The feasibility study on the generalization of deep learning dose prediction model for volumetric modulated arc therapy of cervical cancer.

PURPOSE: To develop a 3D-Unet dose prediction model to predict the three-dimensional dose distribution of volumetric modulated arc therapy (VMAT) for cervical cancer and test the dose prediction performance of the model in endometrial cancer to explore the feasibility of model generalization. METHODS: One hundred and seventeen cases of cervical cancer and 20 cases of endometrial cancer treated with VMAT were used for the model training, validation, and test. The prescribed dose was 50.4 Gy in 28 fractions. Eight independent channels of contoured structures were input to the model, and the dose distribution was used as the output of the model. The 3D-Unet prediction model was trained and validated on the training set (n = 86) and validation set (n = 11), respectively. Then the model was tested on the test set (n = 20) of cervical cancer and endometrial cancer, respectively. The results between clinical dose distribution and predicted dose distribution were compared in the following aspects: (a) the mean absolute error (MAE) within the body, (b) the Dice similarity coefficients (DSCs) under different isodose volumes, (c) the dosimetric indexes including the mean dose (Dmean ), the received dose of 2 cm3 (D2cc) , the percentage volume of receiving 40 Gy dose of organs-at-risk (V40 ), planning target volume (PTV) D98% , and homogeneity index (HI), (d) dose-volume histograms (DVHs). RESULTS: The model can accurately predict the dose distribution of the VMAT plan for cervical cancer and endometrial cancer. The overall average MAE and maximum MAE for cervical cancer were 2.43 ± 3.17% and 3.16 ± 4.01% of the prescribed dose, respectively, and for endometrial cancer were 2.70 ± 3.54% and 3.85 ± 3.11%. The average DSCs under different isodose volumes is above 0.9. The predicted dosimetric indexes and DVHs are equivalent to the clinical dose for both cervical cancer and endometrial cancer, and there is no statistically significant difference. CONCLUSION: A 3D-Unet dose prediction model was developed for VMAT of cervical cancer, which can predict the dose distribution accurately for cervical cancer. The model can also be generalized for endometrial cancer with good performance.

American older adults in COVID-19 Times: Vulnerability types, aging attitudes and emotional responses

BackgroundThe coronavirus disease aroused challenges to the emotional well-being of vulnerable older adults in hard-hit areas. This study investigates different vulnerability types among American older adults and how modes of vulnerability are associated with aging attitudes and emotional responses. MethodsUsing Latent Class Analysis, we investigated 2003 respondents aged over 50 from HRS. Hierarchical linear regressions with the affective profile as cluster identity were used to examine the relationship between vulnerability type and positive aging attitudes with positive and negative emotional responses. ResultsWe detected three vulnerability types among American older adults: the slight vulnerability (72%), the healthcare use vulnerability (19%), and the dual vulnerabilities (9%). No significant difference in positive emotions was found between vulnerability types. However, more negative emotions were found among older adults with healthcare use vulnerability (B=0.746, SE=0.759) and dual vulnerabilities (B=1.186, SE=0.274) than those with slight vulnerability. Positive aging attitudes associate with more positive emotions (B=0.266, SE=0.017) but less negative emotions (B=-0.183, SE=0.016) and had significant moderation effects on the relationship between vulnerability types and negative emotional responses (B=-0.118, SE=0.045). ConclusionOlder adults emotional well-being should not be neglected as they deserve the support of prevention and intervention strategies, in particular when they have vulnerabilities in healthcare use and financial sustainment. Female, non-white races, and those aged below 65, been uncoupled, less educated, and with ADL difficulties should prioritize.

The feasibility study of generalization of knowledge-based planning for cervical cancer / 中华放射医学与防护杂志

Objective:To design a knowledge-based cervical cancer planning model and apply it to cases of endometrial cancer and rectal cancer in order to explore the generalization of the model.Methods:A total of 179 cases of pelvic regions with different prescribed doses of dual-arc volumetric modulated arc therapy clinical plans were collected, of which 99 cases of cervical cancer clinical plans with a prescribed dose of 50.4 Gy were used as the training set to establish the RapidPlan model, and the remaining clinical plans were divided into 4 validation groups with 20 cases in each group. The clinical plans for cervical cancer and endometrial cancer with a prescription dose of 50.4 Gy were named groups A and B, while the clinical plan for endometrial cancer and rectal cancer with a prescription dose of 45 Gy were named groups C and D. The model was used to redesign the clinical plans in the 4 groups and the automatic plans were obtained. The planning target volume (PTV) and organ at risk (OAR) dosimetry parameters were compared between automatic plans and clinical plans.Results:The conformity index (CI) of the automatic plans in the A, B, C, and D groups were equivalent to that of the clinical plans ( P>0.05). The homogeneity index (HI) and D2% of the automatic plans in groups A, B, and C were all lower than those in clinical plans(HI, Z=-3.248, -3.360, -2.329, P<0.05; D2%, Z=-2.987, -3.397, -2.442, P<0.05). The HI and D2% of the automatic plans in group D were similar those in the clinical plans ( P>0.05). While ensuring the PTV coverage, the average value of OAR dosimetry parameters in all automatic plans groups were lower than that of the clinical plans. Conclusions:The RapidPlan model established by the cervical cancer clinical plans can complete the automatic plan design for endometrial cancer and rectal cancer under different prescription doses, which preliminarily proves the possibility of the generalization of the RapidPlan model.

Research progress on automatic treatment planning methods for radiotherapy / 中华放射肿瘤学杂志

The design of a conventional radiotherapy plan is a time-consuming and labor-intensive process, and relevant parameters need to be continuously adjusted in the plan optimization to identify the optimal plan. In addition, experience differences between planners, time invested in plan design, and institutional standards all affect the quality of the plan, which in turn influences clinical outcomes and patient prognosis. In recent years, automatic planning has developed rapidly, which can improve the efficiency of planning design while ensuring the quality of the plan. At present, there are several methods dedicated to the automation of radiotherapy planning design, such as the Rapid Plan and Auto-Planning functions in Eclipse and Pinnacle commercial treatment planning systems, and there are also studies applying artificial intelligence technology in dose prediction to achieve automatic planning. In this article, the research progress on automatic radiotherapy planning was reviewed, and the realization principles, clinical efficacy and existing problems of various automatic planning methods were illustrated.

Survey and Reflection on the Ethical Cognition of Human Sperm Bank among Sperm Donors / 中国医学伦理学

Objective:To investigate the ethical cognition of human sperm among the volunteers who intend to donor sperm,and to analyze the voluntteers' thoughts for donor behavior and its countermeasures.Methods:A questionnaire survey was conducted to investigate the volunteers who were the first time consulted sperm donation in the human sperm bank of the affiliated reproductive hospital of Shandong university.The cognition on the purpose of sperm,the causes of sperm shortage,privacy protection of the offspring,and the future of sperm banks in China were collected.Results:Donors were not well known the uses of sperm and privacy protection of the offspring.They thought traditional values and ethical worry caused sperm shortage and worried about the future of human sperm banks in China.Conclusion:The overall cognition on the sperm bank of the volunteers still exist certain one-sidedness and blind,which has seriously affected the enthusiasm of volunteers to donate sperm.The relevant departments should pay more attention to this,focus on promoting the propaganda and supervision work of ethical system of human sperm bank,construct objective,justice,and dedicative atmosphere for sperm donation,in order to dispel the volunteers' psychological concerns,and promote the healthy,fast and sustainable development of human sperm bank.

Incentive mechanism and implications of orphan drug market in the United States / 中国卫生政策研究

Serious market failure, as a result of insufficient incentive, exists in the orphan drugs market. Through legislation, the United States designed and established its owns systematic and linked orphan drugs incentive mechanism, which direct sat research, definition, clinical trials and approval of orphan drugs, so as to change the supply and demand status of orphan drugs. Such incentive mechanism erables the United States possess the most ap-proved orphan drugs in the world, and effectively relieves the problem of market failure of the orphan drugs. The ex-perience of the United States provides beneficial reference for the establishment and positive development of orphan drugs incentive mechanism in China.

The impact of dean's characteristics on the competitiveness of private hospitals：Based on a study of 100 private hospital data / 中国卫生政策研究

This paper selects the characteristics of hospital deans as a starting point to study the influence of private hospital competitiveness .According to the competitiveness of the private hospitals 100 list in Hong Kong , Eric Peter Hospital Management Research Center released in 2014 , regard the list derived competitiveness evaluation score as the independent variable , and according to the manual excerpt from hospital official website and publicly available information ,the Author has calculated the sample characteristics data of the list of 100 private hospitals and other con-trol variables .Research results demonstrate that private hospital deans 'age distribution structure is too large , and the average years of work in the health care practice is higher , with a higher proportion of senior professional titles and o-verseas study and work backgrounds .Through the establishment of multiple linear regression models for further study showed that the private hospital deans 'age , professional , technical titles and work experience has affected the com-petitiveness of the evaluation of the hospital .Therefore , this paper recommends that private hospitals should give full play to the advantages of expert dean and dean of the decision-making for core position should be clear , and the intro-duction and training of personnel presidency as a priority work .

Efficacy observation of botulinum toxin type A in elderly patients with primary intractable trigeminal neuralgia / 中华老年医学杂志

Objective To investigate the therapeutic effects of botulinum toxin type A (BTX-A) in elderly patients with primary intractable trigeminal neuralgia.Methods 27 elderly patients with primary intractable trigeminal neuralgia were treated with BTX-A local multiple point injection.The efficacy was assessed by visual analog scores (VAS) before and 1 week,2 weeks,1 month,3 months and 6 months after the treatment.Results VAS scores was (9.2±1.1),(5.8±3.0),(3.6± 2.3),(2.3±2.3),(3.2±2.9) and (4.6±3.2) before and 1 week,2 weeks,1 month,3 months and 6 months after BTX-A treatment respectively.VAS score was gradually decreased,reached the lowest at 1 month after BTX-A injection,and then was gradually increased.There were significant differences in VAS scores between between pre-and post-treatment (P＜0.05).The efficiency was 37.0％,85.2％,92.6％,70.4％ and 59.3％ at 1 week,2 weeks,1 month,3 months and 6 months after the treatment respectively.There were significant differences in efficacy between different time points after the treatment (all P＜0.05).3 patients had the transient numbness of mouth askew and incomplete eyelid closure and recovered spontaneously after 4-8 weeks.No severe adverse effects were found in the other 27 patients.Conclusions BTX-A is safe and effective in the treatment of primary intractable trigeminal neuralgia in elderly patients.

N-acetylcysteine protects bone marrow stromal cells against the toxicity of 6-hydroxydopamine / 中国组织工程研究

BACKGROUND: 6-hydroxydopamine, as an endogenous toxic factor in the pathogenesis of Parkinson's disease, participates in oxidative stress. N-acetylcysteine resists oxidation and removes free radicals effectively.OBJECTIVE: To investigate the toxicity of 6-hydroxydopamine in bone marrow stromal cells and the antagonistic effect of N-acetylcysteine on it. METHODS: Bone marrow stromal cells of Sprague-Dawley rats were cultured in vitro. Bone marrow stromal cells of passage 3 were treated with 6-hydroxydopamine with the final concentrations of 0,0.05,0.1g/L and N-acetylcysteine with the final concentrations of 0, 0.075,0.3,1.2,4.8g/L, respectively.RESULTS AND CONCLUSION: MTT assay showed that 6-hydroxydopamine (0.05 and 0.1 g/L) significantly decreased the viability of bone marrow stromal cells. This toxic effect of 6-hydroxydopamine was significantly inhibited by 0.3 g/L N-acetylcysteine. It suggests that antioxidant N-acetylcysteine may affect the toxic action of 6-hydroxydopamine.