DEEP inspiration breath-holds for breast cancer radiotherapy reduced cardiac radiation exposure, according to an exploratory study of 10 healthy female volunteers.
Researchers compared abdominal deep inspiration breath-hold and thoracic deep inspiration breath-hold during left-sided whole breast irradiation simulations.
Magnetic resonance imaging datasets were acquired in both prone and supine treatment positions during free breathing and each breath-hold technique.
The researchers assessed anatomical changes, spatial relationships between organs at risk and the irradiated breast, and planned radiation dose distributions.
Analysis showed that the heart shifted lower down in the body during abdominal deep inspiration breath-hold than during thoracic deep inspiration breath-hold.
In prone positioning, the additional inferior displacement measured 2.68 mm, while in supine positioning it measured 3.83 mm.
Distance volume histogram analysis also revealed slightly greater separation between the heart and irradiated breast during thoracic deep inspiration breath hold.
Mean differences in heart to breast distance favoured thoracic breathing by 0.19 cm in prone positioning and 0.21 cm in supine positioning.
Despite these anatomical differences, the magnitude of separation remained modest.
When radiotherapy plans were compared, no significant differences in heart dose were observed between abdominal and thoracic deep inspiration breath hold.
Mean heart dose values were similar across both approaches in prone and supine positions. Researchers also found no significant differences in ipsilateral lung dose between breathing techniques.
The only statistically significant dosimetric difference was a lower maximum dose to the contralateral breast during thoracic deep inspiration breath-hold in the prone position. The researchers considered this difference unlikely to be clinically relevant.
The study demonstrated that prone positioning consistently reduced radiation exposure to the ipsilateral lung and contralateral breast.
Deep inspiration breath-holds further improved cardiac sparing, particularly in the supine position.
The researchers concluded that although abdominal deep inspiration breath-hold produced greater inferior heart displacement, this did not translate into clinically meaningful improvements in cardiac or pulmonary dosimetry.
Their findings suggest that the use of deep inspiration breath-hold itself and patient positioning are more important determinants of heart and lung sparing than the choice between abdominal and thoracic breathing manoeuvres.
Reference
De Noyette R et al. Comparison of abdominal and thoracic deep inspiration breath holds on heart and lung radiation dose in breast cancer radiotherapy. Sci Rep. 2026;DOI:10.1038/s41598-026-65277-y
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