During prostate brachytherapy, physicians implant radioactive “seeds” into the prostate. The seeds deliver a high dose of radiation to the tumor while sparing the surrounding non-cancerous tissues.
Virginia Mason Franciscan Health’s team uses an advanced technique called “real-time dosimetry prostate brachytherapy,” enabling us to place radioactive seeds directly into the prostate with millimeter accuracy.
Physicians use a digital system to precisely track the position of each seed, ensuring proper radiation dose within the prostate. This technology also helps physicians avoid placing the seeds near normal tissues such as the those in the bladder, urethra and rectum, thus minimizing toxicity.
Patients generally undergo spinal anesthesia for this procedure, although general anesthesia also can be used. Needles are placed through the skin of the perineum (the space between the anus and scrotum) and into the prostate. An ultrasound probe in the rectum helps guide the needles into their proper position. The seeds are then placed into the prostate through each needle. As each needle is withdrawn, it leaves behind a row of seeds.
The Iodine-125 radioactive seeds have a half-life of two months. The Palladium-103 radioactive seeds have a half-life of 17 days. After about five half-lives, all radioactivity is gone. The amount of radioactivity that escapes the body is exceedingly small. As a safety precaution, however, we recommend that small children and pregnant women do not sit on or next to the patient for two months. Patients often experience temporary difficulty with urination after brachytherapy. Medications (Flomax®, Hytrin®, Cardura®) are provided to alleviate symptoms.
If you would like to learn more about brachytherapy at Virginia Mason, call our specialists at 206-583-2282.
Patients may have some discomfort in the perineal area for a few days after the procedure. They also may develop some mild urinary obstructive symptoms (mainly frequency and urgency), which could last four to six weeks. Lasting problems such as urinary incontinence or proctitis (inflammation of the rectum) are rare. Impotence can develop in patients, although there are medications that are often helpful in this situation.
Rates of incontinence and impotence are lower with seed implantation. Additionally, because seed implantation is an outpatient procedure, your recovery time is quicker. You will leave the hospital on the same day as your treatment and can be back at work or performing your normal daily activities 2-3 days later.
Men who are candidates for seed implantation have early stage disease, a Gleason score (grade) of seven or less, and a PSA reading of 10 or less.
The seeds contain low-energy radiation, meaning that the radiation stays within the prostate gland and some adjacent tissue. Depending on your Gleason score, one of two isotopes may be used: Iodine 125 or Palladium 103. Patients with low to moderate Gleason scores (2-6) normally have Iodine 125, and those with higher scores (7-10) receive Palladium 103.
No. The radiation from the seeds remains primarily in the prostate gland. However, because some risk cannot be completely ruled out, you will be advised to avoid close contact with children under the age of two and with pregnant women for the first 1-2 months following your procedure.
Because radiation therapy is non-surgical, it does not cause immediate damage to erectile function. However, it may have long-term effects on a patient’s sexual function, especially if they have other conditions such as diabetes. Talk to your doctor about how this treatment may affect your sexual function.
In rare instances, a seed can migrate to the lungs. This occurs when a seed is injected into a large vein near the prostate gland and then travels in the bloodstream to the lungs. It is not a cause for concern, but your doctor will have you undergo a chest x-ray right after your seed implantation to ensure this has not happened.
In very rare instances, a seed may be passed in urine or during sex. If this were to occur, it would happen soon after your treatment. To help avoid a seed from being passed in semen, you will be advised to masturbate several times before having sex with your partner. The seed is not a danger to your partner.
No, the seeds, which lose all of their radioactivity within a year of implantation, remain in the prostate.
The best results with seed implantation are seen in patients whose cancer is confined to the prostate and who have a tumor grade less than seven. This therapy is often effective in terms of PSA recurrence for at least nine to ten years, which among cancer clinicians and researchers, is considered a successful treatment.
In patients who have had seed implants and/or external beam radiation treatment, the cancer cells are not killed instantly as they would be when the prostate gland is removed during surgery. Instead, the cells die over time as the effect of the radiation interferes with the tumor cells’ ability to grow. Men who have had this type of treatment may find that their PSA levels gradually fall off as the effect of the radiation begins to take hold.
Your remaining healthy prostate cells will continue to produce PSA, so a PSA reading following your treatment should not be cause for concern. Your doctor will discuss this issue with you in more detail and will answer questions about whether seed implantation is right for you given your individual circumstances.
Not at the present time. Patients have this procedure only once.
If you would like to learn more about brachytherapy at Virginia Mason Franciscan Health, call our specialists at 206-583-2282.