Which type of breast positioning for irradiation is optimal for women with left-sided lesions?

The optimal positioning for irradiation in women with left-sided lesions is the prone position. This positioning allows the breast to be positioned away from the heart, reducing the amount of cardiac tissue exposed to radiation. This is particularly beneficial for left-sided breast irradiation, where there is a higher risk of inadvertently irradiating heart tissue, which could lead to cardiovascular complications later.

In the prone position, the patient lies on her stomach, which helps in fully irradiating the targeted breast area while minimizing radiation exposure to the heart and lungs. Additionally, this positioning can lead to improved treatment accuracy and effectiveness by keeping the tumor in a more consistent and optimal location throughout the treatment sessions.

Other positions like supine, standing, or seated could potentially allow for more heart exposure or may not effectively immobilize the breast tissue for optimal irradiation, making them less favorable choices in this context.