Robotic Stereotactic Body Radiation Therapy for the Adjuvant Treatment of Early-Stage Breast Cancer: Outcomes of a Large Single-Institution Study

Purpose: Advancements in breast radiation therapy offer innumerable benefits to patients and the health care system. Despite promising outcomes, clinicians remain hesitant about long-term side effects and disease control with accelerated partial breast radiation therapy (APBI). Herein, we review the long-term outcomes of patients with early-stage breast cancer treated with adjuvantMethods and Materials: This retrospective study examined outcomes of patients who received diagnoses of early-stage breast cancer treated with adjuvant robotic SAPBI. All patients were eligible for standard ABPI and underwent lumpectomy, followed by fiducial placement in preparation for SAPBI. Using fiducial and respiratory tracking to maintain a precise dose distribution throughout the course of treatment, patients received 30 Gy in 5 fractions on consecutive days. Follow-up occurred at routine intervals to evaluate disease control, toxicity, and cosmesis. Toxicity and cosmesis were characterized using the Common Terminology Criteria for AdverseResults: Patients (N = 50) were a median age of 68.5 years at the time of treatment. The median tumor size was 7.2 mm, 60% had an invasive cell type, and 90% were estrogen receptor positive, progesterone receptor positive, or both. Patients (n = 49) were followed for a median of 4.68 years for disease control and 1.25 years for cosmesis and toxicity. One patient experienced local recurrence, 1 patient experienced grade 3+ late toxicity, and 44 patients demonstrated excellent cosmesis.Conclusions: To our knowledge, this is the largest retrospective analysis with the longest follow-up time for disease control among patients with early breast cancer treated with robotic SAPBI. With follow-up time for cosmesis and toxicity comparable to that of previous studies, results of the present cohort advance our understanding of the excellent disease Jaysing Oncology: March-April control, excellent cosmesis, and limited toxicity that can be achieved by treating select patients with early-stage breast cancer with robotic SAPBI.& COPY; 2022 The Author(s). Published by Elsevier Inc. on behalf of American Society for Radiation Oncology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).