Used to treat more than one million patients a year, radiation therapy alters how a cell grows and divides in the body. Radiation therapy attacks fast-growing cancer cells, but can also affect normal cells, which can result in side effects. Effective treatment involves the balance of destroying cancer cells and preserving cells of healthy tissue.

How is radiation therapy delivered?

There are two primary means of delivering radiation therapy: externally and internally. External radiation therapy delivers a beam of high-energy X-rays to the location of the patient's tumor. The beam is generated outside the patient. These X-rays can destroy the cancer cells. Careful treatment planning reduces, but does not eliminate, exposure to surrounding healthy tissues. Internal radiation therapy, known as brachytherapy, means short-distance therapy. By delivering a higher dose of radiation directly into a targeted area, brachytherapy minimizes dose to healthy surrounding tissues.

What is brachytherapy?

Brachytherapy is radiation therapy delivered over a short distance. Instead of using external radiation from outside the body, brachytherapy delivers the dose directly inside the body where the cancer was removed or next to the existing tumor, thus sparing healthy surrounding tissues.

What is Electronic Brachytherapy – eBx®?

Electronic Brachytherapy (eBx®) is electronically generated radiation delivered near the tumor site. Instead of using external radiation from outside the body, brachytherapy delivers the dose directly inside the body where the cancer was removed or next to the existing tumor. The goal is to direct the radiation dose to the cancerous area, so the patient receives less radiation to critical organs and healthy tissue.

What is breast-conserving therapy?

A mastectomy is surgery to remove the breast affected by cancer. In contrast, breast-conserving therapy, also known as a lumpectomy, involves surgery to remove a breast cancer tumor along with a small amount of surrounding tissue while preserving most of the breast. It is combined with axillary lymph node removal or sentinel node biopsy to determine if the lymph nodes located in the armpit may be affected by cancer. Breast-conserving therapy may be an option for patients with early stage breast cancer. In breast-conserving therapy, treatment includes the addition of radiation therapy to the remaining tissue surrounding the surgical cavity.

What is Intraoperative Radiation Therapy (IORT) for Breast Cancer?

IORT is a technique where radiation is given in a single dose at the time of lumpectomy surgery. Immediately after the tumor is removed, a small, inflatable balloon is placed into the breast cavity. Radiation therapy utilizing the Xoft® Electronic Brachytherapy System®  is then delivered. This radiation therapy takes place in as little as eight minutes during surgery. Once the radiation therapy is finished, the doctor removes the balloon, closes the tumor cavity, and your treatment is complete.

Are there clinical advantages to using eBx® to deliver IORT?

You should discuss Intraoperative Radiation Therapy (IORT), and all of your treatment options, with your physician. Some clinical advantages of eBx® to deliver IORT for early stage breast cancer are:

• IORT provides a simple one step treatment without the hassle of radiation delivered over 6-7 weeks. For you, this means less travel, fewer days off work, less emotional stress and fewer appointments.
• Radiation is delivered directly to the tumor bed and tissue most likely to harbor microscopic cancer cells
• Accurate delivery of the radiation is possible because the doctor knows precisely where the tumor was located 1,2
• If reconstruction is a consideration it can be completed during your surgery
• Less radiation is delivered to surrounding healthy organs and tissue 3

What is Accelerated Partial Breast Irradiation (APBI)?

APBI is used after breast conserving surgery and differs from external beam radiation therapy in two main ways. First, APBI is a type of brachytherapy which reduces the treatment area from the entire breast to the area of the breast where the tumor was removed. This is the part of the breast where most cancers are likely to recur. Second, it shortens the treatment time from seven weeks to five days. Since the duration of treatment is shorter, radiation is delivered in fewer sessions at larger doses.

Are there clinical advantages to using eBx® to deliver APBI?

Utilizing eBx® for APBI has important clinical advantages. First, eBx® eliminates the need for heavily shielded environments, which gives radiation oncologists the flexibility to deliver therapy in a broader range of clinical settings. Use of the Xoft System also reduces the total time required for radiation therapy for early stage breast cancer from seven weeks (for external radiation therapy) to five days. As a result, patients will benefit from therapy that is delivered more easily and conveniently.

How is eBx® used to treat skin cancer?

Surgical removal of skin cancer is the most common treatment, but in patients with Non-Melanoma Skin Cancer (NMSC) such as basal cell or squamous cell, eBx® can be an alternative with excellent cosmetic results. During eBx® treatment, a surface applicator is positioned over the skin cancer and connected to the Axxent® Controller. A miniaturized X-ray source is placed in the applicator and activated to deliver radiation for a few minutes. At the completion of the treatment, the X-ray source is turned off. Each treatment regimen and prescription will depend on tumor size, type, depth, patient age, prior treatments and other criteria.

What are the advantages of eBx® for skin cancer?

Radiotherapy can be an excellent alternative or addition to surgery:

• for patients with cosmetically sensitive lesions not interested in surgery;
• when restoration of larger lesions on lips or ears is difficult or impossible for necessary function (wearing glasses etc.);
• to reduce the risk of recurrence if there are remaining cancer cells;
• in cases where surgery is not appropriate (e.g., blood-thinning medication).

How is eBx® used to treat gynecological cancers?

eBx® for endometrial cancer delivers localized radiation treatment through a cylinder-shaped vaginal applicator. While each clinical setting will have a different treatment routine, the following steps are typically included in the procedure:

• Insertion of a vaginal applicator, the process should not be painful, but you may feel some pressure
• Radiation technician may take a CT or X-ray image to verify the position of the applicator
• Your Physician will determine how much radiation is needed, treatment may take approximately 10 minutes

What are the advantages of eBx® vaginal brachytherapy?

• Reduced radiation dose to healthy tissue, such as bladder and rectum, as compared to radioactive isotope treatments.3
• Patients do not need to be isolated from the physician during radiation treatment due to the safety features of the eBx® system.

References

1. Ivanov O, Dickler A, Lum BYF, et al. Twelve-Month Follow-Up Results of a Trial Utilizing Axxent Electronic Brachytherapy to Deliver Intraoperative Radiation Therapy for Early-Stage Breast Cancer. Ann Surg Oncol 2010; 18: 453-8.
2. Dickler A, Ivanov O, and Francescatti D. Intraoperative radiation therapy in the treatment of early-stage breast cancer utilizing Xoft® Axxent electronic brachytherapy. World J Surg Oncol 2009; 7: 24.
3. Dickler, et al. "A Dosimetric comparison of MammoSite high dose rate brachytherapy and Xoft® Axxent electronic brachytherapy," Brachytherapy (6) 2007, 164–168. "A Dosimetric comparison of Xoft® Axxent Electronic Brachytherapy and Ir-192 HDR brachytherapy in the treatment of endometrial cancer," Brachytherapy (7) 2008, 154