Prostate Seed Implantation
Prostate Brachytherapy, also known as a Radioactive Transperineal Prostate Seed Implantation, is another method of delivering radiation using radioactive seeds implanted into the prostate. This form of therapy delivers photon radiation from the “inside-out,” as opposed to the external beam technologies like SBRT or VMAT that delivers radiation from the “outside-in.”
How is the seed implant performed?
Seed implants are performed as an outpatient procedure at either an ARC facility, and ambulatory surgical center (ASC) or even in a hospital setting – but is always an outpatient procedure – i.e. you will go home that same day. The procedure is performed by your Radiation Oncologist (with occasional involvement of a Urologist. When you arrive for your appointment, the nursing staff will make you feel at ease. First, they will see if you have any unanswered questions and prepare any paperwork; next you will meet with the Anesthesiologist to review the anesthesia process and ask any questions. You will be taken to the procedure/operating room where you will be prepared for the procedure and given anesthesia. Once you are comfortably asleep, your Radiation Oncologist will begin the procedure by measuring the exact volume of the prostate in the treatment. Your doctor will then calculate the radiation dose needed based on that volume, utilizing a computerized planning system, which enables a 3-dimensional dose calculation. Once the number of seeds required has been calculated (any can vary from 30 to 100+, depending on the size of the prostate and any planned or delivered external beam radiation). A Foley catheter is also placed when you are asleep so that the urethra, as it passes through the prostate, can be visualized, and seeds/radiation can be planned to best minimize the dose to the urethra.
The Seed Implant process begins with your doctor placing small needles into the prostate gland through the perineum, which is the skin between the scrotum and the anus. The procedure is performed using real-time visualization of the prostate using an ultrasound probe that is placed in the rectum. Once a needle has been placed into the proper position within the prostate, the Radiation Oncologist is able to inject or “load” several radiation seeds through that particular needle, placing each one in an exact location. That needle is removed, and another one is placed in a slightly different but specific position. Once this needle has been loaded and seeds delivered, the same procedure continues until the entire prostate has been implanted with the appropriately determined number of seeds.
Once the procedure is completed, a “rectal spacer” may be placed to move the rectal tissue a bit away from the prostate and the radiation. Only occasionally, a Urologist will perform a cystoscopy as well to look into the bladder using a special scope inserted through the urethra. Next you are taken to the recovery area where you will rest until you wake and are more comfortable; and you would be discharged in about an hour or two, Typically, you would be given instructions on the relatively easy removal process of the Foley at home the next morning.
Am I a Candidate for Seed Implant?
The advantages of a Seed Implant are that the procedure only lasts an hour or so and it is performed on an outpatient basis. The disadvantages of a Seed Implant are that the side effects of the Seed Implant are more intense and longer lasting. Patients that have a very poor urinary function at baseline may therefore not be great candidates for seeds. Patients with a very large prostate or signs or with more advanced disease characteristics such as a Gleason score of 7 or higher, a PSA above 10 ng/ml or in certain situations based on pathologic findings on biopsy (such as the presence of perineural invasion) also may not be candidates, however in these cases external beam radiation can be combined with a seed implant. Your radiation oncologist can discuss seed implantation and whether it is right for you and your individual situation.
Are there any Preparations Prior to Having a Seed Implant?
You will be scheduled for a scan at one of Advanced Radiation Centers’ facilities several weeks before the Seed Implant procedure will take place. This scan typically takes only a few minutes to perform. You will be asked to schedule an appointment with your Internist or Cardiologist to get medical clearance and to ensure you are in appropriate health for the anesthesia and for the procedure itself. You may be required to go for pre-operative testing. A nursing coordinator or a staff member will provide you with full instructions about your procedure, information on the time / location you should arrive, and answer any questions you may have.
Can I Be Near Children After the Seed Implant?
You must keep a three foot distance from young children and pregnant women during either six weeks (in the case of Palladium) or three weeks (in the case of Cesium). Additional detailed instructions will be given to you when leaving the ambulatory center. You will NOT set off alarms in the airport, however, you will be given a wallet card indicating the amount of radioactivity that was implanted in case you ever need to show another physician how much radiation was delivered.
Are There Other Precautions to Take After the Seed Implant?
You should avoid strenuous exercise for at least the first two weeks and engage in only light exercise during the first week. Following the Seed Implant procedure, your Urologist may provide you with certain medications to take in the days or weeks following the implant to deal with any pain or urinary symptoms that you may have.
Short-Term (Acute) Side Effects of Seed Implantation
Some of the short-term side affects you may face in the days immediately following the procedure include slight soreness in the perineum-region where the needles for the implant were placed, and typically extra-strength Tylenol is usually enough to ease any such discomfort. Urinary symptoms can begin at this time as well. Your radiation oncologist or urologist will likely give you medications to help reduce or relieve some of these urinary symptoms. Also, during the ensuing months, you may experience slight fatigue, as well as rectal symptoms. You may also notice blood in the urine, semen, or stool, which typically will subside in 2-3 weeks.
Long-Term (Late) Side Effects of Seed Implantation
Risks include but are not limited to erectile dysfunction, loss or diminution of ejaculation, rectal irritation and bleeding and urinary obstruction.
Follow-Up Appointments
Following the seed implant, you will have a post-seed scan 4 weeks or so later, and then your first visit with your radiation oncologist will in about 2 weeks after that, or 6 weeks from the procedure date. After this first follow up, you will be seen by the Radiation Oncologist every six months for the first five years. During this time, a review of the PSA test that was performed by your Urologist will be made, along with a discussion of any possible symptoms you may be having. The Radiation Oncologist will also perform a physical exam which will give the physician important information. That information, along with the PSA test numbers, becomes an important predictor of how well things are going. The PSA is one of the more important “barometers” that help your doctor measure the efficacy of the radiation treatments months and years following therapy. It is equally important that routine follow-up appointments be made with your Urologist.
