AUTHOR=Jacob Julian , Heymann Steve , Borget Isabelle , Dumas Isabelle , Riahi Elyes , Maroun Pierre , Ezra Patrick , Roberti Elena , Rivera Sofia , Deutsch Eric , Bourgier Céline 

TITLE=Dosimetric Effects of the Interfraction Variations during Whole Breast Radiotherapy: A Prospective Study

JOURNAL=Frontiers in Oncology

VOLUME=5

YEAR=2015

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2015.00199

DOI=10.3389/fonc.2015.00199

ISSN=2234-943X

ABSTRACT=<sec id="ST1"><title>Introduction</title><p>The aim of this work was to assess the dosimetric impact of the interfraction variations during breast radiotherapy.</p></sec><sec id="ST2"><title>Materials and methods</title><p>Daily portal imaging measurements were prospectively performed in 10 patients treated with adjuvant whole breast irradiation (50 Gy/25 fractions). Margins between the clinical target volume and the planning target volume (PTV) were 5 mm in the three dimensions. Parameters of interest were the central lung distance (CLD) and the inferior central margin (ICM). Daily movements were applied to the baseline treatment planning (TP1) to design a further TP (TP2). The PTV coverage and organ at risk exposure were measured on both TP1 and TP2, before being compared.</p></sec><sec id="ST3"><title>Results</title><p>A total of 241 portal images were analyzed. The random and systematic errors were 2.6 and 3.7 mm for the CLD, 4.3 and 6.9 mm for the ICM, respectively. No significant consequence on the PTV treatments was observed (mean variations: +0.1%, <italic>p</italic> = 0.56 and −1.8%, <italic>p</italic> = 0.08 for the breast and the tumor bed, respectively). The ipsilateral lung and heart exposure was not significantly modified.</p></sec><sec id="ST4"><title>Conclusion</title><p>In our series, the daily interfraction variations had no significant effect on the PTV coverage or healthy tissue exposure during breast radiotherapy.</p></sec>