Association of sinoatrial node radiation dose with atrial fibrillation and mortality in lung cancer
Kyung Hwan Kim,
Korea Republic of
OC-0442
Abstract
Association of sinoatrial node radiation dose with atrial fibrillation and mortality in lung cancer
Authors: Kyung Hwan Kim1, Jaewon Oh2, Jee Suk Chang1, Hong In Yoon1
1Yonsei Cancer Center, Radiation Oncology, Seoul, Korea Republic of; 2Severance Cardiovascular Hospital and Cardiovascular Research Institute, Cardiology Division, Seoul, Korea Republic of
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Purpose or Objective
Radiotherapy-associated
cardiac toxicities in patients with small cell lung cancer (SCLC) has largely
been unexplored. The
purpose of this study was to describe the cardiac adverse events in SCLC and
determine predictive dosimetric parameters
Material and Methods
Between August 2008 and December 2019, 239 patients
with histologically confirmed limited-stage SCLCs treated with definitive chemoradiotherapy
were analyzed retrospectively. Dose-volume histograms of cardiac substructures
were calculated for each patient.
Results
At a median follow-up time of 26 months (IQR, 17–47
months), nine patients experienced new-onset atrial fibrillation (AF) and five
patients experienced non-AF cardiac events (acute coronary syndrome or heart
failure hospitalization). The maximum dose delivered to the sinoatrial node (SAN
Dmax) exhibited the highest predictive value for AF. The SAN Dmax≥53.5 Gy correlated with a
significantly higher 1-year cumulative incidence of AF compared with those that
received the SAN Dmax<53.5 Gy (13.9% vs. 1.0%; P < 0.001).
Adjusting for other clinical factors, the SAN Dmax≥53.5 Gy correlated with AF
(adjusted hazard ratio (aHR) 23.15; 95% CI, 4.91-109.2; P < 0.001) and
overall survival (aHR 2.68; 95% CI, 1.53-4.71; P < 0.001). The one-year
cumulative incidence of non-AF cardiac events was similar between SAN Dmax≥53.5 Gy and SAN Dmax<53.5.
Conclusion
Our results generated a strong hypothesis that high
doses irradiated to the SAN may facilitate the development of AF and increase
mortality, supporting the need to consider the radiation dose exposure to the SAN
during radiotherapy planning and close follow-up for the early detection of AF
in patients receiving thoracic irradiation.