Evaluating Outcomes of Breast-Conserving Surgery and Intraoperative Radiotherapy in Early-Stage Breast Cancer: A 3-Year Follow-Up Study in Iran

One of the most common procedures performed in radiation therapy centers is breast-conserving radiation therapy for breast cancer. This study aimed to evaluate the outcomes of surgery combined with minimally invasive radiation therapy in patients with early-stage breast cancer. This mixed cohort study (incorporating both retrospective and prospective data) was conducted on 153 patients who underwent surgery and minimally invasive radiation therapy for breast cancer at Pastor Hospital in Mashhad, Iran. During the surgical procedure, patients underwent breast-conserving surgery using the oncoplastic resection technique, along with sentinel axillary lymph node biopsy. Post-surgery, patients received radiotherapy using the Zeiss Intrabeam device. The study assessed adverse events and breast cancer recurrence rates to evaluate the safety and efficacy of this treatment approach. Data were analyzed using SPSS version 22 software. The mean age of the patients was 55.74 ± 8.89 years, and the average time from diagnosis to treatment was 36.73 ± 10.41 months. Subcutaneous toxicity, graded according to severity, was observed as follows: 61 patients (59.8%) were at stage 0, 33 patients (32.4%) at stage 1, 3 patients (2.9%) at stage 2, and 5 patients (4.9%) at stage 3. Tumor recurrence was observed in 10 cases (10.1%) of invasive cancer and in one patient (1%) with bedside tumor. Positive HER2neu status (p-value = 0.04) and lymphovascular invasion (LVI) (p-value = 0.02) were significantly associated with three-year survival rates. The findings of this study, consistent with other research, demonstrate that surgical treatment combined with minimally invasive radiation therapy for early-stage breast cancer yields favorable outcomes, including acceptable three-year survival rates, low recurrence rates, and minimal complications. However, due to the study's limitations—such as the small sample size and short follow-up period—further research with larger patient cohorts and longer follow-up durations is recommended to validate these results.