What needs radiotherapy after total mastectomy for breast cancer?
Radiotherapy after total mastectomy for breast cancer can reduce the 5-year local recurrence rate to 1/4 to 1/3 of the original rate in patients with positive axillary lymph nodes.
Patients with one of the following prognostic factors are eligible for high-risk recurrence and have indications for postoperative radiotherapy.
1. The maximum diameter of the primary tumor is greater than or equal to 5 cm, or the tumor invades the breast skin or chest wall.
2.Lymph node metastasis in the axilla greater than or equal to 4.
3.Stage T1-2 patients with one to three axillary lymph node metastases, such as those with one of the following factors: age less than or equal to 40 years old, metastasis proportion greater than 20% when the number of axillary lymph nodes is less than 10, hormone receptor negative, HER2 overexpression, high histological grade, and positive vasculature, etc., the current data also support the value of postoperative radiotherapy, and the benefits and risks of radiotherapy should be weighed.
4.After mastectomy alone in patients with stage T1-2, if the sentinel lymph node biopsy is positive, postoperative radiotherapy is recommended when subsequent axillary clearance is not considered; if radiotherapy is not considered, further axillary clearance is recommended.
5.Patients with neoadjuvant chemotherapy refer to the initial staging before chemotherapy, and the indications and dose of radiotherapy are the same as that of modified radical postoperative radiotherapy without neoadjuvant treatment.
The indications of postoperative radiotherapy for breast reconstruction patients follow the same period of patients after mastectomy, and the technique of radiotherapy after breast reconstruction can refer to whole breast radiotherapy after breast-conserving surgery.
When should radiotherapy be given after total mastectomy for breast cancer?
1. If chemotherapy is needed, it is recommended to start within 2 to 4 weeks after the last chemotherapy is completed.
2.For those who do not need chemotherapy, postoperative radiotherapy should be started after the incision is healed and the upper limb function is restored.
3.Endocrine therapy and radiotherapy can be started simultaneously or after radiotherapy.
4.Patients with targeted therapy (trastuzumab) can be treated simultaneously with radiotherapy as long as their heart function is normal before radiotherapy.
5.In addition, the indications for radiotherapy in the internal breast area need to be strictly controlled, and the volume and dose of cardiac irradiation should be reduced as much as possible for patients on the left side.
Target areas for radiotherapy after total mastectomy
1.Since chest wall and supraclavicular are the most common recurrence sites, accounting for about 80% of all recurrence sites, these two areas are the main target areas for postoperative radiotherapy; however, patients with T3N0 can consider chest wall irradiation alone.
(2) The absolute value of internal breast lymph node recurrence is low, and the indications for internal breast radiotherapy are still controversial; internal breast field irradiation can be carefully considered after assessing the safety of cardiac dose.
(1) Internal breast field irradiation is recommended for patients with a high likelihood of internal breast lymph node metastasis diagnosed by pre-treatment imaging or confirmed by intraoperative biopsy.
(2) Patients whose primary tumor is located in the medial quadrant and has metastasis in the axillary lymph nodes or other patients with a high probability of metastasis in the internal breast lymph nodes.
(3) In principle, to avoid the superimposition of cardiotoxicity between targeted therapy and internal breast irradiation, internal breast field irradiation is recommended with caution.