Radiation therapy is a safe treatment option which can be applied for treatment of all stages of breast cancer. For patients post lumpectomy or mastectomy with stage 0 through stage III breast cancer to patients with stage IV cancer that has spread to other parts of the body radiation therapy is used for treatment for breast cancer.
After lumpectomy it is typically recommended if the breast cancer is an early stage cancer which is 4 centimeters or smaller, located in one site and during surgery it was removed with clear margins.
In mastectomy breast removal, tissue which is behind the skin in front of the breast or back along the muscle behind the breast is the hardest to remove and some cancer cells may be left behind post the surgery in the healthy tissue. Based on the findings in the pathology report, the treating doctor may recommend radiation therapy post surgery typically in cancers which are 5 centimeters or larger. The cancer may be spread in microscopic lumps or can be 1 lump or a series of lumps which together are 5 centimeters or larger. As these have high recurrence risk. Also radiation is advised for patients post mastectomy when the lymph channels and blood vessels have been invaded by the cancer in the breast. Also if the removed tissue has a positive margin of resection and skin has been invaded by the cancer, radiotherapy is used. As cancer spread to four or more lymph nodes OR, for premenopausal women, at least 1 lymph node pose high recurrence risk for breast cancer, post surgery radiation is recommended.
Based on these various factors, patient may be at high or moderate risk for cancer recurrence and development. Radiation is NOT appropriate if the woman is pregnant as it can harm the embryo, or if the patient has already been exposed to full length radiation, in cases when patient has a connective tissue disease, such as scleroderma or vasculitis, making her extra-sensitive to the side effects of radiation. In radiation a daily commitment is required to get the full dose radiation.
Repetition of radiation is only done to one particular part of the body, if that part was not exposed to the full dose of radiation. Full dose is only given once, because of the tolerance limit of the body tissue. The optimum dose would ensure that the cancer tissue received the maximum therapeutic dose with no or minimum side effect to the surrounding healthy tissue. Once the full dose which the body’s healthy tissue can handle has been given to the tissue, the areas cannot be exposed to another full dose radiation. If required radiation will given as per the doctors advise. Whereas for another part of the body a full dose radiation can be given, if it has not been exposed to radiation.
The radiation timing is individual to different patients and type of breast cancer. In some cases radiation may follow surgery and possible hormonal therapy may be given later. In cases where chemotherapy is part of treatment plan, surgery is followed by chemotherapy, which is followed by radiation therapy and possible hormonal therapy later. Some cases also see start of the treatment with chemotherapy, targeted therapy, or hormonal therapy followed by surgery, then radiation and lastly possible hormonal therapy.
When radiotherapy follows surgery in external beam radiation, the tissue is exposed usually in about 3 to 6 weeks after surgery. Partial-breast radiation is usually given immediately after surgery and in the operating room during surgery, Intraoperative radiation is given just after the cancer tissue has been removed but before the opening in the skin.