**10. Evaluation of the breast after surgical therapy**

Breast imaging is a challenge in evaluating postoperative changes in breast cancer breast due to the wide range of imaging changes after surgery and the risk of recurrent disease. Ultrasound findings depending on the type of surgery performed: mastectomy, breast-conserving therapy, and breast reconstruction; whether radiation therapy has been performed; and the period elapsed from the end of treatment. Breast Ultrasound should perform in addition to, not as a replacement for, mammography [96, 97], for women who have undergone breast-conserving surgery and for the surgical site in patients with mastectomy. There are no post-mastectomy imaging guidelines since they are followed clinically with serial physical examinations. In the absence of breast reconstruction, the chest wall, subcutaneous fat, and skin can be evaluated with ultrasonography [98]. Cutaneous recurrence in patients after mastectomy may be palpable superficial mass.

Understanding the postsurgical imaging findings and their correlation is essential to ensure an accurate interpretation and recommendation. The most common changes in US imaging after breast-conserving surgery are:


sometimes with debris or septa. Hematomas may be ill-defined or present as a mass with distal acoustic enhancement or shadowing and internal complex echoes [10]. Postoperative fluid collection decreases by six months, though, in a few patients, these may persist for years [100].

• Fat necrosis appears as hypoechoic or heterogeneous irregular mass, with acoustic shadowing. These findings may be misinterpreted as suspicious for malignancy. Therefore, in this case, correlating mammographic findings and tissue sampling is indicated (**Figure 6**).

### **Figure 6.**

*US Postoperative changes in Breast Conservation Treatment. (a) Parenchymal Edema, represented by reticular enlargement of breast parenchyma with dilated lymphatics (calipers) and interstitial fluid; (b) Postsurgical Scar, a discrete area of hypoechoic distortion with strong acoustic shadowing; (c) Postoperative Fluid Collection in surgical bed; (d) Fat Necrosis: Heterogeneous mass with acoustic shadowing.*
