%0 Journal Article %T Interobserver variability (between radiation oncologist and radiation therapist) in tumor bed contouring after breast %A Eliana La Rocca %A Emanuele Pignoli %A Francesca Bonfantini %A Laura Lozza %A Maria Carmen De Santis %A Massimiliano Gennaro %A Michela Dispinzieri %A Riccardo Valdagni %A Sarah Frasca %A Serena Di Cosimo %A Tommaso Giandini %A Vanessa Lici %J Tumori Journal %@ 2038-2529 %D 2019 %R 10.1177/0300891619839288 %X To examine interobserver variability between the radiation oncologist (RTO) and the radiation therapist (RTT) in delineating the tumor bed (TB) in early breast cancer (BC). We retrospectively analyzed patients who received a radiotherapy boost to the TB. In a first group, the clinical target volume (CTV) for the boost was the surgical bed, defined by using surgical clips. In a second group, the CTV was defined by identifying a seroma cavity or a metallic find on the scar. These contours were compared in terms of volume, number of slices, and Dice similarity coefficient (DSC). Forty patients were assessed: 20 had surgical clips (group 1) while the other 20 had none (group 2). There was no difference in the number of slices contoured by the 2 operators for group 1, but a statistically significant difference emerged in the volumes: the RTT identified a TB that was a mean 45% smaller than the one identified by the RTO. Random differences were found between the 2 operators for group 2. The TBs delineated for this group were significantly larger (P<0.05) than those identified by the RTT for group 1. The mean Dice value between the RTO¡¯s and the RTT¡¯s TBs was 0.69¡À0.07 (range 0.53¨C0.81) for group 1 and 0.37¡À0.18 (range 0¨C0.58) for group 2 (P<0.05). This study showed that the use of clips coincided with less interoperator variability. With appropriate training, the RTT may play an important part in the multidisciplinary radiotherapy team %K Breast cancer %K tumor bed delineation %K interobserver variability %K surgical clips %U https://journals.sagepub.com/doi/full/10.1177/0300891619839288