Women with early stage breast cancer increasingly choose to treat the cancer and save their breast. Breast conservation therapy (BCT) starts with the surgical removal of cancerous tissue in a procedure known as lumpectomy. Lumpectomy is followed by daily sessions of radiation therapy to the whole breast for six weeks. Whole breast irradiation (WBI) is widely accepted as the “gold standard” for breast radiotherapy based on over three decades of experience. The BCT protocol also requires additional localized radiation, known as the “boost” dose, aimed only at the tissue surrounding the tumor bed.
The combination of surgery and completion of radiation therapy has been effective in preventing cancer recurrence. Numerous studies show that women with early stage disease have a clear option to preserve the breast and fight off the cancer.
The full course of radiation therapy includes a “boost” dose solely for the breast tissue around the surgical site. This tissue is believed to contain pre-cancerous cells that, if left alone, may cause cancer to return. Numerous studies have shown the contribution of this all-important boost dose for preventing recurrence 1,2 .
Today, the boost dose is aimed at the surgical site mainly by using the surgical scar left on the skin. It is well known that the incision site is primarily chosen to minimize the visibility of the surgical scar and in most cases does not provide a good reference point for the location of the lumpectomy, and is unrelated to its shape and size. In fact, recent reports 3 indicate that in more than 50% of cases analyzed, the boost dose which is aimed via the surgical scar, misses the intended target.
Clearly, methods that direct the boost dose to the target tissue and control both the delivery process and dose quality are important in preventing breast cancer recurrence.
AccuBoost is the latest innovation in breast radiotherapy that achieves the goal of targeting the boost dose to the lumpectomy cavity margin – the tissue that is the most likely site of future recurrence. The AccuBoost design combines a non-invasive method of delivering a well focused beam with the power of real-time image guidance to target the radiation dose accurately and reliably to the surgical excision site (target tissue). Additionally,AccuBoost controls unintentional exposure to otherwise healthy tissue and minimizes radiation-related side effects.
AccuBoost uses applicators placed on the x-ray imaging paddles that are used to immobilize and image the breast (figure 1). The applicators receive a temporary radioactive source from a computer controlled afterloader. The applicator, similar to a flashlight, delivers a beam of penetrating radiation to the breast tissue that lies directly in front (figure 2 & 3).
By properly imaging the surgical site and positioning the applicator at various angles around the breast (figure 4) a therapeutic dose is accumulated in the target tissue without over-exposing the skin and intervening tissue. AccuBoost minimizes exposure of the neighboring organs and reduces radiation related side effects.
The Importance of IGRT In the AccuBoost design, the radiographic imaging equipment and the radiation delivery hardware share a common platform making dose targeting accurate and eliminating daily patient positioning “guess-work”. The real-time image guided radiation therapy (IGRT) feature of AccuBoost allows exact targeting of the tissue giving rise to the AccuBoost slogan: “You see what you treat and you treat what you see.”
The AccuBoost system records both the initial targeting and the therapeutic dose. The dose map is archived and can be used for corrective action during the course of radiotherapy, if necessary, and for future review.
Q. Why breast conservation therapy?
A. Numerous published reports indicate that patients with
early stage breast cancer who choose the lumpectomy
option followed by a full course of radiation therapy that
includes a boost dose, have as good a chance as those
electing mastectomy for cancer free survival while
preserving their breast.
Q. Why is a “boost” dose necessary?
A. The boost dose is an important ingredient of the full course
of radiation therapy and is delivered to the tissue adjacent
to the surgical excision site, a region from which most
recurrences originate. The added boost dose to the surgical
margin has been shown to provide additional protection
against recurrence.
Q. What makes AccuBoost unique from other boost doses?
A. The AccuBoost therapy is the latest innovation in using
real-time imaging techniques to accurately target the boost
dose to the intended site. In addition, the AccuBoost design
delivers a focused (conformal) dose only to the target
tissue, sparing unintended exposure to healthy tissue.
Q. Why is AccuBoost therapy the right choice?
A. The AccuBoost therapy is a more accurate design for
targeting the dose and a highly reliable approach for
delivering focused and uniform radiation to the surgical
margin.AccuBoost is the scientific method for concentrating
the radiation to the required site with minimal exposure
to surrounding healthy tissue and neighboring organs. You
should ask your radiation oncologist about the benefits
of AccuBoost.
Q. What are the side effects of this treatment?
A. AccuBoost has been designed and tested to reduce
radiation related side effects. The uniform and focused field
minimizes radiation related complications. The non-invasive
nature of the AccuBoost procedure eliminates infection and
drainage issues associated with invasive procedures.
Q. Will health insurance cover the cost?
A. Radiation boost and image guidance to target the dose are
accepted procedures for the treatment of breast cancer
and are covered by most plans. Specific coverage for the
AccuBoost procedure will depend on your individual
healthcare plan
