Brachytherapy for Early-Stage Breast Cancer

Brachytherapy is a type of cancer treatment, also called internal radiation therapy, that involves placing a sealed radioactive source in or near a tumor to destroy the cancer cells. It is used to treat many different types of cancer but can be used in breast cancer to kill cancer cells after a lumpectomy. It’s also used to reduce the size of a tumor before breast cancer surgery or as palliative treatment to reduce pain or bleeding in advanced or inoperable disease.

Brachytherapy is used to treat early-stage breast cancers that have not spread (metastasized) to other parts of the body. The treatment can be delivered in different ways and is often combined with conventional external beam radiation therapy (EBRT).

Purpose of Treatment

EBRT is the standard of care for people who have undergone a lumpectomy or mastectomy. Breast brachytherapy can help support EBRT by “boosting” the response rate and improving outcomes. In recent years, high-dose brachytherapy has been used as a standalone treatment of early-stage cancer, a procedure referred to as accelerated partial breast irradiation (ABPI).

Brachytherapy is also sometimes used in neoadjuvant therapy, a form of treatment designed to shrink a tumor before surgery. Doing so can reduce the risk of cancer recurrence by decreasing the tumor margins (the transitional areas between normal and cancerous tissue), where cancer cells hide.

Brachytherapy Types

Both the implants and implantation methods used in brachytherapy can vary by cancer stage and type. The implants may be temporary or permanent and vary in size and radioactive strength. Depending on the procedure, the specialist (known as a radiation oncologist) may use radioactive seeds, pellets, capsules, ribbons, tubes, or balloons.

There are five methods used to deliver breast brachytherapy, each of which has specific purposes and indications:

• Interstitial breast brachytherapy involves the placement of several flexible tubes (catheters) in the breast tissue through which a radiation source is placed.
• Intracavity breast brachytherapy, also known as balloon brachytherapy, is used after a lumpectomy to deliver radiation to the breast cavity via an inflatable balloon.
• Intraoperative radiation therapy delivers localized radiation during the lumpectomy via a cone-shaped applicator and a radiation emitter.
• Permanent breast seed implant (PBSI) involves the permanent implantation of low-dose radioactive seeds to prevent cancer recurrence in someone with early-stage breast cancer.
• Non-invasive breast brachytherapy (NIBB) is a newer procedure that doesn’t require catheters or implantation but instead delivers a concentrated beam of radiation while the breast is compressed during a mammogram.

Dosage

The type of radioactive material used in brachytherapy (typically iodine, palladium, cesium, or iridium) varies by treatment type. The material, called the source, is encapsulated in a metal shell that controls how much radiation is emitted.

The length of time an implant is left in place depends on the type of brachytherapy used. This is directed by the dose rate, described in units called Grays per hour (Gy/hr). With breast cancer, there are five possible dose rates:

• Ultra-low-dose rate (ULDR) brachytherapy involves seeds or pellets that emit radiation at 0.1 to 0.3 Grays per hour.
• Low-dose rate (LDR) brachytherapy involves implants that emit radiation at 2 Grays per hour.
• Medium-dose rate (MDR) brachytherapy emits radiation at 2 to 12 Grays per hour.
• High-dose rate (HDR) brachytherapy emits radiation at greater than 12 Grays per hour.
• Pulse-dose rate (PDR) brachytherapy involves short pulses of high-dose radiation, typically once per hour, to enhance the effectiveness of LDR.

Higher dose rates are associated with shorter treatment times, and vice versa. With HDR brachytherapy, the implants are placed for only a few minutes at a time and then removed, with additional treatments given every several days or weeks. With LDR brachytherapy, the radioactive source may be left in for one or several days.

LDR and MDR brachytherapy are typically used to “boost” EBRT following surgery, while ULDR brachytherapy is reserved for permanent implants, including PBSI.

PDR brachytherapy is a more recent innovation that combines the efficacy of HDR technology with the improved tissue safety of LDR brachytherapy.

The Procedure

Brachytherapy requires a treatment team, which may include a radiation oncologist, dosimetrist, radiation therapist, nurse, and occasionally a surgeon. 

With the exception of NIBB, breast brachytherapy will involve some sort of invasive procedure. The radioactive source may be delivered using a needle-like applicator, via one or more temporary catheters, or during breast surgery.

The implantation is usually performed in a hospital operating room specially designed to keep radiation from seeping out. Depending on the procedure, you will either be given local anesthesia to numb the general area or general anesthesia to put you to sleep.

As with any procedure involving anesthesia, you will be given specific instructions on when to stop eating or drinking before the procedure.

During the Procedure

Breast brachytherapy requires an imaging tool, such as an X-ray, ultrasound, or computed tomography (CT), to direct the placement of the radioactive source. Once the coordinates are determined, one or more sources are strategically placed to target cancer but spare the surrounding cells.

The various procedures can be broadly described as follows:

• With interstitial brachytherapy, several catheters are placed so that radioactive pellets can be readily inserted and removed. This is most often done one to two weeks after surgery. HDR brachytherapy is delivered in a series of 10- to 20-minute sessions. LDR brachytherapy is delivered continuously over one to two days.
• With intracavity brachytherapy, a single catheter with an inflatable balloon is inserted into the breast cavity following a lumpectomy. Tiny radioactive pellets are then fed into the balloon. Sometimes the catheter is placed during surgery and filled with pellets in the oncologist’s office several days later.
• With intraoperative brachytherapy, the radiation is delivered into the breast cavity via a targeted emitter immediately following the lumpectomy. The treatment is usually completed in less than an hour.
• With PBSI, the radioactive seeds are individually placed with a percutaneous applicator that inserts the seeds directly through the skin.

After the Procedure

After the brachytherapy procedure is finished, you are led to the recovery room and monitored from anywhere from 30 minutes to several hours. You will likely feel localized pain around the implantation site. You may also have swelling, redness, and bruising. Side effects from the anesthesia may include sleepiness, confusion, and nausea.

Some radioactive implants may be left in place from one to several days. If so, you will probably need to remain in the hospital during treatment, often in a special radiation-proof room. Larger implants may require you to stay in bed without moving.

If you have been given permanent brachytherapy seeds, you can usually go home the same day. The radiation will wear off in a couple of weeks, and the seeds will slowly deteriorate over time.

Tips for Multiple Procedures

If multiple treatments are required, you will need to care for the breast catheters until the treatment is completed. You will still be able to perform most daily routines and drive yourself to and from the healthcare provider’s office.

There are several precautions to take to help reduce the risk of injury or infection. These can include:

• Always wear a bra to keep the catheters securely in place.
• Do not shower. Instead, take a sponge bath and wash your hair over the sink.
• Avoid getting the treated breast wet.
• Clean the catheter site daily with a solution made with equal parts water and hydrogen peroxide. Apply a thin layer of antibiotic cream afterward.
• Do not pull off any Steri-Strip tapes that cover incisions on the breast or armpit. Let them fall off on their own.

Once you have finished treatment, the catheters will be removed. Additional evaluations to assess your response should be scheduled.

Side Effects

Beyond the effects of the surgery itself, brachytherapy can cause both acute and long-term side effects. These tend to be far less severe than with EBRT.

Fatigue is the most common short-term side effect lasting for one or several days. Less commonly, there may be a generalized soreness in the treated breast. A mild pain reliever like Advil (ibuprofen), Aleve (naproxen), or Tylenol (acetaminophen) can usually ease breast tenderness.

In some cases, the implantation of the catheter can cause a seroma, a pocket of fluid beneath the skin that may require drainage with a needle as well as oral antibiotics.

Long-term side effects are less common but may include a change in skin texture and color, skin dryness, and a loss of hair under the arm. Moisturizing the skin can usually help.

You may also experience the swelling of an arm if brachytherapy was performed near the axillary lymph nodes in the armpit. Known as lymphedema, the condition will usually be mild and resolve on its own without treatment. Call your healthcare provider if the condition persists or worsen.

Cost

The cost of treating breast cancer with brachytherapy can vary greatly. One study found that whole-breast brachytherapy was less expensive overall (and more effective) than the older approach of brachytherapy-based accelerated partial breast radiotherapy.

The findings suggested that one year of the whole-breast approach cost between $6,375 and $19,917, which could save between $4,886 and $4,803 compared to the partial-breast treatment.

It’s worth noting that most major insurance companies cover at least part of the cost for brachytherapy.

Contraindications

Breast brachytherapy is not for everyone. Although most people with breast cancer will benefit from lumpectomy and EBRT, only a subgroup are appropriate candidates for breast brachytherapy. Some of the contraindications include:

• Pregnancy
• Stage 3 or stage 4 breast cancer
• Having bilateral breast cancer (cancer in both breasts)
• Having had cancer in the opposite breast
• Having had other cancers (with the exception of skin cancer and certain gynecological cancers)
• Paget’s disease, which disrupts the replacement of bone tissue
• Certain connective tissue or collagen disorders

Brachytherapy for Other Types of Cancer

In addition to treating breast cancer, brachytherapy is used on different types, including head and neck, eye, and prostate. Brachytherapy is also an effective treatment option for those with cervical cancer, which uses intracavity brachytherapy and involves radiation being placed in the vagina as a treatment.

Just like with breast cancer, the success rates of brachytherapy in other types of cancer vary depending on type and severity, but it is generally considered an effective treatment. For example, in cervical cancer, the treatment can achieve control rates of 100% for stage 1, 96% for stage 2, and 86% for stage 3 cancers.

Summary

Brachytherapy can be used in early-stage breast cancers as part of a comprehensive treatment plan. While it is not a first-line treatment, it can help boost the effectiveness of EBRT.