dermal papillary rings were incomplete or absent in 4 as shown by RCM, and 5 experienced no repigmentation after 308-nm excimer laser radiation. Among the 8 patients, in vitro cultured lesional melanocytes were all positive for ferrous sulfate staining, yellowish-white precipitates were obtained after digestion and centrifugation of the melanocytes, and stage Ⅰ-Ⅲ melanosomes were observed in the cytoplasm of melanocytes under the electron microscope; however, the precipitates were black in color after digestion and centrifugation of the melanocytes collected from the normal skin tissues at the contralateral anatomical site, and stageⅠ-Ⅳ melanosomes were seen in the cytoplasm of the melanocytes under the electron microscope. Conclusion:Culture of epidermal melanocytes from negative-pressure suction blisters may facilitate the diagnosis of segmental vitiligo-like nevus depigmentosus.

Objective:The investigation and research on the application status of Hepatic Venous Pressure Gradient (HVPG) is very important to understand the real situation and future development of this technology in China.Methods:This study comprehensively investigated the basic situation of HVPG technology in China, including hospital distribution, hospital level, annual number of cases, catheters used, average cost, indications and existing problems.Results:According to the survey, there were 70 hospitals in China carrying out HVPG technology in 2021, distributed in 28 provinces (autonomous regions and municipalities directly under the central Government). A total of 4 398 cases of HVPG were performed in all the surveyed hospitals in 2021, of which 2 291 cases (52.1%) were tested by HVPG alone. The average cost of HVPG detection was (5 617.2±2 079.4) yuan. 96.3% of the teams completed HVPG detection with balloon method, and most of the teams used thrombectomy balloon catheter (80.3%).Conclusion:Through this investigation, the status of domestic clinical application of HVPG has been clarified, and it has been confirmed that many domestic medical institutions have mastered this technology, but it still needs to continue to promote and popularize HVPG technology in the future.

Objective:To study the feasibility of using pelvic iterative cone beam CT images for dose calculation of radiation therapy planning, so as to provide support for adaptive radiotherapy.Methods:The CIRS 062 M phantom was scanned by Varian Halcyon v2.0 o-ring accelerator, and the average CT number under different scattering conditions was calculated, and then the ICBCT-ED conversion curve was established. CT images of CIRS 002PRA pelvic IMRT phantom and ICBCT images at different positions were collected. Treatment plan using VMAT technique based on CT image was designed and transplanted into ICBCT image with dose recalculated. The differences of gamma passing rate among target volume, organs at risk and 3-dimensional dose were compared. Based on the actual treatment plan of patients, the differences of 3-dimensional dose gamma passing rate in 10 pelvic patients were analyzed retrospectively.Results:There was a large CT value deviation at central position between the isolated no-scattering condition and the full-scattering condition, and the maximum deviation was 144 HU. The CT values of other positions in full-scattering condition were similar to those of the central position, and the maximum deviation was less than 50 HU. Based on the calculated result of ICBCT images at different positions of the pelvic phantom, the dose deviation of the target volume or organs at risk was less than 1 Gy. Compared with the plan based on CT images, the average 3-dimensional dose gamma passing rate under the criteria of 1% dose difference (DD)/1 mm distance-to-agreement (DTA) and 2% DD/2 mm DTA in plan based on ICBCT images were (88.86 ±1.18)% and (98.38±0.89)%, respectively. The ranges of average 3-dimensional dose gamma passing rate under the criteria of 2% DD/2 mm DTA and 3% DD/3 mm DTA in 10 patients with pelvic tumors were 90.03%-95.43% and 93.58%-97.78%, respectively, and the worst result was only 85.90% and 92.90%, respectively. The main reason of the worst result was the dose difference caused by large variation of bladder contour due to over-filling.Conclusions:Under comprehensive scattering conditions, the ICBCT-ED conversion curve is reconstructed and the treatment plan can be designed by using the ICBCT image of Halcyon v2.0 linear accelerator. The accuracy meets the standards of clinical application, which provides assurance for adaptive radiotherapy in the future.