savi brachytherapy Use implanted devices that deliver radiation internally. SAVI stands for Structural Adjustment Volume Implant. Brachytherapy is also called internal radiation therapy.
SAVI is commonly used after lumpectomy in patients diagnosed with early-stage breast cancer. This type of brachytherapy differs from external beam radiation, which applies radiation from outside the body and can cause damage to the underlying tissues of the breast, lungs, and chest cavity.
SAVI reduces the treatment time for conventional whole breast irradiation from up to 7 weeks to 1 week or less. This short-course method is called accelerated partial breast irradiation (ABPI).
In studies, ABPI was shown to improve cosmetic outcomes while still being an effective treatment and was generally well tolerated by patients, with patients generally reporting fewer side effects than patients who received whole breast irradiation.
This article will explain when to use SAVI, how it works, and what to expect from the process.
who is this for
The purpose of radiation therapy is to prevent breast cancer from coming back by killing any remaining cancer cells. To protect the breast and spare surrounding tissue, brachytherapy is increasingly used for stage 0, 1, or 2 breast cancer when the tumor is less than 3 centimeters (1.2 inches) in diameter.
Because the volume of the SAVI device is customizable, it can be used to treat cavities of various sizes or shapes after surgery.
how does this work
The SAVI system consists of a tubular applicator (called trocar), a bundle of expandable microcatheters, and a computerized radiation delivery system. The bundled catheter is positioned around the applicator stem like the ribs of an umbrella.
Once the device is inserted through a small incision in the breast, the rod partially retracts, causing the catheter to expand into a spherical shape. The microcatheter is soft and flexible, and conforms to the shape of the surgical cavity, providing a snug fit.
Radiation dose can be individually controlled through each catheter, allowing oncologists to pinpoint precise targeting. Once a round of treatment is complete, the inner catheter can be left in place until the next round.
According to a 2016 study in the journal brachytherapy, SAVI-based APBI achieved four-year survival rates of 92% to 98% among the 250 women studied. Of these, only 2.3% experienced cancer recurrence.
The SAVI device received 510(k) clearance from the U.S. Food and Drug Administration (FDA) in 2006. This classification is used for medical devices that are considered safe and “substantially equivalent” to similar devices currently in use.
It has several advantages over other radiation therapy methods:
- Shorter treatment time (5 to 7 days compared to 5 to 7 days)Aix Full breast irradiation): This means less disruption to your schedule, less travel time and less co-pays.
- Lower radiation levels: With whole breast radiation, healthy cells in the irradiated area are affected along with cancer cells, causing problems such as skin burns and tissue thickening. APBI with SAVI brachytherapy is more precise in its target area, thereby minimizing damage to surrounding tissue.
- Reduce fatigue: Standard radiation can cause fatigue, but with brachytherapy, you should be able to live as normal.
Unlike interstitial brachytherapy, which involves the insertion of multiple tubes (catheters) in and around the tumor, the SAVI system requires only one entry point.
Like other forms of brachytherapy, SAVI-based APBI reduces many of the characteristic risks of external beam radiation. These include skin changes (sometimes permanent), hardening of breast tissue (called radiation fibrosis), spider veins (telangiectasia), changes in breast shape, local nerve damage (brachial plexus), as well as damage to underlying bone and lung tissue.
Long-Term Side Effects of Radiation Therapy
SAVI brachytherapy is a two-part procedure involving the implantation of the SAVI device and the actual radiation therapy. This usually involves a group of providers, including radiation oncologists, dosimetrists, radiation therapists, and nurses.
The SAVI device can be placed in a separate procedure during or after lumpectomy. The latter can be performed as an in-office procedure or as an outpatient clinic.
Before insertion, the breast is evaluated with an ultrasound to determine the size and shape of the surgical cavity. There are four different sizes of implantable devices to choose from.
If the procedure is performed on an outpatient basis, a topical lidocaine anesthetic is used to numb the incision area. A sharp, tubular trocar is then inserted into the breast under ultrasound guidance. Next, the SAVI device is advanced into the trocar and deployed until it fully fits into the space.
After removing the trocar, secure the incision site with a sterile dressing; no sutures (sutures) are required. Only a small bundle of duct ends extend outside the breast.
Once the SAVI device is in place, you will go to your radiation oncologist to begin treatment. Radiation is given twice a day for about five days in a dedicated radiology facility. Some cancers may only require three to four days of treatment; others may require as many as seven.
At this stage, the outer catheter ends are each connected to a machine called a high-dose radiation (HDR) post-loader. The device is programmed to deliver tiny radioactive particles called brachytherapy seeds into each tube. Dosimetrists use laboratory results to determine the appropriate radiation dose, measured in Grays per hour (Gy/hr).
Leave the seeds in place for 10 minutes, then remove. After the dose is complete, the seeds are removed and reinserted six hours later, for a total of two treatments per day.
After the final round of radiation therapy, the oncologist will remove the SAVI device. This can be done in about two minutes with or without lidocaine. Steri-Strip is used to close the incision site. Then put a bandage or dressing on it and you are free to leave. One or more follow-up visits will be scheduled to ensure proper healing of the incision.
Compared to external beam radiation, SAVI brachytherapy has far fewer side effects. Fatigue is a common radiation-related side effect that usually subsides within a few days after treatment is completed.
Other less common side effects include changes in skin tone, dry skin and loss of underarm hair.If the treatment site is near the armpit, the arm may become swollen lymphedema (blocked lymph nodes).
As with any surgical procedure, there is a risk of infection. To avoid this potential problem, follow your healthcare provider’s advice and these tips:
- Put on a bra to hold the catheter end securely in place.
- Do not shower. Take a sponge bath, then wash your hair in the sink.
- Avoid getting your breasts wet.
- Wash the catheter site daily or according to your healthcare provider’s instructions, then apply a thin layer of antibiotic cream.
In rare cases, implantation of the SAVI device results in a seroma, a pocket of fluid under the skin, that may require drainage and a course of oral antibiotics.
Call your healthcare provider right away if you have a high fever, pus-like discharge, and/or persistent or worsening pain, redness, and swelling around the incision site.
As attractive an option as SAVI brachytherapy, it is only indicated for the treatment of early-stage breast cancer. This procedure is best for women over the age of 50 who have a well-defined tumor. Although not completely contraindicated in younger women, SAVI may not be suitable for women under the age of 40.
Some factors that may exclude you from a candidate include:
- Stage 3 breast cancer with lymph node involvement
- Stage 4 breast cancer, in which the cancer has spread (metastasized) to distant organs
- Bilateral breast cancer (bilateral breast cancer)
- have other types of cancer
- Paget’s disease, which causes broken bones
SAVI brachytherapy is often an effective treatment option for patients with early-stage breast cancer. This type of internally delivered radiation generally provides improved treatment outcomes with fewer reported side effects than external whole breast radiation. Always discuss all available treatment options and potential side effects in depth with your healthcare provider to determine the best option for your individual situation.
SAVI brachytherapy is available throughout North America, but not in every cancer center. There may be factors that keep you from receiving treatment, but local availability shouldn’t be one of them.
If you live outside a major urban center and have limited radiation therapy options, you may want to consider traveling for 5 to 7 days of SAVI brachytherapy, rather than whole breast irradiation simply because no other local options are available.
What is Mammosite Breast Radiation Therapy?
Frequently Asked Questions
What does SAVI stand for?
The term SAVI is an acronym for Post-Adjusted Volume Implant. This implantable specialized device is used to deliver internal radiation therapy (brachytherapy). As part of treatment, struts (device parts that can be resized) allow your radiation oncologist to expand the device to fit the breast cavity.
How long does it take to place the SAVI device?
Implantation of the SAVI device is typically performed as an outpatient same-day procedure and usually takes about 20 minutes. The procedure is performed using a small incision placement device under ultrasound guidance.
How does SAVI work?
Although SAVI has a shorter course of treatment and less radiation to surrounding tissue, it has been shown to be effective in treating early-stage breast cancer. This APBI delivery system is generally well tolerated by patients who report side effects such as fatigue less frequently.