Brachytherapy: Frequently Asked Questions
What are the advantages of seed implantation over other treatments?
There are several advantages of seed implantation over other types of treatment for prostate cancer, including radical prostatectomy and external beam radiation. 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.
A radical prostatectomy, which is removal of the entire prostate gland, often requires a 2-3 day hospital stay and several weeks of recovery at home. Patients treated with external beam radiation require 6-8 weeks of treatment every day at a radiation oncology center.
How do stage, grade and PSA level determine my eligibility?
Men who are candidates for seed implantation have early stage disease, a Gleason score (grade) of 7 or less, and a PSA reading of 10 or less.
The stage of your cancer is a determination of how advanced it is. Prostate cancer is defined by the “TNM” staging system. “T” stands for tumor, “N” for nodes and “M” for metastasis or spread of the cancer. Tumor stages range from T1-T4 and may have further designations within each numerical category, such as T3a. A stage of T1 or T2 is an early form of cancer, meaning that it has not spread outside of the prostate gland and would make one eligible for seed implantation therapy, if the grade and PSA readings also were low.
The stage of your cancer is determined by a physical exam and a digital rectal exam. It also can be determined by an ultrasound exam, a biopsy, bone scan or magnetic resonance imaging (MRI).
The grade of cancer is called the Gleason score, named after the physician who developed it. The grade of cancer is a designation of how aggressive it is based on how fast the tumor cells are growing. The grade ranges from 2-10, with a higher number designating a more aggressive form of cancer, which may have spread or has a high likelihood of spreading outside of the prostate gland. A determination of grade is made from a biopsy sample.
Prostate specific antigen (PSA) is a protein found in the blood that is produced by both normal and cancerous prostate cells. A higher PSA reading may mean that cancer has spread outside of the prostate gland, while a lower number is a sign of slower cancer growth. Your PSA reading is determined by a blood test.
What type of radiation do the seeds contain?
The seeds contain low energy radiation, meaning that the dose of 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.
Iodine 125 releases 90 percent of its energy over a period of 6 months, while Palladium 103 releases 90 percent of its energy within two months. Because one emits most of its strength over a shorter period of time does not mean that it is a better therapy than the other.
Am I radioactive? Is my semen radioactive?
The answer to both of these questions is 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.
Do seeds move to other parts of the body?
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 procedure to check for this occurrence.
Can a seed be passed in urine or in semen?
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.
Are the seeds ever taken out ?
No, the seeds, which lose all of their radioactivity within a year of implantation, remain in the prostate during your lifetime.
How will I feel right after the procedure?
Because seed implantation is a minimally invasive procedure usually performed with a spinal anesthetic, your recovery time will be quicker than if you had undergone an “open” procedure under a general anesthetic. You will be able to leave the hospital the same day.
There may be some discomfort for about a week following your procedure. You may have some pain in the perineal area and may have red-brown discoloration of your urine. A large percentage of patients develop obstructive voiding symptoms, which may include difficulty initiating the urinary stream, maintaining a strong stream or emptying the bladder.
Medication is used to attempt to prevent this side effect, although approximately 10 percent of men require temporary or long-term catheterization until prostatic swelling subsides.
Are seed implants successful?
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 7. 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.
Would I ever be a candidate for a second seed implantation procedure?
Not at the present time. Patients have this procedure only once.