What does brachytherapy for breast cancer involve?
There are two types of brachytherapy that can be used to treat breast cancer:
- Low dose rate (LDR) brachytherapy
- High dose rate (HDR) brachytherapy
LDR brachytherapy uses radiation sources that give out a low level of radiation, while HDR sources give out a higher level of radiation. HDR brachytherapy is much more commonly used than LDR brachytherapy.1 Learn about the principles of HDR brachytherapy.
After surgery, radiotherapy is commonly used to kill any remaining cancer cells.1
HDR brachytherapy can be given after the whole breast has been treated using external beam radiotherapy, known as whole breast irradiation (WBI). In this instance, brachytherapy provides a ‘boost’ of radiation just to the area where the tumor was.1
Alternatively, HDR brachytherapy can be used as the sole method of radiotherapy after surgery, known as accelerated partial breast irradiation (APBI). This provides targeted radiation to just the area around where the tumor was and can be completed much more quickly than WBI.1
There are three main stages to the brachytherapy procedure: a) planning, b) treatment delivery and c) post-procedure monitoring.
- The planning stage first involves having a scan, such as an:
- Mammography (X-ray)
- Ultrasound scan;
- Computerised Tomography (CT) scan.
- The scan provides an accurate picture of the tumor and its position. This image helps the doctor calculate how much radiation is needed to treat the cancer and where the radiation should be placed in the breast.
There are two main ways in which the brachytherapy applicators (which will carry the radiation sources) can be placed.
When is it used?
|Interstitial using needles|
|A series of needles (often replaced by softer catheters) are inserted into the breast tissue. This is performed under a general or local anaesthetic to avoid any discomfort.||After whole breast irradiation as a ‘boost’ dose of radiotherapy, or as the sole method of radiotherapy (accelerated partial breast irradiation).|
|Intracavitary using balloon or strut device|
|An inflatable balloon or strut device is placed in the breast. This is done at the time the breast cancer is surgically removed or in the week following surgery. The balloon or strut device is inflated/expanded in the cavity left behind after surgery.||Sometimes after whole breast irradiation as a ‘boost’ dose of radiotherapy, but mostly as the sole method of radiotherapy (accelerated partial breast irradiation).|
The applicators are then attached to a computer controlled machine, known as an afterloader. The afterloader sends a small radiation source down the catheters to the treatment site in the breast and it is left in place for a predetermined period of time.
The computer is programmed to control very accurately where the radiation is delivered and how long it remains in or next to the breast tissue. This ensures that a very precise and accurate dose of radiation is delivered to the tumor. This precision reduces the risk of healthy surrounding tissues or organs being damaged by the radiation.
After the set period of time, the radiation source is transferred back out of the applicator and into the afterloader.
A follow-up appointment will be scheduled a few weeks after the procedure.
This appointment is to check that the treatment is going well and monitor for any possible side effects.
1. Kelley JR et al. In Devlin PM (Ed), Brachytherapy: applications and techniques. Philadelphia, PA, LWW. 2007.
2. Patel RR, Arthur DW. Hematology/Oncology Clinics of North America 2006;20(1):97–118.