Safely prolonging single breath-holds to >5 min in patients with cancer; feasibility and applications for radiotherapy

Abstract

Objective:Multiple, short and deep inspiratory breath-holds with air of approximately 20 s are now used in radiotherapy to reduce the influence of ventilatory motion and damage to healthy tissue. There may be further clinical advantages in delivering each treatment session in only one single, prolonged breath-hold. We have previously developed techniques enabling healthy subjects to breath-hold for 7 min. Here, we demonstrate their successful application in patients with cancer.Methods:15 patients aged 37–74 years undergoing radiotherapy for breast cancer were trained to breath-hold safely with pre-oxygenation and mechanically induced hypocapnia under simulated radiotherapy treatment conditions.Results:The mean breath-hold duration was 5.3 ± 0.2 min. At breakpoint, all patients were normocapnic and normoxic [mean end-tidal partial pressure of carbon dioxide was 36 ± 1 standard error millimetre of mercury, (mmHg) and mean oxygen saturation was 100 ± 0 standard error %]. None were distressed, nor had gasping, dizziness or disturbed breathing in the post-breath-hold period. Mean blood pressure had risen significantly from 125 ± 3 to 166 ± 4 mmHg at breakpoint (without heart rate falling), but normalized within approximately 20 s of the breakpoint. During breath-holding, the mean linear anteroposterior displacement slope of the L breast marker was <2 mm min−1.Conclusion:Patients with cancer can be trained to breath-hold safely and under simulated radiotherapy treatment conditions for longer than the typical beam-on time of a single fraction. We discuss the important applications of this technique for radiotherapy.Advances in knowledge:We demonstrate for the first time a technique enabling patients with cancer to deliver safely a single prolonged breath-hold of >5 min (10 times longer than currently used in radiotherapy practice), under simulated radiotherapy treatment conditions.

Abdominal organ motion during inhalation and exhalation breath-holds: pancreatic motion at different lung volumes compared

“…In addition, the observation that organ motion is more pronounced during the start of breathholding is also reflected in the data from earlier studies [18,24]. They reported a mean diaphragm [24]. So, delaying treatment for a certain amount of time after the start of breath-holding can result in a more stable anatomy.…”

“…at least 20-30 s). Breath-hold durations of >5 minutes have been shown to be feasible [24,30]. It may also be considered to use breath-holding in combination with a MR-guided linear accelerator system that can visualize tumor motion during irradiation [32,33].…”

Deep inspiration breath-hold radiotherapy for lung cancer: impact on image quality and registration uncertainty in cone beam CT image guidance

“…Our patients' DIBH durations were 20-30 s, only one patient performed a longer DIBH, therefore a 40-s DIBH acquisition may only be possible in very few selected patients, unless mechanical oxygen enhanced ventilation is applied. 25 Boda-Heggemann et al 15 reported on continuous acquisition of CBCT while the patient's respiration varied between DIBH and FB. They found the method produced a blurred tumour image with additional presence of a ghost tumour, representing the tumour's position in the FB.…”

Acceptance Testing and Quality Control of Digital Radiographic Imaging Systems

“…Another study using ABC was performed by Zhao et al (2008), with the results showing an average intra-fraction position of the diaphragm of 1.6 mm. Breath-hold treatments at full inspiration combined with breathing of oxygen can increase the fractional time that the beam is on, thereby increasing the delivery efficiency (Bush unpublished, 2003;Romano et al, 2013;Parkes et al, 2016) and, possibly, reducing intra-fraction motion.…”