THE STAGING GUIDE VIDEO SERIES | TRANSCRIPTION:
Hi, I’m Dr. Scholz. Let’s talk about prostate cancer.
So in this video we are going to cover an important treatment for intermediate risk or Teal prostate cancer called High Dose Rate Temporary Seeds or “HDR.” Seed implantation comes in two forms. You can look at our video on permanent seeds, which is the most popular type of seed implant. In this particular type of seed implant, the seeds are put in in the hospital and then removed before you go home. Thus, the designation of temporary seeds. Whenever you’re thinking about treatment with seed implants, whether it be permanent or temporary, you need to seek out the best practitioner. These are skilled procedures—just like a good operation, a good surgeon is needed—for seed implants you need an experienced and well-trained seed implanter.
I’m often asked should someone do temporary seeds or permanent seeds. All things being equal, the skill level of that doctor is more important than whether you do permanent or temporary seeds. Permanent seeds are more convenient and therefore tend to be more popular. That doesn’t mean that they work better or worse. When considering doing a seed implant, the question always comes up as to whether or not you should add external beam radiation, so called IMRT or intensity modulated radiation. Typically, if you’ve looked at the PCRI staging program, men who are getting staged as Basic-Teal can have a seed implant without any external beam radiation. Men who are in the category of High-Teal should consider a seed implant in combination with external beam radiation. This is true with permanent seeds or temporary seeds.
So we’ve talked about temporary seeds; what actually are temporary seeds? Temporary seeds use catheters, and I’m not talking about urinary catheters; I’m talking about little hollow tubes that are placed while the patient is in the hospital through the skin of the perineum (this is the skin between the scrotum and the anus) and left in place for at least six hours and sometimes as long as twenty-four hours. While the patient is in the hospital a very high intensity iridium seed will be placed at the end of the catheter and then slowly pulled back in the area where the prostate is to administer the radiation. Two or three such cycles may done during the hospitalization—perhaps every six to eight hours. That’s the essence of temporary seeds.
The issue with temporary seeds therefore is that you have to be in the hospital and these catheters remain in place throughout the hospitalization so that means the patient has to be semi-immobilized. No one wants the catheter to shift around and create inaccuracies of treatment. So a temporary seed implant is a more complex and involved procedure than a permanent seed implant, and when you compare these two options that could be considered a disadvantage for temporary seeds compared to permanent seeds. So what is the advantage of doing a temporary seed procedure if a permanent seed procedure can be done more conveniently? Probably the one advantage is that because of the very fast delivery of radiation there’s some suggestion, not proof, but some suggestion that the anticancer efficacy may be enhanced to some degree. Another advantage is that because catheters can be placed around the prostate—whereas permanent seeds can only be placed within the prostate—the doctor doing a temporary seed implant can steer the radiation out around the gland more easily. This becomes a real issue if, for example, you want to treat the seminal vesicles—the little rabbit ears at the top of the prostate. It’s much easier to do that with a temporary seed implant than with a permanent seed implant.
Briefly, let’s talk about side-effects. Side-effects of a temporary seed implant are very similar to that of a permanent seed implant. There is a risk of erectile dysfunction. There is a risk of inflammation of the urinary passage through the prostate called the urethra. Inflammation is called urethritis. Short-term urethritis occurs with seed implants and may last from anywhere from three and eight weeks. The problem is that a small percentage can have long-term urethritis which translates into more frequent urination during the day, getting up at night, discomfort with urination. There are treatments for this, and if the treatments were perfect we wouldn’t be discussing it, so some people are left with ongoing symptoms. In a skillfully performed seed implant you’re looking at a risk of maybe 5-15% of such problems like long-term urethritis. A very small percentage of people that have urethritis can develop scarring or stricture, this means that the passageway of urine—of the urethra—is obstructed, and if that occurs (this can also occur with surgery, permanent seed implants, and perhaps less frequently with external beam radiation) the area needs to be stretched out, and in some cases scar tissue doesn’t stretch very well and very rarely it can translate into incontinence. This complication may occur anywhere from 1-3% of the time in men that have this type of treatment.
One issue that comes up is monitoring for a cancer relapse after treatment. When men have surgery, the prostate is removed completely and the PSA should be zero. If there is any detectable PSA that’s a very strong sign the cancer is back. After radiation, be it a seed implant or external beam, the prostate is still in place and will produce some PSA. There’s no absolute threshold of what’s normal and abnormal, but typically a cutoff of a PSA of around 1 can be considered a level for concern if the level for concern if the PSA goes above 1. Another phenomenon is the temporary rise of PSA above 1, perhaps even higher than that, due to delayed inflammation in the prostate called the “PSA bump.” This occurs after high dose rate seeds in as many as 25 or 30% of men. It can occur up to three years after the seed implant is performed creating all kinds of confusion and difficulty in certain cases. When that happens people need to be simply watched closely and try and observe for an erratic pattern of PSA jumping around which is more consistent with inflammation versus a steady incremental unremitting rise of PSA which is more consistent with a cancer relapse.
So in conclusion, seed implants in my opinion should be at the top of the list as a consideration for treatment for therapy for men with Teal. The cure rates are better than the other options and the side-effects are certainly no worse and of course compared to surgery they’re much less. When trying to make a distinction between doing a high dose rate seed implant versus permanent seeds, both of which are good options, I would go with the more experienced practitioner. The inconvenience of going in the hospital for one night or maybe two nights is small compared to the problems that can happen when a seed implant is done unskillfully.
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