Radiation Oncology is an integral part of the Comprehensive Multidisciplinary Breast Service. The application of radiation therapy along with limited surgery revolutionized the outcome of patients with breast cancer. This combination therapy spares women from undergoing a modified radical mastectomy and maximizes local control while preserving the breast. The Department features the state-of-the-art technology and facilities that offer our patients the latest advances in radiation treatment. In addition, our experienced and accomplished faculty members are leaders in the field of radiation oncology. Our staff members are dedicated to providing patients with the individualized attention they need.

There are two types of radiation therapy used in the treatment of breast cancer-external beam radiation therapy and brachytherapy. External beam radiation therapy uses high-energy X-rays to deliver radiation therapy to the target tissues, while brachytherapy is a procedure in which radiation therapy is delivered by the application of sealed radioactive seeds placed directly into or near the target tissues. Our faculty has extensive expertise in both types of radiation, and we are on the leading edge of innovative new techniques for radiation delivery.


Three-Dimensional Conformal External Beam Radiation Therapy

Computerized radiation therapy planning and delivery known as three-dimensional conformal external beam radiation therapy, the radiation beams enter and exit specific points on the body from different angles. Some beams may be filtered to adjust the intensity of radiation delivered. These adjustment allows selective concentration of radiation dose in the region of the cancer, and minimize the dose to the surrounding normal organs.

Intensity Modulated Radiation Therapy

Intensity modulated radiation therapy (IMRT) is one of the latest technologies used for radiation therapy delivery. IMRT optimizes radiation delivery by employing a computer-aided algorithm to repeatedly adjust the intensity of each of the hundreds of segments of distinct radiation beams. This technology enhances the ability to precisely tailor the radiation delivery to the specific needs of each patient.


Brachytherapy, delivers radiation using radioactive seeds that are implanted directly into the tumor or tumor bed. In the treatment of breast cancer these implanted seeds remain in the body temporarily either for a few minutes (high dose rate technique) or for several days (low dose rate technique). In this manner the prescribed dose of radiation therapy is directly delivered to the affected area minimizing radiation exposure to the surrounding healthy tissue. Brachytherapy is also used for recurrent cancers, as a way of re-treating an area that was previously irradiated. There are several brachytherapy techniques applicable to the treatment of breast cancer.

Brachytherapy techniques

Multi-catheter brachytherapy system: In this procedure plastic ribbons are placed in the lumpectomy cavity through which the radioactive seeds are thread and left in place temporarily to deliver the treatment. This technique targets areas around the lumpectomy cavity where the tumor is most likely to recur. Beth Israel offers this brachytherapy treatment on a clinical trial for treating locally recurrent breast cancer.

MammoSite Radiation Therapy System: The MammoSite device uses a single applicator with a balloon at the tip of a catheter, which is inserted into the cavity created by a lumpectomy, simplifying a procedure that was previously required the use of multiple catheters. Brachytherapy is then delivered using tiny radioactive pellets. This technique like the multi-catheter technique targets areas around the lumpectomy cavity where the tumor is most likely to recur. The minimally invasive MammoSite approach offers a shortened treatment time and makes it easier for more women with early-stage breast cancer to consider the choice of lumpectomy.

Intraoperative Radiation Therapy (IORT): requires the special skills of both a radiation oncologist and a surgeon. This procedure utilizes an advanced computer planning system to deliver a single high dose of radiation during surgery to an area from which a tumor has just been removed. We perform this technique in a special, shielded operating room that enables our surgeons and radiation oncologists to significantly intensify treatment. We are one of only a few institutions in the country that offers this form of therapy, and Mount Sinai Health System physicians have led the way in the development of IORT procedures.


Accelerated Radiation Therapy in Early Stage Breast Cancer with an In-field Concomitant Boost using either IMRT or the 3D Conformal Radiation Therapy Technique.

Lumpectomy and Brachytherapy as Salvage Treatment for Local Recurrences Following Breast Conservative Therapy.

For information on clinical studies, click here.

Breast Surgery Division
Mount Sinai Beth Israel

Susan Boolbol MD, FACS
Division of Breast Surgery

Sarah Cate MD
Attending Surgeon

Alyssa Gillego MD
Attending Surgeon

Christopher Mills MD
Attending Surgeon