Believe it or not, radiation oncology and radiology are two completely different fields of medicine that have very little in common. A radiologist
is a doctor
who performs medical imaging procedures to look at structures within the body. They spend most of their time reading x-rays, CAT scans, and MRIs. They also spend there time performing biopsies under imaging guidance. If your mother ever has an ultrasound, an x-ray, or a CAT scan, the radiologist is behind the scenes making sure that nothing in her body goes unnoticed.
On the other hand, a radiation oncologist
(or radiotherapist) is a doctor who uses beams of radiation to kill cancer cells in the body. The doctor directs the beam of radiation directly at a tumor in order to kill the cancer cells and shrink the tumor. Radiation therapy is used in some, but not all cancer treatments. All cancer treatment plans involve imaging and thus, a radiology evaluation will definitely occur.
I suggest that you schedule an appointment with your mother's hematologist/oncologist. He or she will be to explain what your mother's breast cancer treatment will consist of. Most cancer treatment consists of surgery, chemotherapy, radiation therapy, immunotherapy, or some combination of all of them. Good luck.