Comparison of Intraoperative and Postoperative Boost Radiotherapy in Terms of Local Recurrence and Cosmetic Outcomes in Patients with Early-Stage Breast Cancer

To compare intraoperative (IO) and postoperative (po.) boost radiotherapy (RT) in terms of local recurrence and cosmetic outcomes in patients with early-stage breast cancer during breast-conserving therapy (BCT). Patients who received BCT at our clinic in the past 60 months were analyzed based on their recorded data. Ninety-eight patients who received IO boost RT during breast-conserving surgery were classified as group A and 99 who received po. boost whole-breast RTafterward were classified as group B. Patients were graded using the LENT-SOMA(V06-7/2003) scale and compared using the chi-square test based on local recurrence and cosmetic outcomes at 1 year after the end of all RTs. Mean age of patients in groups A and B was 49 and 52 years; mean follow-up was 35 and 38 months; tumor diameter was 18 (4-30) mm and 19 (6-30) mm; and lymph node involvement was observed in 11 and 17 patients, respectively. The molecular subtypes were either luminal A or B in both groups. Histological analysis revealed 90 and 84 invasive ductal carcinomas, 8 and 5 invasive lobular tumors, respectively, and 10 mixed structure in group B. The boost area was planned so as to cover 15-20 mm of the surrounding tumor bed area in both methods. Local recurrence was not detected in group A; however, itwas detected in two patients in group B at 20 and 32 months. According to the LENT-SOMA scale, 34 and 24 patients in groups A and B had grade 0, 41 each had grade 1, 21 and 29 had grade 2, and 2 and 5 had grade 3, respectively, but there was no significant difference between the two groups (p > 0.05). Based on the relatively superior results demonstrated by group A, IO boost RT can potentially improve both local control and cosmetic results.