Minimizing preparation time for repeated prolonged deep-inspiration breath holds during breast cancer irradiation using pre-oxygenation with high flow nasal oxygen and voluntary hyperventilation.

Introduction: Deep inspiration breath-holds (DIBHs) reduce heart and lung toxicity during breast cancer radiotherapy. Consecutive DIBHs are stressful, time-consuming and leads to position changes. Pre-oxygenation using high flow nasal oxygen (HFNO) and hyperventilation prolongs DIBHs (L-DIBHs). We examined the effect of hyperventilation time on the duration of L-DIBHs. Additionally, to minimize total treatment time the feasibility of several successive L-DIBHs was examined.

Materials and methods: The method imposed 3 minutes of hyperventilation at 16 breaths per minute with preoxygenation using HFNO, in prone position. In the first phase, the effect of preparation time on the length of the breath-hold was investigated. The aim of the second phase was to investigate the feasibility of shorter preparation times before the second and third L-DIBH in the case of three consecutive L-DIBHs of 2 minutes.

Results: There is a positive but weak correlation between preparation time and L-DIBH duration. With either 3 min 30 second or 6 minutes 20 seconds (depending on fitness) of voluntary hyperventilation duration, 93% of subjects could hold three consecutive L-DIBHs for over 2 minutes. The median duration of the third and last L-DIBH was 3 min 17 s (SD 1 min 4 s).

Conclusion: A weak relationship exists between the hyperventilation time and L-DIBH duration. Repeating L-DIBHs with shorter preparations is achievable, resulting in a shorter total time required.

Advances in knowledge: It is possible to perform a repeated L-DIBH for breast cancer irradiation using HFNO.