Two-year follow-up of volumetric-modulated arc therapy for treating internal mammary nodes in locally advanced breast cancer

Background/Aim: We evaluated dosimetric and clinical results of volumetric-modulated arc therapy (VMAT) treating internal mammary nodes (IMNs) in patients with locally advanced breast cancer. Patients and Methods: Between July 2012 and December 2013, treatment outcomes of 31 patients with stage III breast cancer treated with postoperative radiotherapy including the IMN field using VMAT were analyzed. Results: The median follow-up was 25.2 months. VMAT showed good homogeneity and improved conformity. The incidence of lung toxicity of grade 2 or more was 3.2%, and cardiac toxicity was not observed. No patient developed local recurrence. Conclusion: VMAT appears safe for the treatment of locally advanced breast cancer including the IMN field.