The purpose of the study was to compare a 3D convolutional neural network (CNN) with the conventional machine learning method for predicting intensity-modulated radiation therapy (IMRT) dose distribution using only contours in prostate cancer. In this study, which included 95 IMRT-treated prostate cancer patients with available dose distributions and contours for planning target volume (PTVs) and organs at risk (OARs), a supervised-learning approach was used for training, where the dose for a voxel set in the dataset was defined as the label. The adaptive moment estimation algorithm was employed for optimizing a 3D U-net similar network. Eighty cases were used for the training and validation set in 5-fold cross-validation, and the remaining 15 cases were used as the test set. The predicted dose distributions were compared with the clinical dose distributions, and the model performance was evaluated by comparison with RapidPlan™. Dose–volume histogram (DVH) parameters were calculated for each contour as evaluation indexes. The mean absolute errors (MAE) with one standard deviation (1SD) between the clinical and CNN-predicted doses were 1.10% ± 0.64%, 2.50% ± 1.17%, 2.04% ± 1.40%, and 2.08% ± 1.99% for D2, D98 in PTV-1 and V65 in rectum and V65 in bladder, respectively, whereas the MAEs with 1SD between the clinical and the RapidPlan™-generated doses were 1.01% ± 0.66%, 2.15% ± 1.25%, 5.34% ± 2.13% and 3.04% ± 1.79%, respectively. Our CNN model could predict dose distributions that were superior or comparable with that generated by RapidPlan™, suggesting the potential of CNN in dose distribution prediction.

Background Few studies exploring the actual practices implemented for long-term mental health and psychosocial support after a natural disaster have been published. This study aimed to reveal (1) the types of activities that were actually provided as mental health and psychosocial support (MHPSS) in the long-term phase after the Great East Japan Earthquake (GEJE) and (2) the problems that must be addressed to provide post-disaster MHPSS activities. Methods An open-ended questionnaire was sent to organizations in the Iwate, Miyagi and Fukushima prefectures that were potentially involved in providing MHPSS to communities affected by the GEJE. The organizations were asked to describe their activities and the problems that needed to be addressed to provide these support activities. The collected statements were analysed using content analysis with NVivo11. Results The support activities conducted to provide MHPSS in the long-term phase after the catastrophe were diverse and classified into 7 major categories, namely, (1) one-on-one support for individuals in need of assistance, (2) support for collective activities, (3) support around living conditions and income, (4) increasing public awareness about mental health, (5) human resource development to improve response capabilities for MHPSS, (6) support for MHPSS providers, and (7) facilitating collaborations among the MHPSS activities provided to affected communities. Problems with human resources and funding were the most frequently mentioned concerns among the organizations participating in the survey. Conclusions The establishment of systems to collect and share sufficient and relevant knowledge and to coordinate organizations for long-term post-disaster postventions would be desirable. Electronic supplementary material The online version of this article (10.1186/s12888-019-2243-z) contains supplementary material, which is available to authorized users.

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Carbon addition to electrodeposited Co-Mo alloys was made to enhance electrolytic hydrogen evolution activity and to prevent open-circuit corrosion in 8 M NaOH at 90°C. Co-30 atom % Mo alloy showed the highest activity for hydrogen evolution among the binary Co-Mo alloys, but open-circuit immersion resulted in dissolution of molybdenum as molybdate, with a consequent decrease in the hydrogen evolution activity. Addition of carbon to electrodeposited Co-Mo alloys by adding lysine in the deposition electrolytes further enhanced hydrogen evolution activity and slowed dissolution of molybdenum during open-circuit immersion, although complete prevention of dissolution of molybdenum was not attained.