CyberKnife for Breast Cancer

Accelerated Partial Breast Irradiation

The main effect of radiation therapy following breast conserving surgery is the reduction of breast cancer recurrence. Whole breast Irradiation (WBI) delivers daily radiation to the entire breast through a few angles over the course of 6-7 weeks. A shorter course (1 week) of radiation therapy restricted to the region around the tumor bed, called accelerated partial breast irradiation (APBI) has been introduced. For select patients, the results are very encouraging and the techniques have been shown to be safe and tolerable with outcomes similar to WBI.

If radiation is directed only to the tissue surrounding the excision cavity, then the entire course of radiation therapy can be shortened to one week, which is more convenient for the patient. Furthermore, APBI decreases the doses administered to normal tissues, such as the remainder of the breast, underlying muscle, ribs, lung, and heart thus potentially reducing toxicities. Unlike most APBI techniques, CyberKnife® does not require an in-dwelling brachytherapy catheter.

With this IRB-approved protocol, CyberKnife® is expected to result in a more conformal, convenient treatment schedule and with less discomfort than other APBI techniques that require a brachytherapy catheter.

CyberKnife® Advantages

  • CyberKnife® Advantages over Conventional Radiation Treatment:
    • A shorter and more convenient course of radiation (1-2 weeks versus 6-7 weeks)
    • Less radiation exposure to surrounding normal structures (lung, heart, chest wall, breast, and lymphatic system)
    • Decreased radiation treatment delay in patients who need chemotherapy
  • CyberKnife ® Advantages over other Partial Breast Brachytherapy:
    • Avoids implanting a catheter into the breast which is an additional invasive procedure that is required with Brachytherapy
    • Since there is no in-dwelling catheter in the breast, there is less discomfort and no risk of infection and bleeding
    • Enables patients with varied anatomy and difficult tumor location to be eligible

Treatment Comparison



HDR Brachytherapy

External Beam Therapy

Treatment Area

A portion of the breast = Tumor site with about 1 cm margin only

Tumor site with margins only

Entire breast

Number of Treatments

10 treatments in 1 or 2 weeks

10 treatments in one week

35-37 treatments over 6-7 weeks


More convenient, for those with busy schedule or long commute to the clinic

More convenient for those with busy work schedules, or long commutes

Greater time commitment required

Radiation to Adjacent Organs

Less radiation to the lung, heart, ribs, and lymphatic system

Less radiation to lung, heart, ribs, and lymphatics

Acceptable radiation to lung, heart, ribs and lymphatics


Required insertion of tiny metallic markers for tracking

Yes, requires surgical placement of catheters

No, external x-rays only

Skin Care

Minimal skin care

Requires bandaging and care of catheter sites

Daily application of creams

Cure Rates

Expected to be the same; under IRB-approved clinical study

Promising results, 5 year follow-up

Proven track record for > 20 years


Expected to be the same or better.

Favorable, minimal scarring

Favorable in most instances


The American Cancer Society estimated that 184,450 new cases of invasive breast cancer were diagnosed and 40,930 died of breast cancer in the United States in 2008. Approximately 67,770 women were diagnosed with carcinoma in situ of the breast during the same year. Breast cancer is the most common malignancy in women in the United States and is second only to lung cancer as a cause of cancer death.

The incidence of breast cancer has increased steadily in the United States over the past few decades, but breast cancer mortality appears to be declining, suggesting a benefit from early detection and more effective treatment.

CyberKnife® treatment enables patients to undergo their radiotherapy treatment and immediately resume normal daily activities. The treatment requires minimal or no sedation and has a low risk of complications. It is completed in a period of 1-2 weeks with 10 treatments lasting approximately one hour each. The treatment is virtually painless.

The IRB approved protocol developed by CyberKnife Centers of San Diego uses CyberKnife® as a method to treat breast cancer following breast conserving surgery.

To find out if you or your patients can benefit from this study, please contact us by calling any of our numbers listed below or by filling out our contact form.