For prostate cancer conventional brachytherapy, tiny implants or “seeds” are implanted directly into the prostate where they remain permanently. For a set amount of time, these seeds are radioactive and deliver radiation to the prostate, hopefully eliminating any nearby cancerous tissue.
With high-dose rate (HDR) brachytherapy, the same idea is at work. Tiny implantable radioactive sources are used to deliver radiation from within the prostate itself. The difference is that HDR brachytherapy uses radioactive sources of very high energy that can deliver adequate amounts of radiation to the prostate in a short amount of time.
How Is HDR Brachytherapy Done?
HDR brachytherapy uses very high energy radioactive sources (often straw-like in shape) which are inserted into the prostate and then withdrawn again a few minutes later. Several radioactive sources are inserted, one at a time, during a treatment session.
What Are the Advantages of HDR Brachytherapy Over Conventional Brachytherapy?
- There is no required hospital stay. A short hospital stay is often required with conventional implantable seed brachytherapy. HDR brachytherapy is completed over a few outpatient visits.
- There is no radiation exposure to other people. With conventional implantable seed brachytherapy, the radioactive seeds remain in place permanently. They only emit radiation for a number of days after implantation, but, the time you spend around other people (especially small children or pregnant women) may need to be limited during this time. With HDR brachytherapy, the radioactive sources are inserted and withdrawn during the treatment session, thus you carry no radioactivity with you when you leave.
- There is no shifting of seeds within the prostate. Permanently implanted seeds may shift or migrate within the prostate. This is usually not a significant issue, but it can result in some prostate tissue not receiving the appropriate radiation dose or tissue that was not intended to be treated receiving too much dose. With HDR brachytherapy, this complication can be reduced.
What Are Possible Disadvantages?
The biggest disadvantage to HDR brachytherapy is that it has not been as well-studied as conventional brachytherapy. Research is continually being done that looks at the effectiveness, rate of complications, and long-term outcomes of patients treated with HDR brachytherapy, but there is far more information about the effectiveness and safety of conventional brachytherapy.
Additionally, HDR brachytherapy is not available at all hospitals or radiation treatment centers.