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.

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.

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.

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.

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.

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.

[Survey and analysis of radiation safety management systems at medical institutions--initial report: radiation protection supervisor, radiation safety organization, and education and training].

In this study, a questionnaire survey was carried out to determine the actual situation of radiation safety management systems in Japanese medical institutions with nuclear medicine facilities. The questionnaire consisted of questions concerning the Radiation Protection Supervisor license, safety management organizations, and problems related to education and training in safety management. Analysis was conducted according to region, type of establishment, and number of beds. The overall response rate was 60%, and no significant difference in response rate was found among regions. Medical institutions that performed nuclear medicine practices without a radiologist participating accounted for 10% of the total. Medical institutions where nurses gave patients intravenous injections of radiopharmaceuticals as part of the nuclear medicine practices accounted for 28% of the total. Of these medical institutions, 59% provided education and training in safety management for nurses. The rate of acquisition of Radiation Protection Supervisor licenses was approximately 70% for radiological technologists and approximately 20% for physicians (regional difference, p=0.02). The rate of medical institutions with safety management organizations was 71% of the total. Among the medical institutions (n=208) without safety management organizations, approximately 56% had 300 beds or fewer. In addition, it became clear that 35% of quasi-public organizations and 44% of private organizations did not provide education and training in safety management (p<0.001, according to establishment).

[Survey and analysis of radiation safety education at radiological technology schools].

We carried out a questionnaire survey of all radiological technology schools, to investigate the status of radiation safety education. The questionnaire consisted of questions concerning full-time teachers, measures being taken for the Radiation Protection Supervisor Qualifying Examination, equipment available for radiation safety education, radiation safety education for other departments, curriculum of radiation safety education, and related problems. The returned questionnaires were analyzed according to different groups categorized by form of education and type of establishment. The overall response rate was 55%, and there were statistically significant differences in the response rates among the different forms of education. No statistically significant differences were found in the items relating to full-time teachers, measures for Radiation Protection Supervisor Qualifying Examination, and radiation safety education for other departments, either for the form of education or type of establishment. Queries on the equipment used for radiation safety education revealed a statistically significant difference in unsealed radioisotope institutes among the forms of education. In terms of curriculum, the percentage of radiological technology schools which dealt with neither the shielding calculation method for radiation facilities nor with the control of medical waste was found to be approximately 10%. Other educational problems that were indicated included shortages of full-time teachers and equipment for radiation safety education. In the future, in order to improve radiation safety education at radiological technology schools, we consider it necessary to develop unsealed radioisotope institutes, to appoint more full-time teachers, and to educate students about risk communication.