Anatomic features of interest in women at risk of cardiac exposure from whole breast radiotherapy. Issue 3 (June 2015)

• Record Type: Journal Article
• Authors: Lee, Grace; Rosewall, Tara; Fyles, Anthony; Harnett, Nicole; Dinniwell, Robert E.
• Is Part Of: Radiotherapy and oncology. Volume 115:Issue 3(2015:Jun.)
• Page Start: 355
• Page End: 360
• Publication Date: 2015-06
• Subjects: Oncology -- Periodicals; Radiotherapy -- Periodicals; Tumors -- Periodicals; Medical Oncology -- Periodicals; Neoplasms -- radiotherapy -- Periodicals; Radiotherapy -- Periodicals; Radiothérapie -- Périodiques; Cancérologie -- Périodiques; Tumeurs -- Périodiques; Electronic journals; 616.9940642
• DOI: 10.1016/j.radonc.2015.05.002
• Languages: English
• ISSNs: 0167-8140

Abstract

<abstract xml:lang="en" abstract-type="author" id="ab005"> <title id="st005">Abstract</title> <sec> <title id="st010">Background and purpose</title> <p id="sp0005">Left-sided breast radiotherapy (RT) can result in cardiac exposure. This study aims to identify predictive anatomic features in women requiring breath-hold (RT<sub>BH</sub>) for cardiac sparing during adjuvant whole breast RT.</p> </sec> <sec> <title id="st015">Material and methods</title> <p id="sp0010">We retrospectively reviewed free-breathing (FB) CT scans of 80 women previously treated with left-sided breast RT. Unfavourable cardiac anatomy was defined as the number of consecutive axial CT slices (2 mm) in which the anterior chest wall contacted the heart (Contact<sub>Heart</sub>) or left ventricle (Contact<sub>LV</sub>). The sternal angle and Haller Index (HI) were used to measure chest concavity. Position and volume of post-operative cavity was also quantified.</p> </sec> <sec> <title id="st020">Results</title> <p id="sp0015">Heart mean dose (<italic>D</italic><sub>mean</sub>) was strongly correlated with Contact<sub>LV</sub> (<italic>r</italic> = 0.625, <italic>p</italic> < 0.001) and Contact<sub>Heart</sub> (<italic>r</italic> = 0.524, <italic>p</italic> < 0.001) but not significantly correlated with tumor size, cavity volume, heart volume, cavity distance to chest wall, sternal angle, or HI. ROC analysis of Contact<sub>Heart</sub> was most predictive of the need for breath-hold (RT<sub>BH</sub>) technique [Area Under Curve = 0.815 (SE: 0.048; 95% CI: 0.721–0.91)] and ⩾25 Contact<sub>Heart</sub> CT slices predicted for heart <italic>D</italic><sub>mean</sub> ⩾1.7 Gy (68% sensitivity and 82% specificity).</p> </sec> <sec> <title id="st025">Conclusion</title> <p id="sp0020">Contact<sub>Heart</sub> on FB CT of ⩾25 axial slices (2 mm), ⩾50 mm of para-sagittal heart contact, was predictive of higher heart <italic>D</italic><sub>mean</sub> and suggest a potential need for RT<sub>BH</sub>.</p> </sec> </abstract>