ESTRO 2025 - Abstract Book

S1455

Clinical – Mixed sites & palliation

ESTRO 2025

32

Digital Poster A nationwide claim database study of single-fraction palliative radiotherapy in Japan Yutaro Koide, Takahiro Aoyama, Masamune Noguchi, Yurika Shindo, Tomoki Kitagawa, Hidetoshi Shimizu, Shingo Hashimoto, Hiroyuki Tachibana, Takeshi Kodaira Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Japan Purpose/Objective: This study aimed to evaluate recent trends in single-fraction conventional palliative radiotherapy (CRT) in Japan, including during the COVID-19 pandemic, using data from the National Database published by the Ministry of Health, Labour, and Welfare [1]. Material/Methods: We analyzed data from FY2014 to FY2022. The practices included in the survey were single-fraction CRT. Multi fraction CRT, stereotactic body radiotherapy (SBRT), intensity-modulated radiotherapy (IMRT), and brachytherapy were excluded from the analysis. The primary outcome was the single-fraction CRT rate in palliative radiotherapy for bone metastases, estimated using NDB and the structural survey by the Japanese Society for Radiation Oncology [1 – 4]. For the COVID-19 epidemic period (FY2020 – FY2021), available monthly data were evaluated and compared to average linear estimates from FY2019 to FY2022. Results: We identified 33,221 single-fraction CRT courses from 2,315,607 overall radiotherapies, excluding courses in multi fraction CRT (n = 1,835,650), SBRT (n = 33,935), IMRT (n = 332,827), and brachytherapy (n = 113,195). The annual single-fraction CRT courses gradually increased from 1,730 (FY2014) to 5,642 (FY2022), with an average increase ratio of 0.28 (range: -0.07 – 0.65) by year, corresponding to 6.1% (FY2014) to 15.2% (FY2022) of estimated palliative bone radiotherapy courses in the same years. Compared between inpatient and outpatient courses, outpatient courses have rapidly increased in recent years, especially in high amounts since FY2019, overcoming inpatient courses in FY2022 (2,728 vs. 2,914). In FY2020, the average annual increase was the highest in previous years, especially in the first half of the year (April to August), but this increasing trend did not continue in FY2021. Conclusion: Single-fraction CRT showed a continuous increase to 15.2 % of palliative bone radiotherapy in Japan, suggesting an increasing role in palliative radiotherapy. The temporary increase boost caused by the COVID-19 pandemic has already ended its impact and is converging to the pre-pandemic increase rate. References: [1] Ministry of Health, Labour and Welfare. The National Health Insurance Claims and Specific Health Examination Database. available at https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/0000177182.html (Accessed on August 1, 2024). [2] Japanese Structure Survey of Radiation Oncology in 2015 available at https://www.jastro.or.jp/medicalpersonnel/data_center/cat6/ (Accessed on June 10, 2023) [3] Japanese Structure Survey of Radiation Oncology in 2017 available at https://www.jastro.or.jp/medicalpersonnel/data_center/cat6/ (Accessed on June 10, 2023). [4] Japanese Structure Survey of Radiation Oncology in 2019 available at https://www.jastro.or.jp/medicalpersonnel/data_center/cat6/ (Accessed on June 10, 2023). Keywords: Palliative radiotherapy, bone metastases, COVID-19