» Articles » PMID: 39724924

Utilization and Regional Disparities of Radiotherapy in Cancer Treatment in Japan: a Longitudinal Study Using NDB Open Data

Overview
Authors
Affiliations
Soon will be listed here.
Abstract

The National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) is a database that stores anonymized information on medical receipts and health checkups in Japan. The NDB Open Data is a publicly accessible summary table of the NDB database. To reveal annual trends and regional disparities in radiotherapy utilization in Japan, we analyzed the NDB Open Data tables for a 9-year period from 2014 to 2022. We extracted medical cost codes for radiotherapy management fees and specific types of radiotherapy, such as stereotactic irradiation (STI) and intensity-modulated radiotherapy (IMRT), to analyze nationwide changes over time. To investigate regional disparities, we counted the three subitems representing 3-dimensional conformal radiotherapy (3D-CRT), IMRT, and STI for each prefecture per year. The utilization of advanced radiotherapy techniques, such as IMRT (199% increase), increased, while the use of simpler forms of irradiation, such as 1 or 2-opposite fields irradiation (40% decrease), decreased in the period from 2014 to 2022. Regarding regional disparities, the coefficients of variation in 47 prefectures for 3D-CRT remained relatively stable at 0.17 in 2014 and 0.18 in 2022, while the coefficients of variation for IMRT and STI decreased from 0.64 and 0.39 in 2014 to 0.31 and 0.36 in 2022, respectively. The popularization of IMRT was correlated with the number of certified radiation oncologists in the prefecture. In conclusion, although the utilization of high-precision radiotherapy in Japan has been increasing and regional differences have been diminishing, there are still persistent disparities.

References
1.
Howell D, James J, Hartsell W, Suntharalingam M, Machtay M, Suh J . Single-fraction radiotherapy versus multifraction radiotherapy for palliation of painful vertebral bone metastases-equivalent efficacy, less toxicity, more convenient: a subset analysis of Radiation Therapy Oncology Group trial 97-14. Cancer. 2012; 119(4):888-96. PMC: 5746185. DOI: 10.1002/cncr.27616. View

2.
Chan J, Polo A, Zubizarreta E, Bourque J, Hanna T, Gaudet M . Access to radiotherapy and its association with cancer outcomes in a high-income country: Addressing the inequity in Canada. Radiother Oncol. 2019; 141:48-55. DOI: 10.1016/j.radonc.2019.09.009. View

3.
Bryant A, Huynh-Le M, Simpson D, Mell L, Gupta S, Murphy J . Intensity Modulated Radiation Therapy Versus Conventional Radiation for Anal Cancer in the Veterans Affairs System. Int J Radiat Oncol Biol Phys. 2018; 102(1):109-115. DOI: 10.1016/j.ijrobp.2018.05.044. View

4.
Beckett M, Goethals L, Kraus R, Denysenko K, Barone Mussalem Gentiles M, Pynda Y . Proximity to Radiotherapy Center, Population, Average Income, and Health Insurance Status as Predictors of Cancer Mortality at the County Level in the United States. JCO Glob Oncol. 2023; 9:e2300130. PMC: 10581634. DOI: 10.1200/GO.23.00130. View

5.
Aoyama T, Koide Y, Shimizu H, Kitagawa T, Iwata T, Hashimoto S . Trends and distribution of external radiation therapy facilities in Japan based on Survey of Medical Institutions from the Ministry of Health, Labour and Welfare. J Radiat Res. 2024; 65(3):328-336. PMC: 11115472. DOI: 10.1093/jrr/rrae014. View