In Reply We thank Lin and colleagues for the comments on our study comparing survival following breast conservation vs mastectomy.1 As the authors confirm, whole-breast radiotherapy was a requirement for all individuals in our study undergoing breast-conserving surgery, and those in whom it was omitted (n = 2390) were excluded from analysis.1 Although we agree that the register we used does not give full details on given radiotherapy, we are confident that we can discern local (ie, whole-breast after breast-conserving surgery or chest wall after mastectomy) from locoregional radiotherapy (including the above-local target but adding regional nodal fields). In a 2021 publication from our group using the same Swedish national register, we individually scrutinized the medical records of 4294 patients undergoing breast-conserving surgery from 2010 to 2016 and found that dose and fractionation rarely differed from guideline recommendations.2 Hence we are confident that deviations from the standard dose (50 Gy, with an additional boost dose for those younger than 50 years) and fractionation (n = 25) were uncommon in our study. During the relevant years (2008-2017), partial breast irradiation was not used in Sweden. Thus, the present study does not and cannot make any assumptions regarding the advantages or disadvantages of partial breast irradiation, and we cannot underpin or contradict the statement by Lin and colleagues regarding the cosmetic benefits of such radiotherapy. That is assuming that the term locoregional radiotherapy in their Letter indeed regards partial breast irradiation according to the Intraoperative Irradiation for Early Breast Cancer (ELIOT) trial and not true locoregional radiotherapy as defined above.