Stability and reproducibility of 6013 deep inspiration breath-holds in left-sided breast cancer

Reitz, Daniel; Walter, Franziska; Schönecker, S.; Freislederer, Philipp; Pazos, M.; Niyazi, Maximilian; Landry, Guillaume ; Alongi, F.; Bölke, E.; Matuschek, C.; Reiner, Michael; Belka, Claus und Corradini, Stefanie (2020): Stability and reproducibility of 6013 deep inspiration breath-holds in left-sided breast cancer. In: Radiation Oncology, Bd. 15, Nr. 1, 121

Abstract

Purpose: Patients with left-sided breast cancer frequently receive deep inspiration breath-hold (DIBH) radiotherapy to reduce the risk of cardiac side effects. The aim of the present study was to analyze intra-breath-hold stability and inter-fraction breath-hold reproducibility in clinical practice.

Material and methods: Overall, we analyzed 103 patients receiving left-sided breast cancer radiotherapy using a surface-guided DIBH technique. During each treatment session the vertical motion of the patient was continuously measured by a surface guided radiation therapy (SGRT) system and automated gating control (beam on/off) was performed using an audio-visual patient feedback system. Dose delivery was automatically triggered when the tracking point was within a predefined gating window. Intra-breath-hold stability and inter-fraction reproducibility across all fractions of the entire treatment course were analyzed per patient.

Results: In the present series, 6013 breath-holds during beam-on time were analyzed. The mean amplitude of the gating window from the baseline breathing curve (maximum expiration during free breathing) was 15.8 mm (95%-confidence interval: [8.5–30.6] mm) and had a width of 3.5 mm (95%-CI: [2–4.3] mm). As a measure of intra-breath-hold stability, the median standard deviation of the breath-hold level during DIBH was 0.3 mm (95%-CI: [0.1–0.9] mm). Similarly, the median absolute intra-breath-hold linear amplitude deviation was 0.4 mm (95%-CI: [0.01–2.1] mm). Reproducibility testing showed good inter-fractional reliability, as the maximum difference in the breathing amplitudes in all patients and all fractions were 1.3 mm on average (95%-CI: [0.5–2.6] mm).

Conclusion: The clinical integration of an optical surface scanner enables a stable and reliable DIBH treatment delivery during SGRT for left-sided breast cancer in clinical routine.

• Dokumententyp: Zeitschriftenartikel
• Keywords: Surface guided radiation therapy; Breast cancer; DIBH; Intra-breath-hold; Inter-fraction; Stability; Reproducibility; Optical surface scanner
• Fakultät: Medizin ; Physik
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• Sprache: Englisch