Outcomes of targeted axillary radiation therapy with omission of axillary dissection in early breast cancer patients with one or two positive sentinel lymph nodes and extracapsular extension

对于早期乳腺癌患者，若仅有1或2个前哨淋巴结阳性且存在包膜外侵犯，则采用靶向腋窝放射治疗而不行腋窝淋巴结清扫术的疗效如何？