Hello. I am Dr Gerald Chodak for Medscape. Today, I want to talk about high-dose-rate temporary brachytherapy (HDRTB) for men with high-risk prostate cancer.
I came across an article on Prostate Cancer Infolink that cited three randomized trials reported in 2005, 2012, and 2013.[1,2,3] In all three studies, patients received either intensity-modulated radiation therapy (IMRT) alone or IMRT plus HDRTB.
Each study reported an improvement in biochemical relapse rates with the combination therapy compared with monotherapy. The question is, how does this fit in the overall management of high-risk disease?
We know that men would benefit from a combination of IMRT plus androgen deprivation therapy (ADT). One problem found in these randomized trials is that ADT was not a routine part of the randomization schedule. Some men received it, some men didn't, but without randomization, the overall findings are compromised.
For at least one of the studies, the amount of radiation used was lower than the standard amount recommended today. We know that 66 Gy is inferior to 76, 78 or 80 Gy; these doses lead to better outcomes for men receiving this therapy.
Another question is, how does this treatment compare with either ADT plus radiation alone or even with the combination of permanent brachytherapy?
My reason for hesitation in using HDRTB is that it's not the most convenient patient treatment. Patients have to come in, get anesthetized, and have catheters placed. This means they are required to stay overnight until the two treatments are completed. They can't lie on their backs while they are waiting for the second treatment, and have to go in and out of the radiology suite. So, one could strongly argue that other methods, including permanent brachytherapy, are more convenient for patients.
Another factor is overall toxicity. At least one of the studies reports an incidence of impotence at about 25%, and one would expect impotence to be rather high with this combination therapy.
At this time, I don't believe we have good enough information to tell us where the combination of HDRTB plus IMRT fits in the overall management of high-risk disease. One could argue that the combination of external-beam radiation plus ADT may still be the best way to go in terms of balancing convenience and side effects.
We need better data from a randomized controlled trial looking at survival as the outcome, because we know from other radiation therapies that biochemical failure rates and survival don't always match.
Although not the most convenient for patients, I still think HDRTB is an interesting therapy. But its real role in the management of high-risk disease is still unclear.
I look forward to your comments. Thank you.
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Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: High-Dose-Rate Brachytherapy in Prostate Cancer: What Role? - Medscape - Oct 16, 2015.