Voluntary versus ABC breath-hold in the context of VMAT for breast and locoregional lymph node radiotherapy including the internal mammary chain.
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Embargo End Date
ICR Authors
Authors
Ranger, A
Dunlop, A
Grimwood, A
Durie, E
Donovan, E
Havilland, J
Harris, E
McNair, H
Kirby, AM
Dunlop, A
Grimwood, A
Durie, E
Donovan, E
Havilland, J
Harris, E
McNair, H
Kirby, AM
Document Type
Journal Article
Date
2021-02-23
Date Accepted
2021-02-07
Abstract
BACKGROUND: Deep-inspiration breath-hold (DIBH) reduces radiation dose to the heart in patients undergoing locoregional breast radiotherapy. In the context of tangential irradiation of the breast/ chest wall, a voluntary breath hold (vDIBH) technique has been shown to be as reproducible as a machine-assisted breath hold technique using the active breathing co-ordinator (ABC™, Elekta, Crawley, UK, ABC_DIBH). This study compares set-up reproducibility for vDIBH versus ABC_DIBH in patients undergoing volumetric-modulated arc radiotherapy (VMAT) for breast cancer, both with and without wax bolus. METHOD: Patients with breast cancer requiring pan regional lymph node VMAT +/- wax bolus in breath-hold were CT scanned in vDIBH and ABC_DIBH. Patients were randomised to receive one technique for fractions 1-7 and the other for fractions 8-15. Daily cone beam computed tomography (CBCT) was performed and registered to planning-CT using bony anatomy. Within-patient comparisons of mean daily chest wall position were made using a paired t-test. Population, systematic (∑) and random errors (α) were estimated. Intrafraction reproducibility was assessed by comparing chest wall position and diaphragm movement between consecutive breath holds on CBCT. RESULTS: 16 patients were recruited. All completed treatment with both techniques (9 patients with wax bolus, 7 patients without). CBCT derived ∑ were 2.1-6.4 mm (ABC_DIBH) and 2.1-4.9 mm (vDIBH), α were 1.7-2.6 mm (ABC_DIBH) and 2.2-2.7 mm (vDIBH) and mean daily chest wall displacements (MD) were 0.0-1.5 mm (ABC_DIBH) and -0.1-1.6 vDIBH (all p non-significant). Chest wall and diaphragm position was equivalent between consecutive breath holds in ABC and vDIBH (median difference 1.0 mm and 0.8 mm respectively, non p significant) demonstrating equivalent intrafraction reproducibility. CONCLUSION: This study demonstrates that a simple voluntary breath hold technique is feasible in combination with VMAT (+/- bolus) and is as reproducible as ABC_DIBH with VMAT for the irradiation of the breast and axillary and IMC lymph nodes in breast cancer patients.
Citation
Clinical and translational radiation oncology, 2021, 27 pp. 164 - 168
Source Title
Publisher
ELSEVIER IRELAND LTD
ISSN
2405-6308
eISSN
2405-6308
Collections
Research Team
Breast Cancer Radiotherapy
Breast Cancer Radiotherapy
Breast Cancer Radiotherapy