Details

Autor(en) / Beteiligte

• Kirby, Anna M
• Evans, Philip M
• Donovan, Ellen M
• Convery, Helen M
• Haviland, Joanna S
• Yarnold, John R

Titel

Prone versus supine positioning for whole and partial-breast radiotherapy: A comparison of non-target tissue dosimetry

Ist Teil von

• Radiotherapy and oncology, 2010-08, Vol.96 (2), p.178-184

Ort / Verlag

Ireland: Elsevier Ireland Ltd

Erscheinungsjahr

2010

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Abstract Purpose To compare non-target tissue (including left-anterior-descending coronary-artery (LAD)) dosimetry of prone versus supine whole (WBI) and partial-breast irradiation (PBI). Methods and materials Sixty-five post-lumpectomy breast cancer patients underwent CT-imaging supine and prone. On each dataset, the whole-breast clinical-target-volume (WB-CTV), partial-breast CTV (tumour-bed + 15 mm), ipsilateral-lung and chest-wall were outlined. Heart and LAD were outlined in left-sided cases ( n = 30). Tangential-field WBI and PBI plans were generated for each position. Mean LAD, heart, and ipsilateral-lung doses ( xmean ), maximum LAD (LADmax ) doses, and the volume of chest-wall receiving 50 Gy ( V50Gy ) were compared. Results Two-hundred and sixty plans were generated. Prone positioning reduced heart and LAD doses in 19/30 WBI cases (median reduction in LADmean = 6.2 Gy) and 7/30 PBI cases (median reduction in LADmax = 29.3 Gy) (no difference in 4/30 cases). However, prone positioning increased cardiac doses in 8/30 WBI (median increase in LADmean = 9.5 Gy) and 19/30 PBI cases (median increase in LADmax = 22.9 Gy) (no difference in 3/30 cases). WB-CTV > 1000cm3 was associated with improved cardiac dosimetry in the prone position for WBI ( p = 0.04) and PBI ( p = 0.04). Prone positioning reduced ipsilateral-lungmean in 65/65 WBI and 61/65 PBI cases, and chest-wall V50Gy in all WBI cases. PBI reduced normal-tissue doses compared to WBI in all cases, regardless of the treatment position. Conclusions In the context of tangential-field WBI and PBI, prone positioning is likely to benefit left-breast-affected women of larger breast volume, but to be detrimental in left-breast-affected women of smaller breast volume. Right-breast-affected women are likely to benefit from prone positioning regardless of breast volume.