Current situation and trends of radiation therapy in Japan based on the National Database Open Data

Abstract

This study aimed to visualize the current situation and trends in radiation therapy in Japan using open data from the Japanese National Database of Health Insurance Claims and Specific Health Checkups (NDB). We downloaded the NDB open data from the website of Japan's Ministry of Health, Labor and Welfare and used Python libraries to analyze the receipt data related to radiation therapy from fiscal year 2014 to 2022. The number of radiation therapy plans peaked in 2019, temporarily declined and subsequently showed a gradual increase. Conversely, the total points associated with radiation therapy have consistently increased without any decline. The use of high-precision radiation therapies such as intensity-modulated radiation therapy (IMRT) has increased over time. Significant regional differences exist, with the Chubu and Kyushu regions showing higher total points and receipts per certified radiation oncologist. A correlation was observed between the number of IMRT plans per population and the number of certified radiation oncologists. Males exhibited a sharp peak in their early 70s, while females demonstrated a mild peak from their 40s to 80s. In recent years, the points for males in their early 70s have rapidly increased. We used the NDB open data to illustrate the current situation and trends in radiation therapy in Japan, highlighting reduced costs and workloads. This study underscored the regional differences in radiation therapy and emphasized the need to discuss strategies for meeting future demand.

Keywords: intensity-modulated radiation therapy; national database; open data; radiation therapy.

Fig. 1

(A) Annual changes in total points for radiation therapy by classification codes. The total points have increased over the years, with a rise in the codes M001, M001–3, M001–4 and additions. (B) Annual changes and distribution of the number of receipts for M000, M001–2, M001–3 and M001–4. The number of receipts temporarily decreased in FY 2020, but eventually increased. Although the use of two-port irradiation has a decreasing trend, the use of irradiation with four or more ports, IMRT, SRT and PBT has shown an increasing trend. Abbreviations: RT = radiation therapy, SRS = sealed radioactive sources, BT = brachytherapy, IMRT = intensity-modulated radiation therapy, SRT = stereotactic radiation therapy.

Fig. 2

The line graph illustrates the annual changes in the number of treatments based on the JASTRO structural survey. The number of radiation therapy patients has been declining since 2019, when it reached its highest. IMRT shows a rising trend. Only the 2017 and 2019 surveys reported the number of particle beam therapy. Abbreviations: BT = brachytherapy, RAI = radioactive iodine therapy, TBI = total body irradiation, SRT = stereotactic radiation therapy, SBRT = stereotactic body radiation therapy, IMRT = intensity-modulated radiation therapy.

Fig. 3

(A) Distribution of total points for radiation therapy in different prefectures. (B) Distribution of the number of receipts for M000, M001–2, M001–3 and M001–4 in different prefectures. Both panels show higher numbers in the urban prefectures, including Tokyo.

Fig. 4

(A) Distribution of total points for radiation therapy for every enrolled certificated radiation oncologist in each prefecture. (B) Distribution of the number of receipts for M000, M001–2, M001–3 and M001–4 for every enrolled certificated radiation oncologist in each prefecture. Both panels show higher numbers in the Chubu and Kyushu regions, while the numbers were lower in Tokyo.

Fig. 5

(A) A scatter plot showing the relationship between population and radiation therapy points in each prefecture. The plot size reflects the number of certificated radiation oncologists in a specific prefecture. (B) Scatter plot showing the relationship between population and IMRT management fee receipts in each prefecture. The number of IMRT plans was lower in prefectures with fewer certificated radiation oncologists than in prefectures with similar population sizes.

Fig. 6

The points for radiation therapy are distributed differently by patients’ sex and age. Males showed a significant peak in their 70s, while females showed a mild peak from 40 to 80 years old. In both sexes, M001 accounts for the majority of points in every age group.