The choice of postoperative radiotherapy for breast cancer involves comparing the tangential wild breast dose with radiation therapy, which most scholars certainly agree on as being r-_1. However, there is less discussion in the literature regarding radical radiotherapy treatment planning. Based on 2 () early-stage breast cancer patient cases, this article focuses on how to use computers to develop radiation treatment plans for breast cancer, specifically concerning the tangential wild and internal mammary wild doses, providing references for colleagues.
### Materials and Methods
#### Patient Data
A total of 20 patients with early-stage breast cancer were included, all of whom were women. All patients underwent conservative surgery and were pathologically confirmed. The maximum age was 68 years, the minimum age was 26 years, with a mean age of 47 years.
#### Tangential Wild Method for Breast Cancer Lymphatic Drainage
Breast cancer lymphatic drainage has three main areas: axillary, internal mammary, and supraclavicular. Therefore, the target volume includes the breast, internal mammary lymph node chain, axillary lymph nodes, and supraclavicular lymph nodes. Accordingly, the clavicle Ueno, breast tangential wild, and internal mammary wild are delineated.
Using the simulator, the lower bound of the wild on the clavicle, breast tangential Ueno, is determined. The upper bound of the supraclavicular wild is set at 0.5 cm below its lower bound. The lower bound in the internal mammary area is set at the level of the sternum midline parasternal or midaxillary line/posterior axillary line, serving as the baseline for tangent angle changes. According to the tumor location, the center axis of the inner and outer tangent fields is aligned in a straight line, while the lung is cut according to the depth of <3.0 cm. To determine the tangent wild tick light field, the projected line on the skin is used, pushing 30-50 cm for the internal mammary sector. Phantom maps supply schemes based on nipple levels.
#### Design Method
Using a mouse phantom diagram of the membrane and internal mammary, internal mammary points are lost using eight computers (CMS production). The internal mammary is generally away from the surface by 30-40 cm deep, determining the tangent wild and internal mammary wild. The tangent wild uses an 8MV X-ray, while the internal mammary wild uses a 14MeV parallel line with the tangent wild. A 17MeV line forms a 9-degree difference with the tangent field, determining the internal mammary wild. Using endo: exo: internal mammary wild tumor dose ratios of 1:1:1, the internal mammary point dose is set at 60% of the breast tangent wild dose (Figure 1). When gradually increasing the internal mammary field dose, the internal mammary field dose distribution becomes uniform, with the endo: exo: internal mammary wild dose ratio changing to 1:1:18-22, resulting in different dose distributions (Figures 2, 3, 4).
In Figures 1 to 4, the tumor dose ratios given in the breast, chest wall, and internal mammary are shown via DVH. The figure shows that the tangent wild and internal mammary wild dose equal the internal mammary field day dose. When gradually increased to the endo: exo internal mammary field dose of 1:1:1.8-20, the breast, chest wall, and internal mammary satisfy the dose distributions, further increasing the dose ratio of the internal mammary wild. The internal mammary and chest wall will become high-dose regions.
### Discussion
Our results show that when the endo wild: exo wild breast wild dose is lower than 1:1:1.8, there will be a significantly low dose region in the internal mammary. This could cause local recurrence after radiotherapy, as reported in the literature where local recurrence rates for conservative surgery and root activity slaughter are less than 10%, reminding clinical workers. It is not caused by the insufficient amount of tumor tissue leading to local recurrence but rather when the internal mammary wild doses higher than 1120, causing the plan area to have so-called hot spots of the high dose region. This may lead to excess exposure of the thoracic wall and internal mammary Carpenter organizations, contrary to clinical outcomes. When the endo wild: exo wild: internal mammary wild dose ratio is 1:1.8-20, the dose distribution curve for the breast, chest wall, and internal mammary synthesis is very perfect. Meeting the clinical dose of science four principles may involve the breast area's two wild contributions to the internal mammary, which is a wild contribution of anatomical differences in different individuals, resulting in the internal mammary dose ranging from 18 to 20. Thus, clinicians must grasp the breast cancer radiation treatment planning:
1. The breast dose must be exact.
2. Internal mammary wild should converge at the wall or breast tissue without producing low-dose or high-dose regions.
3. Minimize irradiation of mediastinum and lung tissue.
4. Adjust the breast lesion and thoracic width, dose ratio accordingly.