TY - JOUR AU - Al-Hammadi, Noora AU - Caparrotti, Palmira AU - Divakar, Saju AU - Riyas, Mohamed AU - Chandramouli, Suparna AU - Hammoud, Rabih AU - Hayes, Jillian AU - Mc Garry, Maeve AU - Paloor, Satheesh AU - Petric, Primoz PY - 2017/06/07 Y2 - 2024/03/29 TI - MRI reduces variation of contouring for boost clinical target volume in breast cancer patients without surgical clips in the tumour bed JF - Radiology and Oncology JA - Radiol Oncol VL - 51 IS - 2 SE - Clinical oncology DO - UR - https://radioloncol.com/index.php/ro/article/view/2735 SP - AB - <p><strong>Introduction: </strong>Omitting the placement of clips inside tumour bed during breast cancer surgery poses a challenge during delineation of lumpectomy cavity clinical target volume (CTV<sub>LC</sub>). We aimed to quantify inter-observer variation and accuracy for CT- and MRI-based segmentation of CTV<sub>LC</sub> in patients without clips.</p><p><strong>Materials and methods: </strong>CT- and MRI-simulator images of 12 patients, treated by breast conserving surgery and radiotherapy, were included in this study. Five radiation oncologists recorded the Cavity Visualization Score (CVS) and delineated CTV<sub>LC</sub> on both modalities. Expert-consensus (EC) contours were delineated by a senior radiation oncologist, respecting opinions of all observers. Inter-observer volumetric variation and generalized conformity index (CI<sub>gen</sub>) were calculated. Deviations from EC contour were quantified by the accuracy index (AI) and inter-delineation distances (IDD).</p><p><strong>Results: </strong>Mean CVS was 3.88 +/- 0.99 and 3.05 +/- 1.07 for MRI and CT, respectively (p=0.001). Mean volumes of CTV<sub>LC</sub> were similar: 154 +/- 26 cm<sup>3 </sup>on CT and 152 +/- 19 cm<sup>3</sup> on MRI. Mean CI<sub>gen</sub> and AI were superior for MRI when compared with CT (CI<sub>gen</sub>: 0.74 +/- 0.07 vs. 0.67 +/- 0.12, p=0.007; AI: 0.81 +/- 0.04 vs. 0.76 +/- 0.07; p=0.004). CI<sub>gen</sub> and AI increased with increasing CVS.  Mean IDD was 3 mm +/- 1.5 mm and 3.6 mm +/- 2.3 mm for MRI and CT, respectively (p=0.017).</p><p><strong>Conclusions:</strong> When compared with CT, MRI improved visualization of post-lumpectomy changes, reduced the inter-observer variation and improved the accuracy of CTV<sub>LC</sub> contouring in patients without clips in the tumour bed.<em></em></p> ER -