Clinical factors affecting breath-hold performance for left-sided breast cancer patients

Deep inspiration breath hold (DIBH) is a treatment technique used for patients with left-sided breast cancer to move the heart further from the treatment area and thus reduce cardiac toxicity. Active participation of the patient plays a vital role in the success and efficiency of DIBH. The purpose of this study was to investigate various clinical factors that can influence breath-hold performance.

Surface-guided radiotherapy (SGRT) data from 72 left-sided DIBH breast cancer patients monitored with AlignRT (VisionRT) were retrospectively analyzed to evaluate breath-hold accuracy (deviation of patient surface at treatment from the CT simulation surface), reproducibility, and the percentage of breath holds within tolerance (%WT). An internal Python-based tool was developed to identify all breath holds from acquired breathing traces during patient setup and treatment. Patients were grouped based on clinical factors such as age, English proficiency, and reported pain or anxiety. Group differences in the breath-hold performance metrics were assessed using the Mann-Whitney U test.

Breath-hold accuracy did not show statistically significant differences across any patient groups. However, reproducibility was significantly worse for patients reporting pain (standard deviation = 2.54 mm vs. 1.69 mm, p = 0.0003), indicating greater difficulty in maintaining consistent breath-hold levels. In terms of %WT, patients with reported anxiety demonstrated lower performance (83.3% vs. 90.2%, p = 0.03), as did patients reporting pain (80.6% vs. 86.9%, p = 0.02). These findings suggest that both pain and anxiety are factors that may negatively impact a patient's ability to consistently hold their breath during treatment.

This study highlights the importance of addressing patient-reported pain and anxiety in achieving optimal breath-hold performance during DIBH treatments. While factors such as age and English proficiency did not significantly impact breath-hold metrics, pain and anxiety were associated with impaired reproducibility and reduced time within tolerance. These results suggest that targeted interventions, such as pain management strategies, additional coaching, or supportive devices to increase patient comfort, may improve patient outcomes and clinical efficiency for anxious patients or those in pain. DIBH remains a feasible and effective technique for patients regardless of age or native language in the patient cohort we investigated.