A JROD survey: nationwide overview of radiotherapy data from 2015 to 2021.

The purpose of this survey was to examine the status of radiotherapy in Japan based on the cases registered in the Japanese Radiation Oncology Database (JROD), from 2015 to 2021, and to provide basic data to help improve the usefulness of the JROD in the future. The study population consisted of patients who underwent radiotherapy between 2014 and 2020 and did not opt out of the study. The survey item data analyzed in this study were entered into the database at each radiotherapy institution by referring to medical records from the preceding year. Our results show that the number of registered radiotherapy institutions and cases increased by ~50% in 2019 compared to those in 2015 (to 113 institutions and 60 575 cases, respectively). Among the survey item categories, the registration rate was lowest for prognostic information (13.9% on average over the 7-year period). In terms of the Japanese Society for Radiation Oncology disease site, the breast; lung, trachea and mediastinum and urogenital sites accounted for >50% of the total cases. The average survival and mortality rates over the 7-year study period were 67.4 and 17.4%, respectively. The X-ray radiotherapy completion rate exceeded 90% for all years and across all disease categories. 192Ir-based brachytherapy and 223Ra-based radionuclide therapy accounted for an average of 61.9 and 44.6%, respectively, of all corresponding cases over the 7-year period. In conclusion, this survey enables us to infer the actual status of radiotherapy in Japan based on the analysis of relevant nationwide data.

A Japanese registry study and systematic review of particle therapy for renal cell carcinoma.

The feasibility and efficacy of particle beam therapy (PBT) using protons or carbon ions were compared with those of photon-based stereotactic body radiotherapy (SBRT) for primary renal cell carcinoma (RCC) via a systematic review and nationwide registry for PBT (Japanese Society for Radiation Oncology [JASTRO] particle therapy committee). Between July 2016 and May 2019, 20 patients with non-metastatic RCC who were treated at six Japanese institutes (using protons at three, using carbon ions at the other three) were registered in the nationwide database and followed up prospectively. The 20 patients comprised 15 men and had a median age of 67 (range: 57-88) years. The total radiation dose was 66-79.6 Gy (relative biological effectiveness [RBE]). Over a median follow up of 31 months, the 3-year rates of overall survival (OS) and local control (LC) were 100% and 94.4%, respectively. No grade ≥ 3 toxicities were observed. Based on a random effects model, a meta-analysis including the present results revealed 3-year OS rates after SBRT and PBT of 75.3% (95% CI: 57.3-86.6) and 94.3% (95% CI: 86.8-97.6), respectively (P = 0.005), but the difference in LC rates between the two methods was not observed (P = 0.63). PBT is expected to have similar if not better treatment results compared with SBRT for primary renal cancer. In particular, PBT was shown to be effective even for large RCC and could provide a therapeutic option when SBRT is not indicated.

Super-resolution generative adversarial networks with static T2*WI-based subject-specific learning to improve spatial difference sensitivity in fMRI activation.

The spatial resolution of fMRI is relatively poor and improvements are needed to indicate more specific locations for functional activities. Here, we propose a novel scheme, called Static T2*WI-based Subject-Specific Super Resolution fMRI (STSS-SRfMRI), to enhance the functional resolution, or ability to discriminate spatially adjacent but functionally different responses, of fMRI. The scheme is based on super-resolution generative adversarial networks (SRGAN) that utilize a T2*-weighted image (T2*WI) dataset as a training reference. The efficacy of the scheme was evaluated through comparison with the activation maps obtained from the raw unpreprocessed functional data (raw fMRI). MRI images were acquired from 30 healthy volunteers using a 3 Tesla scanner. The modified SRGAN reconstructs a high-resolution image series from the original low-resolution fMRI data. For quantitative comparison, several metrics were calculated for both the STSS-SRfMRI and the raw fMRI activation maps. The ability to distinguish between two different finger-tapping tasks was significantly higher [p = 0.00466] for the reconstructed STSS-SRfMRI images than for the raw fMRI images. The results indicate that the functional resolution of the STSS-SRfMRI scheme is superior, which suggests that the scheme is a potential solution to realizing higher functional resolution in fMRI images obtained using 3T MRI.

Japanese structure survey of radiation oncology in 2015.

This article describes the ongoing structure of radiation oncology in Japan in terms of equipment, personnel, patient load and geographic distribution to identify and overcome any existing limitations. From May 2016 to August 2018, the Japanese Society for Radiation Oncology conducted a questionnaire based on the Japanese national structure survey of radiation oncology in 2015. Data were analyzed based on the institutional stratification by the annual number of new patients treated with radiotherapy per institution. The estimated annual numbers of new and total (new plus repeat) patients treated with radiation were 225 000 and 271 000, respectively. Additionally, the estimated cancer incidence was 891 445 cases with approximately 25.2% of all newly diagnosed patients being treated with radiation. The types and numbers of treatment devices actually used included linear accelerator (linac; n = 936), Gamma Knife (n = 43), 60Co remote afterloading system (RALS; n = 21), and 192Ir RALS (n = 129). The linac system used dual-energy functions in 754 units, 3D conformal radiotherapy functions in 867, and intensity-modulated radiotherapy (IMRT) functions in 628. There were 899 Japan Radiological Society/Japanese Society for Radiation Oncology-certified radiation oncologists (RO), 1213.9 full-time equivalent (FTE) ROs, 2394.2 FTE radiotherapy technologists (RTT), 295.7 FTE medical physicists, 210.2 FTE radiotherapy quality managers, and 906.1 FTE nurses. The frequency of IMRT use significantly increased during this time. In conclusion, the Japanese structure of radiation oncology has clearly improved in terms of equipment and utility although there was a shortage of personnel in 2015.

Forecasting the regional distribution and sufficiency of physicians in Japan with a coupled system dynamics-geographic information system model.

BACKGROUND: In Japan, the shortage of physicians has been recognized as a major medical issue. In our previous study, we reported that the absolute shortage will be resolved in the long term, but maldistribution among specialties will persist. To address regional shortage, several Japanese medical schools increased existing quota and established "regional quotas." This study aims to assist policy makers in designing effective policies; we built a model for forecasting physician numbers by region to evaluate future physician supply-demand balances. METHODS: For our case study, we selected Hokkaido Prefecture in Japan, a region displaying disparities in healthcare services availability between urban and rural areas. We combined a system dynamics (SD) model with geographic information system (GIS) technology to analyze the dynamic change in spatial distribution of indicators. For Hokkaido overall and for each secondary medical service area (SMSA) within the prefecture, we analyzed the total number of practicing physicians. For evaluating absolute shortage and maldistribution, we calculated sufficiency levels and Gini coefficient. Our study covered the period 2010-2030 in 5-year increments. RESULTS: According to our forecast, physician shortage in Hokkaido Prefecture will largely be resolved by 2020. Based on current policies, we forecast that four SMSAs in Hokkaido will continue to experience physician shortages past that date, but only one SMSA would still be understaffed in 2030. CONCLUSION: The results show the possibility that diminishing imbalances between SMSAs would not necessarily mean that regional maldistribution would be eliminated, as seen from the sufficiency levels of the various SMSAs. Urgent steps should be taken to place doctors in areas where our forecasting model predicts that physician shortages could occur in the future.

Patient Accessibility to Hospitals in Winter Road Conditions: GIS-Based Analysis Using Car Navigation Probe Data.

The purpose of this study was to estimate geographical patient flow to hospitals during winter seasons using simulation analysis. We used probe data collected from car navigation systems and performed a Geographical Information System (GIS)-based analysis to determine the relationship between travel time to hospitals and winter road conditions. Accessibility to hospitals based on travel time in summer and winter was overlayed on a map to demonstrate the increase in travel time during winter.

Trends for the Geographic Distribution of Radiological Resources in Hokkaido, Japan: Data Analysis Using Gini Coefficient and Herfindahl-Hirschman Index.

The aim of this study is to analyze the maldistribution and the trends in the geographic distribution of radiological resources in secondary medical areas of Hokkaido. The distribution was measured by combining the Gini coefficient (GC), which is an indicator of inequality of distribution, and the Herfindahl-Hirschman index (HHI), which is mainly used to assess market concentration. Data concerning the distribution of radiological resources, such as CT, MRI, radiotherapy facilities (RTF), radiological technologists (RT), and medical doctors were obtained from official publications. CT was more equally distributed, and RTF was more inequality than other radiological resources in 2014. Radiological resources excluded CT were higher degree of concentration than population distribution, and it showed that they were located relatively more intensively in urban areas than in rural areas. During the period 1999-2014, the GC for CT, MRI, RTF, and RT decreased, while the HHI increased. These trends indicated increased equality of distribution of CT, MRI, RTF, and RT and the concentration in urban areas. This study suggested that GC and HHI could be powerful indicators for allocation planning of medical resources with further analysis of the maldistribution of medical resources.

Forecasting the absolute and relative shortage of physicians in Japan using a system dynamics model approach.

BACKGROUND: In Japan, a shortage of physicians, who serve a key role in healthcare provision, has been pointed out as a major medical issue. The healthcare workforce policy planner should consider future dynamic changes in physician numbers. The purpose of this study was to propose a physician supply forecasting methodology by applying system dynamics modeling to estimate future absolute and relative numbers of physicians. METHOD: We constructed a forecasting model using a system dynamics approach. Forecasting the number of physician was performed for all clinical physician and OB/GYN specialists. Moreover, we conducted evaluation of sufficiency for the number of physicians and sensitivity analysis. RESULT & CONCLUSION: As a result, it was forecast that the number of physicians would increase during 2008-2030 and the shortage would resolve at 2026 for all clinical physicians. However, the shortage would not resolve for the period covered. This suggests a need for measures for reconsidering the allocation system of new entry physicians to resolve maldistribution between medical departments, in addition, for increasing the overall number of clinical physicians.

Geographical distribution of radiotherapy resources in Japan: investigating the inequitable distribution of human resources by using the Gini coefficient.

This is a pilot study that aims to elucidate regional disparities in the distribution of medical resources in Japan. For this purpose, we employed the Gini coefficient (GC) in order to analyze the distribution of radiotherapy resources, which are allocated to each prefecture in Japan depending on the size of its population or physical area. Our study used data obtained from the 2005 and 2007 national surveys on the structure of radiation oncology in Japan, conducted by the Japanese Society for Therapeutic Radiology and Oncology (JASTRO). Our analysis showed that the regional disparities regarding the radiation oncologists and radiotherapy technologists were small, and concluded that such resources were almost equitably distributed. However, medical physicists are inequitably distributed. Thus, policymakers should create and implement measures to train and retain medical physicists in areas with limited radiotherapy resources. Further, almost 26% of the secondary medical service areas lacked radiotherapy institutions. We attribute this observation to the existence of tertiary medical service areas, and almost all of prefectures face a shortage of such resources. Therefore, patients' accessibility to these resources in such areas should be improved.

Development of terminology for mammographic techniques for radiological technologists.

We are developing a mammographic ontology to share knowledge of the mammographic domain for radiologic technologists, with the aim of improving mammographic techniques. As a first step in constructing the ontology, we used mammography reference books to establish mammographic terminology for identifying currently available knowledge. This study proceeded in three steps: (1) determination of the domain and scope of the terminology, (2) lexical extraction, and (3) construction of hierarchical structures. We extracted terms mainly from three reference books and constructed the hierarchical structures manually. We compared features of the terms extracted from the three reference books. We constructed a terminology consisting of 440 subclasses grouped into 19 top-level classes: anatomic entity, image quality factor, findings, material, risk, breast, histological classification of breast tumors, role, foreign body, mammographic technique, physics, purpose of mammography examination, explanation of mammography examination, image development, abbreviation, quality control, equipment, interpretation, and evaluation of clinical imaging. The number of terms that occurred in the subclasses varied depending on which reference book was used. We developed a terminology of mammographic techniques for radiologic technologists consisting of 440 terms.

[A survey of medical information education in radiological technology schools].

The purpose of this study was to clarify actual conditions and problems in medical information education and to propose the educational concept to be adopted in medical information. A questionnaire survey was carried out by the anonymous method in June 2008. The survey was intended for 40 radiological technology schools. The questionnaire items were as follows: (1) educational environment in medical information education, (2) content of a lecture in medical information, (3) problems in medical information education. The response rate was 55.0% (22 schools). Half of the responding schools had a laboratory on medical information. Seventeen schools had a medical information education facility, and out of them, approximately 50% had an educational medical information system. The main problems of the medical information education were as follows: (a) motivation of the students is low, (b) the educational coverage and level for medical information are uncertain, (c) there are not an appropriate textbook and educational guidance. In conclusion, these findings suggest that it is necessary to have a vision of medical information education in the education of radiological technologists.

Measuring the inequalities in radiotherapy health resources in Japan: comparison of the Hokkaido-Tohoku and Tokyo districts.

PURPOSE: The aim of this study was to measure and compare the geographical inequalities in radiotherapy health resources between the Hokkaido-Tohoku and Tokyo districts of Japan. MATERIALS AND METHODS: The numbers of radiotherapy facilities, radiologists, and radiological technologists were used to represent radiotherapy health resources. The target areas were 11 prefectures in the Hokkaido-Tohoku and Tokyo districts. The Gini coefficient (GC) was used to measure inequalities in health resources in relation to the population and area of each secondary medical care zone. Correlation analysis was performed to clarify the relation between the GC and the all-cancer mortality rate per 100,000 people. RESULTS: The mean population and area GCs of Yamagata Prefecture were the smallest, whereas the mean population GC of Tokyo and the mean area GC of Hokkaido were the largest. The mean GCs of radiotherapy facilities and radiological technologists were higher in the Tokyo district than in the Hokkaido-Tohoku district. No significant correlation was found between GC and cancer mortality. CONCLUSION: Geographical inequalities in radiotherapy health resources tended to be larger in the Tokyo district than in the Hokkaido-Tohoku district. It is expected that the radiotherapy system will be substantially improved by the Basic Plan to Promote Cancer Control Programs.

[A survey of information literacy for undergraduate students in the department of radiological technology].

The purpose of this study was to clarify the information literacy of undergraduate students and problems in information education. An annual questionnaire survey was carried out by an anonymous method from 2003 to 2006. The survey was intended for third-year students in the Department of Radiological Technology. The questionnaire items were as follows: (1) ownership of a personal computer (PC), (2) usage purpose and frequency of PC operation, (3) operation frequency and mechanism of the Internet, and (4) IT terminology. The response rate was 100% in each year. The ratio of PC possession exceeded 80%. The ratio of students who replied "nearly every day" for the use of a PC and the Internet increased twofold and threefold in four years, respectively. More than 70% of students did not understand the mechanism of the Internet, and more than 60% of students did not know about TCP/IP. In the future, we need to consider information literacy education in undergraduate education.

[Research on the shielding evaluation method for medical X-ray imaging facilities].

The purpose of this study was to verify the shielding evaluation method for medical X-ray imaging facilities in Report No. 147 of the National Council on Radiation Protection and Measurements (NCRP). We investigated the concept of radiation protection and the major revised point in Report No. 147. The goal of radiation protection in Report No. 147 was compared with that in Japan. Using the data of the Imaging Performance Assessment of CT scanners (ImPACT) 2006 and the latest pre-installation manuals of several manufactures for different computed tomography (CT) scanner models, we verified the shielding method for CT installations. The concept of radiation protection in Report No. 147 was based on the recommendation of the International Commission on Radiological Protection (ICRP) Publication 60. On the shielding method for CT units, compared with the CT scatter fraction for the body phantom in Report No. 147 was approximately 10% less than the results of the computation. In conclusion, we should note the use of the CT scatter fraction for the body phantom provided by Report No. 147; however, it is possible to apply the fundamental concept of the shielding evaluation in Report No. 147 to the shielding evaluation method in Japan.

Maternal and neonatal factors associated with the high yield of mononuclear low-density/CD34+ cells from placental/umbilical cord blood.

Placental/umbilical cord blood (CB) contains nucleated cells and hematopoietic stem/progenitor cells (CD34(+) cells). However it is difficult to predict the number of nucleated/CD34(+) cells in each CB before cell processing. Despite many previous studies from institutes affiliated with CB banks in metropolitan areas, little information is available regarding the characteristics of CB units from other medical facilities. The purpose of the present study was to analyze the maternal/neonatal factors on the yield of cells in CB units. A total of 176 CB units were obtained from single-birth and normal vaginal deliveries. Mononuclear low-density (LD) cells were separated using Ficoll-Paque within 24 hrs after CB collection and then processed for the purification of CD34(+) cells. A multiple linear regression analysis was performed to assess the correlations between the yield of cells and maternal/neonatal factors including maternal age, gravid status, duration of labor, gestational age, neonatal height and weight, cord length, and meconium in the amniotic fluid. The total LD cells per CB unit had a weak positive correlation with the maternal age of primigravidae. The total LD cells per CB unit from the primigravidae aged > or = 25 were significantly higher than those from the primigravidae aged < or = 24. The total CD34(+) cells per CB unit from the 1-gravidae were significantly higher than those from the 2-gravidae and 3-gravidae, respectively among all donors. These results indicate that the CB units from the primigravidae aged > or = 25 are more likely to contain higher yield of LD/CD34(+) cells.

[Survey and analysis of radiation safety management systems at medical institutions--second report: radiation measurement, calibration of radiation survey meters, and periodic check of installations, equipment, and protection instruments].

We carried out a questionnaire survey to determine the actual situation of radiation safety management measures in all medical institutions in Japan that had nuclear medicine facilities. The questionnaire consisted of questions concerning the evaluation of shielding capacity; radiation measurement; periodic checks of installations, equipment, and protection instruments; and the calibration of radiation survey meters. The analysis was undertaken according to region, type of establishment, and number of beds. The overall response rate was 60 percent. For the evaluation of shielding capacity, the outsourcing rate was 53 percent of the total. For the radiation measurements of "leakage radiation dose and radioactive contamination" and "contamination of radioactive substances in the air," the outsourcing rates were 28 percent and 35 percent of the total, respectively (p<0.001, according to region and establishment). For the periodic check of radiation protection instruments, the implementation rate was 98 percent, and the outsourcing rate was 32 percent for radiation survey meters and 47 percent for lead aprons. The non-implemented rate for calibration of radiation survey meters was 25 percent of the total (p<0.001, according to region and establishment). The outsourcing rate for calibration of radiation survey meters accounted for 87 percent of the total, and of these medical institutions, 72 percent undertook annual calibration. The implementation rate for patient exposure measurement was 20 percent of the total (p<0.001, according to number of beds), and of these medical institutions 46 percent recorded measurement outcome.

Model analysis for optimal allocation of pediatric emergency center.

Optimal allocation of Pediatric Emergency Centers was simulated using both Min-Sum model and Min-Max model, based on the travel distance and child population of Hokkaido prefecture, Japan. Our result should be helpful to select the optimal number and allocation of PECs in the actual scene of decision making, where the financial restriction exists.