Voluntary breath-holding for breast cancer radiotherapy is consistent and stable
Voluntary breath-holding for breast cancer radiotherapy is consistent and stable
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DOI:
10.1259/bjr.20150309
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发表时间:
2015-01-01
影响因子:
2.6
通讯作者:
Donovan, Ellen M.
中科院分区:
文献类型:
--
作者:
Colgan, Ruth;James, Matthew;Donovan, Ellen M.
Objective: To evaluate breath-hold stability and constancy for a voluntary breath-hold (VBH) technique in a retrospective analysis.Methods: Movie loop sequences of electronic portal image data from multiple breath holds in a cohort of 19 patients were used to assess within and between breath-hold stability. In vivo dosimetry data based on electronic portal imaging (EPI) were analysed for 31 VBH patients plus a cohort of free-breathing (FB) patients to provide a reference. A phantom experiment simulated the impact on dose of FB, breath hold and unplanned release of breath hold.Results: 165/174 (93%) movie loop data sets had no detectable displacement. For the remaining 12, median displacement = 1.5 mm and maximum displacement = 3 mm (one patient on one fraction). In vivo dosimetry data analysis showed a median dose difference measured to planned of 20.2% (VBH) and -0.1% (FB). Dose distribution evaluation (gamma) pass rates were 84% (VBH) and 91% (FB) including the lung region; 93% and 96% with a lung override. Unplanned release of phantom breath-hold position changed median dose by