Radiation Safety for Internal Radiation Therapy (Brachytherapy)
Internal radiation uses a “source” (implants) that has a radioactive substance in it. These can include a seed, pellet, wire, capsule, needle, or catheter. This radioactive material is put into your body through a needle or a wire. The implants are sealed and tested to ensure that the radioactive material stays in the seed and does not leak into your body. Depending on the type of implant used, your body may give off a small amount of radiation for a period of time.
- Low-dose rate (LDR) or permanent brachytherapy: Implants are placed so that it is highly unlikely that they will move. This is important to ensure that the radiation is delivered to the correct area of the body.
- This type of brachytherapy is often used for prostate and gynecologic cancer treatment.
- High-dose rate (HDR) brachytherapy: The source is put in place for 10-30 minutes and then taken out. The care team will ensure that the source is in the correct position and then properly removed.
- This type of brachytherapy is often used for gynecologic cancers and breast cancer treatment.
Radiation Exposure after Treatment
With LDR brachytherapy there is a low risk of exposure to other people. LDR brachytherapy will slowly stop giving off radiation after a specific amount of time. Your provider will be able to tell you when your permanent implant will stop giving off radiation. In some cases, this treatment is done during a few days stay in the hospital. In that case, your hospital care team will review the precautions they will follow during your treatment.
The radiation only travels a short distance around the implant (the treatment area), but precautions may still need to be taken. These are different for everyone depending on your specific treatment plan. Some precautions may include:
- Remaining in the hospital for a period of time after the implant.
- Limiting visitors during treatment.
- Not visiting or limiting the length of time and frequency you spend with pregnant women.
- Avoiding young children sitting on your lap.
- Avoiding young pets sitting on your lap for long periods of time.
If your implant is temporary (HDR), you will no longer give off radiation once it is removed. No precautions need to be taken once you leave the treatment facility.
Prostate Seed Implants and The Risk to Your Sexual Partner
Prostate cancer brachytherapy is done by implanting seeds into your prostate gland. This is the most common treatment using LDR brachytherapy. There may be extra precautions that you need to take with this type of treatment. Your radiation oncologist will give you specific recommendations and for how long to follow them. They typically include:
- Avoiding sexual intercourse for one to two weeks after getting the implants.
- Using a condom during sexual intercourse in case a seed is passed during ejaculation.
- Avoiding riding a bicycle or motorcycle because the pressure could cause the seeds in your body to move.
Radiation exposure to family and household members after you have received LDR brachytherapy is very low and should not be a concern when considering this type of treatment. The use of brachytherapy is safe, but it is important to follow the guidelines given to you from your care team after treatment.
American Cancer Society. (2019, December 27). Radiation Therapy Safety. https://www.cancer.org/treatment/treatments-and-side-effects/treatment-types/radiation/safety.html
Michalski, J., Mutic, S., Eichling, J., & Ahmed, S. N. (2003). Radiation exposure to family and household members after prostate brachytherapy. International Journal of Radiation Oncology* Biology* Physics, 56(3), 764-768.
Stish, B. J., Davis, B. J., Mynderse, L. A., McLaren, R. H., Deufel, C. L., & Choo, R. (2018). Low dose rate prostate brachytherapy. Translational andrology and urology, 7(3), 341.