Patterns and longitudinal changes in the practice of breast cancer radiotherapy in Korea: KROG 22-01
Hae Jin Park,
Korea Republic of
PO-1292
Abstract
Patterns and longitudinal changes in the practice of breast cancer radiotherapy in Korea: KROG 22-01
Authors: Hae Jin PARK1, Kyubo Kim2, Yong Bae Kim3, Jee Suk Chang3, Kyung Hwan Shin4
1Hanyang University College of Medicine, Radiation Oncology, Seoul, Korea Republic of; 2Ewha Womans University College of Medicine, Radiation Oncology, Seoul, Korea Republic of; 3Yonsei University College of Medicine, Radiation Oncology, Seoul, Korea Republic of; 4Seoul National University College of Medicine, Radiation Oncology, Seoul, Korea Republic of
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Purpose or Objective
To report contemporary practice patterns in breast cancer radiotherapy (RT) and to assess longitudinal changes in its use for five years in Korea
Material and Methods
A nationwide survey designed by the Division for Breast Cancer of the Korean Radiation Oncology Group circulated in March 2022 among all board-certified radiation oncologists in Korea. It consisted of 44 questions on six domains: hypofractionated (HypoFx) whole breast RT, accelerated partial breast RT (APBI), regional nodal irradiation (RNI), RT for ductal carcinoma in situ (DCIS), postmastectomy RT (PMRT), and tumor bed boost.
Results
Seventy radiation oncologists from 61 of 101 (60%) institutions answered this survey. Sixty-two respondents (89%) used HypoFx RT, dramatically increasing from 36% in 2017, and commonly adopted 40-42.5 Gy in 15-16 fractions. Twelve (17%) used APBI, which has increased from 5% in 2017. The general use of RNI has not changed much: ≥pN2 (6%), ≥pN1 (33%), and ≥pN1 with pathologic risk factors (61%). However, the indication for internal mammary lymph node (IMN) irradiation has widened: always treating IMN (11% from 6% in 2017) and treating when ≥pN2 (27% from 14 % in 2017) has doubled, but treating IMN only if IMN involvement identified on imaging has decreased to 31% from 47% in 2017. As for DCIS, the use of hypoFx RT has increased to 75% from 25%, and the consideration for omission of RT after breast-conserving surgery has decreased to 38% from 48% in 2017. The use of hypoFx RT for PMRT also has increased to 36% from 8% in 2017.
Conclusion
This survey shows high adoption of HypoFx RT after breast-conserving surgery in both invasive breast cancer and DCIS and moderate adoption of HypoFx RT for PMRT compared to 2017. Further studies to reach a consensus on applying RNI are advocated.