CyberKnife & Other Recent Developments in Breast Radiation Treatments

Radiation oncology has seen some impressive advances in treatment technology including robotic radiation delivery, accelerated radiation programs, and prone breast boards.

In light of increasing advancements in the field, NYU Winthrop Hospital recently established a full Department of Radiation Oncology as opposed to a Division under the Department of Radiology. This separate department recognizes the unique services of Radiation Oncology as a specialty. As the department’s new Chairman, it is with excitement that I am able to write about some of these new developments in radiation treatment.

CyberKnife® Robotic Radiation Delivery

The CyberKnife, manufactured by Accuray, is a robotic radiation delivery system that delivers radiation with a miniaturized linear accelerator, which generates high energy photons designed to target cancer cells.

Historically, radiation therapy was delivered by machines in a gantry, using a record-player type circular motion, rotating around a central point, which was limiting. The CyberKnife is the first of its kind to use a robotic arm, complete with a robotic shoulder, elbow, and wrist, to make more complex movements and better target the area and better avoid non-targeted areas. This technology has the accuracy of less than a millimeter, or the size of a hair.

The computer guidance system on the CyberKnife allows us to do inverse planning of the radiation treatment. We tell it what doses we want to give and what areas to target and the computer comes up with different angles that no human could generate, automatically limiting radiation doses to the surrounding anatomy.

Tiny marker seeds are inserted near the lumpectomy site and during the treatment two imagers track these seeds. They function like eyes and keep the robotic arm on target to an accuracy of a millimeter while the patient breathes, moves and coughs.
The CyberKnife technology allows fully intelligent treatment of the lumpectomy cavity after breast conservation surgery, enabling what historically took 6-7 weeks of daily radiation to be delivered in 5 outpatient visits.

In 2011, here at NYU Winthrop Hospital, we started a clinical research project looking at treating selected patients with early stage breast cancer on our CyberKnife. With patients now out over 6 years, we have cured over 98% of our patients, which is better than any reported radiation treatment published. This data and our outcomes, combined with data from our colleagues at the Swedish Medical Center, was be presented at the prestigious American Society of Radiation Oncology Meeting (ASTRO) in San Diego this fall.

Accelerated Radiation Programs

For those patients who are not candidates for CyberKnife, accelerated radiation, also called hypofractionation, is still an option. Dr. Timothy Whelan, who was a visiting Canadian lecturer at the Winthrop Breast Seminar last fall has published long-term results on shortening standard whole-breast radiation from 5 weeks to 22 days. At Winthrop, we offer this approach to many of our patients with excellent results. This shortened treatment time frame is much more convenient for patients, and allows them to get back to their families quicker.

Prone Breast Boards

At NYU Winthrop Hospital, we recently began treating select patients in a prone, or face-down, position using a dedicated prone breast board designed specifically for this treatment.

Historically, breast radiation was delivered with patients lying on their backs. Larger breasts would lay flat and spread out, creating a more challenging target for radiation machines and causing the radiation to travel longer distances. By lying face-down, breasts now hang into space, offer a narrower target, and move off the chest wall. Not only does this make sure the radiation delivery is more even, but less radiation reaches the lungs and heart.

The prone breast board enables certain fuller-figured patients to have more uniform doses of radiation reducing radiation “hot spots,” areas that receive too much radiation, often at the edge of the breast. These hot spots can impair the cosmetic side of the healing process, by making those spots on the breast denser or even shrink.

As cancer treatment options constantly evolving, we will have access to new research that will further help our patients and help educate people in our surrounding communities. As a physician and member of The Maurer Foundation Medical Advisory Council, I thank you so much for spending time in reading and for the privilege of entrusting us with your care and education on breast health.