1. Dosimetric benefit and clinical feasibility of deep inspiration breath-hold and volumetric modulated arc therapy-based postmastectomy radiotherapy for left-sided breast cancer.
- Author
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Wang SJ, Zhai YR, Zhang WW, Chen SY, Qin SR, Fang H, Tang Y, Song YW, Liu YP, Chen B, Qi SN, Tang Y, Lu NN, Li YX, Jing H, and Wang SL
- Subjects
- Humans, Female, Middle Aged, Radiotherapy Planning, Computer-Assisted methods, Aged, Adult, Radiometry, Inhalation, Lung radiation effects, Lung diagnostic imaging, Prospective Studies, Heart radiation effects, Heart diagnostic imaging, Breath Holding, Radiotherapy, Intensity-Modulated methods, Unilateral Breast Neoplasms radiotherapy, Unilateral Breast Neoplasms surgery, Unilateral Breast Neoplasms diagnostic imaging, Mastectomy, Feasibility Studies, Cone-Beam Computed Tomography, Radiotherapy Dosage
- Abstract
To evaluate the dosimetric benefits and clinical feasibility of deep inspiratory breath-hold (DIBH) combined with volumetric modulated arc therapy (VMAT) in left-sided postmastectomy radiotherapy (PMRT). Eligible patients with left-sided breast cancer undergoing DIBH-based PMRT were prospectively included. Chest wall, supra/infraclavicular fossa, and/or internal mammary node irradiation (IMNI) were planned with a prescription dose of 43.5 Gy in 15 fractions. VMAT plans were designed on free breathing (FB)-and DIBH-CT to compare dosimetric parameters in heart, left anterior descending artery (LAD) and lung. Cone-beam computed tomography (CBCT) was performed before and after treatment to evaluate inter- and intra-fractional setup errors. Heart position and dose variations during treatment were estimated by fusing CBCT with DIBH-CT scans.Twenty patients were included with 10 receiving IMNI. In total, 193 pre-treatment and 39 pairs pre- and post-treatment CBCT scans were analyzed. The D
mean , Dmax , and V5-40 of the heart, LAD, and left lung were significantly lower in DIBH than FB (p < 0.05 for all), except for V5 of LAD (p = 0.167). The cardiopulmonary dosimetric benefits were maintained regardless of IMNI. The inter- and intra-fractional setup errors were < 0.3 cm; and the overall estimated PTV margins were < 1.0 cm. During treatment, the mean dice similarity coefficient of heart position and the mean ratio of heart Dmean between CBCT and DIBH-CT plans was 0.95 (0.88-1.00) and 100% (70.6-119.5%), respectively. DIBH-VMAT could effectively reduce the cardiopulmonary doses with acceptable reproducibility and stability in left-sided PMRT regardless of IMNI., (© 2024. The Author(s).)- Published
- 2024
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